Refactor to work on `char`s

Previously, a custom char implementation was used.
This was easier to work with, as sometimes “virtual” characters are injected,
or characters are ignored.

This replaces that with working on actual `char`s.
In the hope of in the future working on `u8`s, even.

This simplifies the state machine somewhat, as only `\n` is fed, regardless of
whether it was a CRLF, CR, or LF.
It also feeds `' '` instead of virtual spaces.

The BOM, if present, is now available as a `ByteOrderMark` event.

44 files changed, 1087 insertions, 1036 deletions

diff --git a/src/compiler.rs b/src/compiler.rs
index a575221..f5673b4 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -2,14 +2,14 @@
 use crate::constant::{SAFE_PROTOCOL_HREF, SAFE_PROTOCOL_SRC};
 use crate::construct::character_reference::Kind as CharacterReferenceKind;
 use crate::token::Token;
-use crate::tokenizer::{Code, Event, EventType};
+use crate::tokenizer::{Event, EventType};
 use crate::util::normalize_identifier::normalize_identifier;
 use crate::util::{
     decode_character_reference::{decode_named, decode_numeric},
     encode::encode,
     sanitize_uri::sanitize_uri,
     skip,
-    span::{codes as codes_from_span, from_exit_event, serialize},
+    slice::{Position, Slice},
 };
 use crate::{LineEnding, Options};
 
@@ -60,7 +60,7 @@ struct Definition {
 struct CompileContext<'a> {
     /// Static info.
     pub events: &'a [Event],
-    pub codes: &'a [Code],
+    pub chars: &'a [char],
     /// Fields used by handlers to track the things they need to track to
     /// compile markdown.
     pub atx_opening_sequence_size: Option<usize>,
@@ -76,7 +76,7 @@ struct CompileContext<'a> {
     /// Fields used to influance the current compilation.
     pub slurp_one_line_ending: bool,
     pub tags: bool,
-    pub ignore_encode: bool,
+    pub encode_html: bool,
     pub last_was_tag: bool,
     /// Configuration
     pub protocol_href: Option<Vec<&'static str>>,
@@ -92,13 +92,13 @@ impl<'a> CompileContext<'a> {
     /// Create a new compile context.
     pub fn new(
         events: &'a [Event],
-        codes: &'a [Code],
+        chars: &'a [char],
         options: &Options,
         line_ending: LineEnding,
     ) -> CompileContext<'a> {
         CompileContext {
             events,
-            codes,
+            chars,
             atx_opening_sequence_size: None,
             heading_setext_buffer: None,
             code_flow_seen_data: None,
@@ -111,7 +111,7 @@ impl<'a> CompileContext<'a> {
             tight_stack: vec![],
             slurp_one_line_ending: false,
             tags: true,
-            ignore_encode: false,
+            encode_html: true,
             last_was_tag: false,
             protocol_href: if options.allow_dangerous_protocol {
                 None
@@ -151,16 +151,13 @@ impl<'a> CompileContext<'a> {
 
     pub fn push_raw<'x, S: Into<&'x str>>(&mut self, value: S) {
         let value = value.into();
-        if self.ignore_encode {
-            self.push(value);
-        } else {
-            self.push(&*encode(value));
-        }
+        self.push(&*encode(value, self.encode_html));
     }
 
     pub fn tag<'x, S: Into<&'x str>>(&mut self, value: S) {
         if self.tags {
-            self.push(value.into());
+            let value = value.into();
+            self.push(&*encode(value, false));
             self.last_was_tag = true;
         }
     }
@@ -199,7 +196,7 @@ impl<'a> CompileContext<'a> {
 
 /// Turn events and codes into a string of HTML.
 #[allow(clippy::too_many_lines)]
-pub fn compile(events: &[Event], codes: &[Code], options: &Options) -> String {
+pub fn compile(events: &[Event], chars: &[char], options: &Options) -> String {
     let mut index = 0;
     let mut line_ending_inferred = None;
 
@@ -211,8 +208,9 @@ pub fn compile(events: &[Event], codes: &[Code], options: &Options) -> String {
         if event.event_type == EventType::Exit
             && (event.token_type == Token::BlankLineEnding || event.token_type == Token::LineEnding)
         {
-            let codes = codes_from_span(codes, &from_exit_event(events, index));
-            line_ending_inferred = Some(LineEnding::from_code(*codes.first().unwrap()));
+            line_ending_inferred = Some(LineEnding::from_str(
+                &Slice::from_position(chars, &Position::from_exit_event(events, index)).serialize(),
+            ));
             break;
         }
 
@@ -239,7 +237,7 @@ pub fn compile(events: &[Event], codes: &[Code], options: &Options) -> String {
         }
     };
 
-    let mut context = CompileContext::new(events, codes, options, line_ending_default);
+    let mut context = CompileContext::new(events, chars, options, line_ending_default);
     let mut definition_indices = vec![];
     let mut index = 0;
     let mut definition_inside = false;
@@ -441,7 +439,7 @@ fn on_enter_definition(context: &mut CompileContext) {
 /// Handle [`Enter`][EventType::Enter]:[`DefinitionDestinationString`][Token::DefinitionDestinationString].
 fn on_enter_definition_destination_string(context: &mut CompileContext) {
     context.buffer();
-    context.ignore_encode = true;
+    context.encode_html = false;
 }
 
 /// Handle [`Enter`][EventType::Enter]:[`Emphasis`][Token::Emphasis].
@@ -453,14 +451,14 @@ fn on_enter_emphasis(context: &mut CompileContext) {
 fn on_enter_html_flow(context: &mut CompileContext) {
     context.line_ending_if_needed();
     if context.allow_dangerous_html {
-        context.ignore_encode = true;
+        context.encode_html = false;
     }
 }
 
 /// Handle [`Enter`][EventType::Enter]:[`HtmlText`][Token::HtmlText].
 fn on_enter_html_text(context: &mut CompileContext) {
     if context.allow_dangerous_html {
-        context.ignore_encode = true;
+        context.encode_html = false;
     }
 }
 
@@ -595,7 +593,7 @@ fn on_enter_resource_destination_string(context: &mut CompileContext) {
     context.buffer();
     // Ignore encoding the result, as we’ll first percent encode the url and
     // encode manually after.
-    context.ignore_encode = true;
+    context.encode_html = false;
 }
 
 /// Handle [`Enter`][EventType::Enter]:[`Strong`][Token::Strong].
@@ -605,34 +603,36 @@ fn on_enter_strong(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:[`AutolinkEmail`][Token::AutolinkEmail].
 fn on_exit_autolink_email(context: &mut CompileContext) {
-    let slice = serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    );
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     context.tag(&*format!(
         "<a href=\"{}\">",
         sanitize_uri(
-            format!("mailto:{}", slice.as_str()).as_str(),
+            format!("mailto:{}", value.as_str()).as_str(),
             &context.protocol_href
         )
     ));
-    context.push_raw(&*slice);
+    context.push_raw(&*value);
     context.tag("</a>");
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`AutolinkProtocol`][Token::AutolinkProtocol].
 fn on_exit_autolink_protocol(context: &mut CompileContext) {
-    let slice = serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    );
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     context.tag(&*format!(
         "<a href=\"{}\">",
-        sanitize_uri(slice.as_str(), &context.protocol_href)
+        sanitize_uri(value.as_str(), &context.protocol_href)
     ));
-    context.push_raw(&*slice);
+    context.push_raw(&*value);
     context.tag("</a>");
 }
 
@@ -677,11 +677,12 @@ fn on_exit_character_reference_value(context: &mut CompileContext) {
         .character_reference_kind
         .take()
         .expect("expected `character_reference_kind` to be set");
-    let reference = serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    );
+    let reference = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     let ref_string = reference.as_str();
     let value = match kind {
         CharacterReferenceKind::Decimal => decode_numeric(ref_string, 10).to_string(),
@@ -694,12 +695,14 @@ fn on_exit_character_reference_value(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:[`CodeFlowChunk`][Token::CodeFlowChunk].
 fn on_exit_code_flow_chunk(context: &mut CompileContext) {
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     context.code_flow_seen_data = Some(true);
-    context.push_raw(&*serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    ));
+    context.push_raw(&*value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`CodeFencedFence`][Token::CodeFencedFence].
@@ -793,12 +796,14 @@ fn on_exit_drop(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:{[`CodeTextData`][Token::CodeTextData],[`Data`][Token::Data],[`CharacterEscapeValue`][Token::CharacterEscapeValue]}.
 fn on_exit_data(context: &mut CompileContext) {
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     // Just output it.
-    context.push_raw(&*serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    ));
+    context.push_raw(&*value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`Definition`][Token::Definition].
@@ -830,19 +835,21 @@ fn on_exit_definition_destination_string(context: &mut CompileContext) {
     let buf = context.resume();
     let definition = context.media_stack.last_mut().unwrap();
     definition.destination = Some(buf);
-    context.ignore_encode = false;
+    context.encode_html = true;
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`DefinitionLabelString`][Token::DefinitionLabelString].
 fn on_exit_definition_label_string(context: &mut CompileContext) {
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     // Discard label, use the source content instead.
     context.resume();
     let definition = context.media_stack.last_mut().unwrap();
-    definition.reference_id = Some(serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    ));
+    definition.reference_id = Some(value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`DefinitionTitleString`][Token::DefinitionTitleString].
@@ -871,12 +878,11 @@ fn on_exit_heading_atx(context: &mut CompileContext) {
 fn on_exit_heading_atx_sequence(context: &mut CompileContext) {
     // First fence we see.
     if context.atx_opening_sequence_size.is_none() {
-        let rank = serialize(
-            context.codes,
-            &from_exit_event(context.events, context.index),
-            false,
+        let rank = Slice::from_position(
+            context.chars,
+            &Position::from_exit_event(context.events, context.index),
         )
-        .len();
+        .size();
         context.line_ending_if_needed();
         context.atx_opening_sequence_size = Some(rank);
         context.tag(&*format!("<h{}>", rank));
@@ -902,11 +908,12 @@ fn on_exit_heading_setext_underline(context: &mut CompileContext) {
         .heading_setext_buffer
         .take()
         .expect("`atx_opening_sequence_size` must be set in headings");
-    let head = codes_from_span(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-    )[0];
-    let level: usize = if head == Code::Char('-') { 2 } else { 1 };
+    let head = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .head();
+    let level = if head == Some('-') { 2 } else { 1 };
 
     context.line_ending_if_needed();
     context.tag(&*format!("<h{}>", level));
@@ -916,17 +923,18 @@ fn on_exit_heading_setext_underline(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:{[`HtmlFlow`][Token::HtmlFlow],[`HtmlText`][Token::HtmlText]}.
 fn on_exit_html(context: &mut CompileContext) {
-    context.ignore_encode = false;
+    context.encode_html = true;
 }
 
 /// Handle [`Exit`][EventType::Exit]:{[`HtmlFlowData`][Token::HtmlFlowData],[`HtmlTextData`][Token::HtmlTextData]}.
 fn on_exit_html_data(context: &mut CompileContext) {
-    let slice = serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    );
-    context.push_raw(&*slice);
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
+    context.push_raw(&*value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`Label`][Token::Label].
@@ -938,12 +946,14 @@ fn on_exit_label(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:[`LabelText`][Token::LabelText].
 fn on_exit_label_text(context: &mut CompileContext) {
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     let media = context.media_stack.last_mut().unwrap();
-    media.label_id = Some(serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    ));
+    media.label_id = Some(value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`LineEnding`][Token::LineEnding].
@@ -953,11 +963,13 @@ fn on_exit_line_ending(context: &mut CompileContext) {
     } else if context.slurp_one_line_ending {
         context.slurp_one_line_ending = false;
     } else {
-        context.push_raw(&*serialize(
-            context.codes,
-            &from_exit_event(context.events, context.index),
-            false,
-        ));
+        let value = Slice::from_position(
+            context.chars,
+            &Position::from_exit_event(context.events, context.index),
+        )
+        .serialize();
+
+        context.push_raw(&*value);
     }
 }
 
@@ -1004,12 +1016,12 @@ fn on_exit_list_item_value(context: &mut CompileContext) {
     let expect_first_item = context.expect_first_item.unwrap();
 
     if expect_first_item {
-        let slice = serialize(
-            context.codes,
-            &from_exit_event(context.events, context.index),
-            false,
-        );
-        let value = slice.parse::<u32>().ok().unwrap();
+        let value = Slice::from_position(
+            context.chars,
+            &Position::from_exit_event(context.events, context.index),
+        )
+        .serialize();
+        let value = value.parse::<u32>().ok().unwrap();
 
         if value != 1 {
             context.tag(" start=\"");
@@ -1110,14 +1122,16 @@ fn on_exit_paragraph(context: &mut CompileContext) {
 
 /// Handle [`Exit`][EventType::Exit]:[`ReferenceString`][Token::ReferenceString].
 fn on_exit_reference_string(context: &mut CompileContext) {
+    let value = Slice::from_position(
+        context.chars,
+        &Position::from_exit_event(context.events, context.index),
+    )
+    .serialize();
+
     // Drop stuff.
     context.resume();
     let media = context.media_stack.last_mut().unwrap();
-    media.reference_id = Some(serialize(
-        context.codes,
-        &from_exit_event(context.events, context.index),
-        false,
-    ));
+    media.reference_id = Some(value);
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`ResourceDestinationString`][Token::ResourceDestinationString].
@@ -1125,7 +1139,7 @@ fn on_exit_resource_destination_string(context: &mut CompileContext) {
     let buf = context.resume();
     let media = context.media_stack.last_mut().unwrap();
     media.destination = Some(buf);
-    context.ignore_encode = false;
+    context.encode_html = true;
 }
 
 /// Handle [`Exit`][EventType::Exit]:[`ResourceTitleString`][Token::ResourceTitleString].
diff --git a/src/constant.rs b/src/constant.rs
index b8b36ad..d84dda5 100644
--- a/src/constant.rs
+++ b/src/constant.rs
@@ -232,11 +232,7 @@ pub const SAFE_PROTOCOL_SRC: [&str; 2] = ["http", "https"];
 /// constructs in markdown, most notable the whitespace required to form
 /// [code (indented)][code_indented].
 ///
-/// > 👉 **Note**: each [`Code::VirtualSpace`][vs] and `Code::Char('\t' | ' ')`
-/// > counts.
-///
 /// [code_indented]: crate::construct::code_indented
-/// [vs]: crate::tokenizer::Code::VirtualSpace
 pub const TAB_SIZE: usize = 4;
 
 /// The number of markers needed for a [thematic break][thematic_break] to form.
diff --git a/src/construct/attention.rs b/src/construct/attention.rs
index 27d7544..65c2f6f 100644
--- a/src/construct/attention.rs
+++ b/src/construct/attention.rs
@@ -52,8 +52,9 @@
 //! [html-strong]: https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-strong-element
 
 use crate::token::Token;
-use crate::tokenizer::{Code, Event, EventType, Point, State, Tokenizer};
+use crate::tokenizer::{Event, EventType, Point, State, Tokenizer};
 use crate::unicode::PUNCTUATION;
+use crate::util::slice::Slice;
 
 /// Character code kinds.
 #[derive(Debug, PartialEq)]
@@ -128,17 +129,6 @@ impl MarkerKind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not `Code::Char('*' | '_')`.
-    fn from_code(code: Code) -> MarkerKind {
-        match code {
-            Code::Char(char) => MarkerKind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// Attentention sequence that we can take markers from.
@@ -170,9 +160,9 @@ struct Sequence {
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('*' | '_') if tokenizer.parse_state.constructs.attention => {
+        Some(char) if tokenizer.parse_state.constructs.attention && matches!(char, '*' | '_') => {
             tokenizer.enter(Token::AttentionSequence);
-            inside(tokenizer, MarkerKind::from_code(tokenizer.current))
+            inside(tokenizer, MarkerKind::from_char(char))
         }
         _ => State::Nok,
     }
@@ -185,23 +175,20 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 ///     ^^
 /// ```
 fn inside(tokenizer: &mut Tokenizer, marker: MarkerKind) -> State {
-    match tokenizer.current {
-        Code::Char(char) if char == marker.as_char() => {
-            tokenizer.consume();
-            State::Fn(Box::new(move |t| inside(t, marker)))
-        }
-        _ => {
-            tokenizer.exit(Token::AttentionSequence);
-            tokenizer.register_resolver("attention".to_string(), Box::new(resolve_attention));
-            State::Ok
-        }
+    if tokenizer.current == Some(marker.as_char()) {
+        tokenizer.consume();
+        State::Fn(Box::new(move |t| inside(t, marker)))
+    } else {
+        tokenizer.exit(Token::AttentionSequence);
+        tokenizer.register_resolver("attention".to_string(), Box::new(resolve_attention));
+        State::Ok
     }
 }
 
 /// Resolve attention sequences.
 #[allow(clippy::too_many_lines)]
 fn resolve_attention(tokenizer: &mut Tokenizer) {
-    let codes = &tokenizer.parse_state.codes;
+    let chars = &tokenizer.parse_state.chars;
     let mut start = 0;
     let mut balance = 0;
     let mut sequences = vec![];
@@ -216,17 +203,21 @@ fn resolve_attention(tokenizer: &mut Tokenizer) {
             if enter.token_type == Token::AttentionSequence {
                 let end = start + 1;
                 let exit = &tokenizer.events[end];
-                let marker = MarkerKind::from_code(codes[enter.point.index]);
+                let marker =
+                    MarkerKind::from_char(Slice::from_point(chars, &enter.point).head().unwrap());
                 let before = classify_character(if enter.point.index > 0 {
-                    codes[enter.point.index - 1]
-                } else {
-                    Code::None
-                });
-                let after = classify_character(if exit.point.index < codes.len() {
-                    codes[exit.point.index]
+                    Slice::from_point(
+                        chars,
+                        &Point {
+                            index: enter.point.index - 1,
+                            ..enter.point
+                        },
+                    )
+                    .tail()
                 } else {
-                    Code::None
+                    None
                 });
+                let after = classify_character(Slice::from_point(chars, &exit.point).tail());
                 let open = after == GroupKind::Other
                     || (after == GroupKind::Punctuation && before != GroupKind::Other);
                 // To do: GFM strikethrough?
@@ -326,9 +317,9 @@ fn resolve_attention(tokenizer: &mut Tokenizer) {
                     let sequence_close = &mut sequences[close];
                     let close_event_index = sequence_close.event_index;
                     let seq_close_enter = sequence_close.start_point.clone();
+                    // No need to worry about `VS`, because sequences are only actual characters.
                     sequence_close.size -= take;
                     sequence_close.start_point.column += take;
-                    sequence_close.start_point.offset += take;
                     sequence_close.start_point.index += take;
                     let seq_close_exit = sequence_close.start_point.clone();
 
@@ -352,9 +343,9 @@ fn resolve_attention(tokenizer: &mut Tokenizer) {
                     let sequence_open = &mut sequences[open];
                     let open_event_index = sequence_open.event_index;
                     let seq_open_exit = sequence_open.end_point.clone();
+                    // No need to worry about `VS`, because sequences are only actual characters.
                     sequence_open.size -= take;
                     sequence_open.end_point.column -= take;
-                    sequence_open.end_point.offset -= take;
                     sequence_open.end_point.index -= take;
                     let seq_open_enter = sequence_open.end_point.clone();
 
@@ -492,20 +483,20 @@ fn resolve_attention(tokenizer: &mut Tokenizer) {
 /// Used for attention (emphasis, strong), whose sequences can open or close
 /// based on the class of surrounding characters.
 ///
-/// > 👉 **Note** that eof (`Code::None`) is seen as whitespace.
+/// > 👉 **Note** that eof (`None`) is seen as whitespace.
 ///
 /// ## References
 ///
 /// *   [`micromark-util-classify-character` in `micromark`](https://github.com/micromark/micromark/blob/main/packages/micromark-util-classify-character/dev/index.js)
-fn classify_character(code: Code) -> GroupKind {
-    match code {
+fn classify_character(char: Option<char>) -> GroupKind {
+    match char {
         // Custom characters.
-        Code::None | Code::CarriageReturnLineFeed | Code::VirtualSpace => GroupKind::Whitespace,
+        None => GroupKind::Whitespace,
         // Unicode whitespace.
-        Code::Char(char) if char.is_whitespace() => GroupKind::Whitespace,
+        Some(char) if char.is_whitespace() => GroupKind::Whitespace,
         // Unicode punctuation.
-        Code::Char(char) if PUNCTUATION.contains(&char) => GroupKind::Punctuation,
+        Some(char) if PUNCTUATION.contains(&char) => GroupKind::Punctuation,
         // Everything else.
-        Code::Char(_) => GroupKind::Other,
+        Some(_) => GroupKind::Other,
     }
 }
diff --git a/src/construct/autolink.rs b/src/construct/autolink.rs
index 3933596..399570b 100644
--- a/src/construct/autolink.rs
+++ b/src/construct/autolink.rs
@@ -103,7 +103,7 @@
 
 use crate::constant::{AUTOLINK_DOMAIN_SIZE_MAX, AUTOLINK_SCHEME_SIZE_MAX};
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of an autolink.
 ///
@@ -115,7 +115,7 @@ use crate::tokenizer::{Code, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('<') if tokenizer.parse_state.constructs.autolink => {
+        Some('<') if tokenizer.parse_state.constructs.autolink => {
             tokenizer.enter(Token::Autolink);
             tokenizer.enter(Token::AutolinkMarker);
             tokenizer.consume();
@@ -137,11 +137,11 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(char) if char.is_ascii_alphabetic() => {
+        Some(char) if char.is_ascii_alphabetic() => {
             tokenizer.consume();
             State::Fn(Box::new(scheme_or_email_atext))
         }
-        Code::Char(char) if is_ascii_atext(char) => email_atext(tokenizer),
+        Some(char) if is_ascii_atext(char) => email_atext(tokenizer),
         _ => State::Nok,
     }
 }
@@ -156,7 +156,7 @@ fn open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn scheme_or_email_atext(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('+' | '-' | '.' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
+        Some('+' | '-' | '.' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
             scheme_inside_or_email_atext(tokenizer, 1)
         }
         _ => email_atext(tokenizer),
@@ -173,11 +173,11 @@ fn scheme_or_email_atext(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn scheme_inside_or_email_atext(tokenizer: &mut Tokenizer, size: usize) -> State {
     match tokenizer.current {
-        Code::Char(':') => {
+        Some(':') => {
             tokenizer.consume();
             State::Fn(Box::new(url_inside))
         }
-        Code::Char('+' | '-' | '.' | '0'..='9' | 'A'..='Z' | 'a'..='z')
+        Some('+' | '-' | '.' | '0'..='9' | 'A'..='Z' | 'a'..='z')
             if size < AUTOLINK_SCHEME_SIZE_MAX =>
         {
             tokenizer.consume();
@@ -195,15 +195,13 @@ fn scheme_inside_or_email_atext(tokenizer: &mut Tokenizer, size: usize) -> State
 /// ```
 fn url_inside(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.exit(Token::AutolinkProtocol);
             end(tokenizer)
         }
-        Code::Char(char) if char.is_ascii_control() => State::Nok,
-        Code::None | Code::CarriageReturnLineFeed | Code::VirtualSpace | Code::Char(' ') => {
-            State::Nok
-        }
-        Code::Char(_) => {
+        Some(char) if char.is_ascii_control() => State::Nok,
+        None | Some(' ') => State::Nok,
+        Some(_) => {
             tokenizer.consume();
             State::Fn(Box::new(url_inside))
         }
@@ -218,11 +216,11 @@ fn url_inside(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn email_atext(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('@') => {
+        Some('@') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| email_at_sign_or_dot(t, 0)))
         }
-        Code::Char(char) if is_ascii_atext(char) => {
+        Some(char) if is_ascii_atext(char) => {
             tokenizer.consume();
             State::Fn(Box::new(email_atext))
         }
@@ -238,7 +236,7 @@ fn email_atext(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn email_at_sign_or_dot(tokenizer: &mut Tokenizer, size: usize) -> State {
     match tokenizer.current {
-        Code::Char(char) if char.is_ascii_alphanumeric() => email_value(tokenizer, size),
+        Some(char) if char.is_ascii_alphanumeric() => email_value(tokenizer, size),
         _ => State::Nok,
     }
 }
@@ -251,11 +249,11 @@ fn email_at_sign_or_dot(tokenizer: &mut Tokenizer, size: usize) -> State {
 /// ```
 fn email_label(tokenizer: &mut Tokenizer, size: usize) -> State {
     match tokenizer.current {
-        Code::Char('.') => {
+        Some('.') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| email_at_sign_or_dot(t, 0)))
         }
-        Code::Char('>') => {
+        Some('>') => {
             let index = tokenizer.events.len();
             tokenizer.exit(Token::AutolinkProtocol);
             // Change the token type.
@@ -277,11 +275,11 @@ fn email_label(tokenizer: &mut Tokenizer, size: usize) -> State {
 /// ```
 fn email_value(tokenizer: &mut Tokenizer, size: usize) -> State {
     match tokenizer.current {
-        Code::Char('-') if size < AUTOLINK_DOMAIN_SIZE_MAX => {
+        Some('-') if size < AUTOLINK_DOMAIN_SIZE_MAX => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| email_value(t, size + 1)))
         }
-        Code::Char(char) if char.is_ascii_alphanumeric() && size < AUTOLINK_DOMAIN_SIZE_MAX => {
+        Some(char) if char.is_ascii_alphanumeric() && size < AUTOLINK_DOMAIN_SIZE_MAX => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| email_label(t, size + 1)))
         }
@@ -299,7 +297,7 @@ fn email_value(tokenizer: &mut Tokenizer, size: usize) -> State {
 /// ```
 fn end(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.enter(Token::AutolinkMarker);
             tokenizer.consume();
             tokenizer.exit(Token::AutolinkMarker);
diff --git a/src/construct/blank_line.rs b/src/construct/blank_line.rs
index 537ffc1..6780f40 100644
--- a/src/construct/blank_line.rs
+++ b/src/construct/blank_line.rs
@@ -33,7 +33,7 @@
 //! [flow]: crate::content::flow
 
 use crate::construct::partial_space_or_tab::space_or_tab;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of a blank line.
 ///
@@ -59,7 +59,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => State::Ok,
+        None | Some('\n') => State::Ok,
         _ => State::Nok,
     }
 }
diff --git a/src/construct/block_quote.rs b/src/construct/block_quote.rs
index 3bb4b8b..49a0ea0 100644
--- a/src/construct/block_quote.rs
+++ b/src/construct/block_quote.rs
@@ -36,7 +36,7 @@
 use crate::constant::TAB_SIZE;
 use crate::construct::partial_space_or_tab::space_or_tab_min_max;
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of block quote.
 ///
@@ -65,7 +65,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.enter(Token::BlockQuote);
             cont_before(tokenizer)
         }
@@ -98,7 +98,7 @@ pub fn cont(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn cont_before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.enter(Token::BlockQuotePrefix);
             tokenizer.enter(Token::BlockQuoteMarker);
             tokenizer.consume();
@@ -118,17 +118,14 @@ fn cont_before(tokenizer: &mut Tokenizer) -> State {
 ///      ^
 /// ```
 fn cont_after(tokenizer: &mut Tokenizer) -> State {
-    match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
-            tokenizer.enter(Token::SpaceOrTab);
-            tokenizer.consume();
-            tokenizer.exit(Token::SpaceOrTab);
-            tokenizer.exit(Token::BlockQuotePrefix);
-            State::Ok
-        }
-        _ => {
-            tokenizer.exit(Token::BlockQuotePrefix);
-            State::Ok
-        }
+    if let Some('\t' | ' ') = tokenizer.current {
+        tokenizer.enter(Token::SpaceOrTab);
+        tokenizer.consume();
+        tokenizer.exit(Token::SpaceOrTab);
+        tokenizer.exit(Token::BlockQuotePrefix);
+        State::Ok
+    } else {
+        tokenizer.exit(Token::BlockQuotePrefix);
+        State::Ok
     }
 }
diff --git a/src/construct/character_escape.rs b/src/construct/character_escape.rs
index 9e9b713..e9263af 100644
--- a/src/construct/character_escape.rs
+++ b/src/construct/character_escape.rs
@@ -34,7 +34,7 @@
 //! [hard_break_escape]: crate::construct::hard_break_escape
 
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of a character escape.
 ///
@@ -44,7 +44,7 @@ use crate::tokenizer::{Code, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('\\') if tokenizer.parse_state.constructs.character_escape => {
+        Some('\\') if tokenizer.parse_state.constructs.character_escape => {
             tokenizer.enter(Token::CharacterEscape);
             tokenizer.enter(Token::CharacterEscapeMarker);
             tokenizer.consume();
@@ -63,7 +63,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(char) if char.is_ascii_punctuation() => {
+        Some(char) if char.is_ascii_punctuation() => {
             tokenizer.enter(Token::CharacterEscapeValue);
             tokenizer.consume();
             tokenizer.exit(Token::CharacterEscapeValue);
diff --git a/src/construct/character_reference.rs b/src/construct/character_reference.rs
index 8521f15..59043d1 100644
--- a/src/construct/character_reference.rs
+++ b/src/construct/character_reference.rs
@@ -66,7 +66,8 @@ use crate::constant::{
     CHARACTER_REFERENCE_HEXADECIMAL_SIZE_MAX, CHARACTER_REFERENCE_NAMED_SIZE_MAX,
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{Point, State, Tokenizer};
+use crate::util::slice::{Position, Slice};
 
 /// Kind of a character reference.
 #[derive(Debug, Clone, PartialEq)]
@@ -120,8 +121,10 @@ impl Kind {
 /// State needed to parse character references.
 #[derive(Debug, Clone)]
 struct Info {
-    /// All parsed characters.
-    buffer: String,
+    /// Place of value start.
+    start: Point,
+    /// Size of value.
+    size: usize,
     /// Kind of character reference.
     kind: Kind,
 }
@@ -138,7 +141,7 @@ struct Info {
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('&') if tokenizer.parse_state.constructs.character_reference => {
+        Some('&') if tokenizer.parse_state.constructs.character_reference => {
             tokenizer.enter(Token::CharacterReference);
             tokenizer.enter(Token::CharacterReferenceMarker);
             tokenizer.consume();
@@ -161,18 +164,21 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 ///       ^
 /// ```
 fn open(tokenizer: &mut Tokenizer) -> State {
-    let info = Info {
-        buffer: String::new(),
-        kind: Kind::Named,
-    };
-    if let Code::Char('#') = tokenizer.current {
+    if let Some('#') = tokenizer.current {
         tokenizer.enter(Token::CharacterReferenceMarkerNumeric);
         tokenizer.consume();
         tokenizer.exit(Token::CharacterReferenceMarkerNumeric);
-        State::Fn(Box::new(|t| numeric(t, info)))
+        State::Fn(Box::new(numeric))
     } else {
         tokenizer.enter(Token::CharacterReferenceValue);
-        value(tokenizer, info)
+        value(
+            tokenizer,
+            Info {
+                start: tokenizer.point.clone(),
+                size: 0,
+                kind: Kind::Named,
+            },
+        )
     }
 }
 
@@ -185,17 +191,25 @@ fn open(tokenizer: &mut Tokenizer) -> State {
 /// > | a&#x9;b
 ///        ^
 /// ```
-fn numeric(tokenizer: &mut Tokenizer, mut info: Info) -> State {
-    if let Code::Char('x' | 'X') = tokenizer.current {
+fn numeric(tokenizer: &mut Tokenizer) -> State {
+    if let Some('x' | 'X') = tokenizer.current {
         tokenizer.enter(Token::CharacterReferenceMarkerHexadecimal);
         tokenizer.consume();
         tokenizer.exit(Token::CharacterReferenceMarkerHexadecimal);
         tokenizer.enter(Token::CharacterReferenceValue);
-        info.kind = Kind::Hexadecimal;
+        let info = Info {
+            start: tokenizer.point.clone(),
+            size: 0,
+            kind: Kind::Hexadecimal,
+        };
         State::Fn(Box::new(|t| value(t, info)))
     } else {
         tokenizer.enter(Token::CharacterReferenceValue);
-        info.kind = Kind::Decimal;
+        let info = Info {
+            start: tokenizer.point.clone(),
+            size: 0,
+            kind: Kind::Decimal,
+        };
         value(tokenizer, info)
     }
 }
@@ -215,24 +229,32 @@ fn numeric(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn value(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char(';') if !info.buffer.is_empty() => {
-            let unknown_named = Kind::Named == info.kind
-                && !CHARACTER_REFERENCES.iter().any(|d| d.0 == info.buffer);
+        Some(';') if info.size > 0 => {
+            if Kind::Named == info.kind {
+                let value = Slice::from_position(
+                    &tokenizer.parse_state.chars,
+                    &Position {
+                        start: &info.start,
+                        end: &tokenizer.point,
+                    },
+                )
+                .serialize();
 
-            if unknown_named {
-                State::Nok
-            } else {
-                tokenizer.exit(Token::CharacterReferenceValue);
-                tokenizer.enter(Token::CharacterReferenceMarkerSemi);
-                tokenizer.consume();
-                tokenizer.exit(Token::CharacterReferenceMarkerSemi);
-                tokenizer.exit(Token::CharacterReference);
-                State::Ok
+                if !CHARACTER_REFERENCES.iter().any(|d| d.0 == value) {
+                    return State::Nok;
+                }
             }
+
+            tokenizer.exit(Token::CharacterReferenceValue);
+            tokenizer.enter(Token::CharacterReferenceMarkerSemi);
+            tokenizer.consume();
+            tokenizer.exit(Token::CharacterReferenceMarkerSemi);
+            tokenizer.exit(Token::CharacterReference);
+            State::Ok
         }
-        Code::Char(char) => {
-            if info.buffer.len() < info.kind.max() && info.kind.allowed(char) {
-                info.buffer.push(char);
+        Some(char) => {
+            if info.size < info.kind.max() && info.kind.allowed(char) {
+                info.size += 1;
                 tokenizer.consume();
                 State::Fn(Box::new(|t| value(t, info)))
             } else {
diff --git a/src/construct/code_fenced.rs b/src/construct/code_fenced.rs
index 2fea95e..98fa54f 100644
--- a/src/construct/code_fenced.rs
+++ b/src/construct/code_fenced.rs
@@ -107,8 +107,8 @@ use crate::construct::{
     partial_space_or_tab::{space_or_tab, space_or_tab_min_max},
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, State, Tokenizer};
-use crate::util::span::from_exit_event;
+use crate::tokenizer::{ContentType, State, Tokenizer};
+use crate::util::slice::{Position, Slice};
 
 /// Kind of fences.
 #[derive(Debug, Clone, PartialEq)]
@@ -155,17 +155,6 @@ impl Kind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not ``Code::Char('~' | '`')``.
-    fn from_code(code: Code) -> Kind {
-        match code {
-            Code::Char(char) => Kind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// State needed to parse code (fenced).
@@ -217,20 +206,23 @@ fn before_sequence_open(tokenizer: &mut Tokenizer) -> State {
 
     if let Some(event) = tail {
         if event.token_type == Token::SpaceOrTab {
-            let span = from_exit_event(&tokenizer.events, tokenizer.events.len() - 1);
-            prefix = span.end_index - span.start_index;
+            prefix = Slice::from_position(
+                &tokenizer.parse_state.chars,
+                &Position::from_exit_event(&tokenizer.events, tokenizer.events.len() - 1),
+            )
+            .size();
         }
     }
 
     match tokenizer.current {
-        Code::Char('`' | '~') => {
+        Some(char) if matches!(char, '`' | '~') => {
             tokenizer.enter(Token::CodeFencedFenceSequence);
             sequence_open(
                 tokenizer,
                 Info {
                     prefix,
                     size: 0,
-                    kind: Kind::from_code(tokenizer.current),
+                    kind: Kind::from_char(char),
                 },
             )
         }
@@ -248,7 +240,7 @@ fn before_sequence_open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn sequence_open(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.consume();
             State::Fn(Box::new(|t| {
                 info.size += 1;
@@ -273,7 +265,7 @@ fn sequence_open(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn info_before(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::CodeFencedFence);
             // Do not form containers.
             tokenizer.concrete = true;
@@ -282,7 +274,7 @@ fn info_before(tokenizer: &mut Tokenizer, info: Info) -> State {
         _ => {
             tokenizer.enter(Token::CodeFencedFenceInfo);
             tokenizer.enter_with_content(Token::Data, Some(ContentType::String));
-            info_inside(tokenizer, info, vec![])
+            info_inside(tokenizer, info)
         }
     }
 }
@@ -295,9 +287,9 @@ fn info_before(tokenizer: &mut Tokenizer, info: Info) -> State {
 ///   | console.log(1)
 ///   | ~~~
 /// ```
-fn info_inside(tokenizer: &mut Tokenizer, info: Info, mut codes: Vec<Code>) -> State {
+fn info_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::Data);
             tokenizer.exit(Token::CodeFencedFenceInfo);
             tokenizer.exit(Token::CodeFencedFence);
@@ -305,16 +297,15 @@ fn info_inside(tokenizer: &mut Tokenizer, info: Info, mut codes: Vec<Code>) -> S
             tokenizer.concrete = true;
             at_break(tokenizer, info)
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.exit(Token::Data);
             tokenizer.exit(Token::CodeFencedFenceInfo);
             tokenizer.attempt_opt(space_or_tab(), |t| meta_before(t, info))(tokenizer)
         }
-        Code::Char('`') if info.kind == Kind::GraveAccent => State::Nok,
-        Code::Char(_) => {
-            codes.push(tokenizer.current);
+        Some('`') if info.kind == Kind::GraveAccent => State::Nok,
+        Some(_) => {
             tokenizer.consume();
-            State::Fn(Box::new(|t| info_inside(t, info, codes)))
+            State::Fn(Box::new(|t| info_inside(t, info)))
         }
     }
 }
@@ -329,7 +320,7 @@ fn info_inside(tokenizer: &mut Tokenizer, info: Info, mut codes: Vec<Code>) -> S
 /// ```
 fn meta_before(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::CodeFencedFence);
             // Do not form containers.
             tokenizer.concrete = true;
@@ -353,7 +344,7 @@ fn meta_before(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn meta(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::Data);
             tokenizer.exit(Token::CodeFencedFenceMeta);
             tokenizer.exit(Token::CodeFencedFence);
@@ -361,7 +352,7 @@ fn meta(tokenizer: &mut Tokenizer, info: Info) -> State {
             tokenizer.concrete = true;
             at_break(tokenizer, info)
         }
-        Code::Char('`') if info.kind == Kind::GraveAccent => State::Nok,
+        Some('`') if info.kind == Kind::GraveAccent => State::Nok,
         _ => {
             tokenizer.consume();
             State::Fn(Box::new(|t| meta(t, info)))
@@ -422,7 +413,7 @@ fn at_non_lazy_break(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn close_begin(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
@@ -461,7 +452,7 @@ fn close_start(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn close_before(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.enter(Token::CodeFencedFenceSequence);
             close_sequence(tokenizer, info, 0)
         }
@@ -479,7 +470,7 @@ fn close_before(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn close_sequence(tokenizer: &mut Tokenizer, info: Info, size: usize) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| close_sequence(t, info, size + 1)))
         }
@@ -501,7 +492,7 @@ fn close_sequence(tokenizer: &mut Tokenizer, info: Info, size: usize) -> State {
 /// ```
 fn close_sequence_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::CodeFencedFence);
             State::Ok
         }
@@ -547,9 +538,7 @@ fn content_start(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn content_begin(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_break(tokenizer, info)
-        }
+        None | Some('\n') => at_break(tokenizer, info),
         _ => {
             tokenizer.enter(Token::CodeFlowChunk);
             content_continue(tokenizer, info)
@@ -567,7 +556,7 @@ fn content_begin(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn content_continue(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::CodeFlowChunk);
             at_break(tokenizer, info)
         }
diff --git a/src/construct/code_indented.rs b/src/construct/code_indented.rs
index 015c4a0..bb1615c 100644
--- a/src/construct/code_indented.rs
+++ b/src/construct/code_indented.rs
@@ -48,7 +48,7 @@
 use super::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
 use crate::constant::TAB_SIZE;
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of code (indented).
 ///
@@ -78,11 +78,10 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn at_break(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => after(tokenizer),
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => tokenizer
-            .attempt(further_start, |ok| {
-                Box::new(if ok { at_break } else { after })
-            })(tokenizer),
+        None => after(tokenizer),
+        Some('\n') => tokenizer.attempt(further_start, |ok| {
+            Box::new(if ok { at_break } else { after })
+        })(tokenizer),
         _ => {
             tokenizer.enter(Token::CodeFlowChunk);
             content(tokenizer)
@@ -98,7 +97,7 @@ fn at_break(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn content(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::CodeFlowChunk);
             at_break(tokenizer)
         }
@@ -134,7 +133,7 @@ fn further_start(tokenizer: &mut Tokenizer) -> State {
         State::Nok
     } else {
         match tokenizer.current {
-            Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+            Some('\n') => {
                 tokenizer.enter(Token::LineEnding);
                 tokenizer.consume();
                 tokenizer.exit(Token::LineEnding);
@@ -178,7 +177,7 @@ fn further_begin(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn further_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => further_start(tokenizer),
+        Some('\n') => further_start(tokenizer),
         _ => State::Nok,
     }
 }
diff --git a/src/construct/code_text.rs b/src/construct/code_text.rs
index f5f92fc..150f63b 100644
--- a/src/construct/code_text.rs
+++ b/src/construct/code_text.rs
@@ -84,7 +84,7 @@
 //! [html-code]: https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-code-element
 
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of code (text).
 ///
@@ -98,9 +98,9 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
     let len = tokenizer.events.len();
 
     match tokenizer.current {
-        Code::Char('`')
+        Some('`')
             if tokenizer.parse_state.constructs.code_text
-                && (tokenizer.previous != Code::Char('`')
+                && (tokenizer.previous != Some('`')
                     || (len > 0
                         && tokenizer.events[len - 1].token_type == Token::CharacterEscape)) =>
         {
@@ -119,7 +119,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 ///     ^
 /// ```
 fn sequence_open(tokenizer: &mut Tokenizer, size: usize) -> State {
-    if let Code::Char('`') = tokenizer.current {
+    if let Some('`') = tokenizer.current {
         tokenizer.consume();
         State::Fn(Box::new(move |t| sequence_open(t, size + 1)))
     } else {
@@ -136,14 +136,14 @@ fn sequence_open(tokenizer: &mut Tokenizer, size: usize) -> State {
 /// ```
 fn between(tokenizer: &mut Tokenizer, size_open: usize) -> State {
     match tokenizer.current {
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None => State::Nok,
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
             State::Fn(Box::new(move |t| between(t, size_open)))
         }
-        Code::Char('`') => {
+        Some('`') => {
             tokenizer.enter(Token::CodeTextSequence);
             sequence_close(tokenizer, size_open, 0)
         }
@@ -162,7 +162,7 @@ fn between(tokenizer: &mut Tokenizer, size_open: usize) -> State {
 /// ```
 fn data(tokenizer: &mut Tokenizer, size_open: usize) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r' | '`') => {
+        None | Some('\n' | '`') => {
             tokenizer.exit(Token::CodeTextData);
             between(tokenizer, size_open)
         }
@@ -181,7 +181,7 @@ fn data(tokenizer: &mut Tokenizer, size_open: usize) -> State {
 /// ```
 fn sequence_close(tokenizer: &mut Tokenizer, size_open: usize, size: usize) -> State {
     match tokenizer.current {
-        Code::Char('`') => {
+        Some('`') => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| sequence_close(t, size_open, size + 1)))
         }
diff --git a/src/construct/definition.rs b/src/construct/definition.rs
index ffaaa98..f2b5ae0 100644
--- a/src/construct/definition.rs
+++ b/src/construct/definition.rs
@@ -100,7 +100,7 @@ use crate::construct::{
     partial_title::{start as title, Options as TitleOptions},
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 use crate::util::skip::opt_back as skip_opt_back;
 
 /// At the start of a definition.
@@ -137,7 +137,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('[') => tokenizer.go(
+        Some('[') => tokenizer.go(
             |t| {
                 label(
                     t,
@@ -162,7 +162,7 @@ fn before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn label_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(':') => {
+        Some(':') => {
             tokenizer.enter(Token::DefinitionMarker);
             tokenizer.consume();
             tokenizer.exit(Token::DefinitionMarker);
@@ -231,7 +231,7 @@ fn after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn after_whitespace(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::Definition);
             // You’d be interrupting.
             tokenizer.interrupt = true;
@@ -294,7 +294,7 @@ fn title_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn title_after_after_optional_whitespace(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => State::Ok,
+        None | Some('\n') => State::Ok,
         _ => State::Nok,
     }
 }
diff --git a/src/construct/hard_break_escape.rs b/src/construct/hard_break_escape.rs
index 40a83ef..0585c4c 100644
--- a/src/construct/hard_break_escape.rs
+++ b/src/construct/hard_break_escape.rs
@@ -40,7 +40,7 @@
 //! [html]: https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-br-element
 
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of a hard break (escape).
 ///
@@ -51,7 +51,7 @@ use crate::tokenizer::{Code, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('\\') if tokenizer.parse_state.constructs.hard_break_escape => {
+        Some('\\') if tokenizer.parse_state.constructs.hard_break_escape => {
             tokenizer.enter(Token::HardBreakEscape);
             tokenizer.consume();
             State::Fn(Box::new(inside))
@@ -69,7 +69,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.exit(Token::HardBreakEscape);
             State::Ok
         }
diff --git a/src/construct/heading_atx.rs b/src/construct/heading_atx.rs
index 5de9a80..7a7cf2e 100644
--- a/src/construct/heading_atx.rs
+++ b/src/construct/heading_atx.rs
@@ -57,7 +57,7 @@
 use super::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
 use crate::constant::{HEADING_ATX_OPENING_FENCE_SIZE_MAX, TAB_SIZE};
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, Event, EventType, State, Tokenizer};
+use crate::tokenizer::{ContentType, Event, EventType, State, Tokenizer};
 
 /// Start of a heading (atx).
 ///
@@ -87,7 +87,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 ///     ^
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
-    if Code::Char('#') == tokenizer.current {
+    if Some('#') == tokenizer.current {
         tokenizer.enter(Token::HeadingAtxSequence);
         sequence_open(tokenizer, 0)
     } else {
@@ -103,11 +103,11 @@ fn before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn sequence_open(tokenizer: &mut Tokenizer, rank: usize) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') if rank > 0 => {
+        None | Some('\n') if rank > 0 => {
             tokenizer.exit(Token::HeadingAtxSequence);
             at_break(tokenizer)
         }
-        Code::Char('#') if rank < HEADING_ATX_OPENING_FENCE_SIZE_MAX => {
+        Some('#') if rank < HEADING_ATX_OPENING_FENCE_SIZE_MAX => {
             tokenizer.consume();
             State::Fn(Box::new(move |tokenizer| {
                 sequence_open(tokenizer, rank + 1)
@@ -129,21 +129,19 @@ fn sequence_open(tokenizer: &mut Tokenizer, rank: usize) -> State {
 /// ```
 fn at_break(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::HeadingAtx);
             tokenizer.register_resolver("heading_atx".to_string(), Box::new(resolve));
             // Feel free to interrupt.
             tokenizer.interrupt = false;
             State::Ok
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
-            tokenizer.go(space_or_tab(), at_break)(tokenizer)
-        }
-        Code::Char('#') => {
+        Some('\t' | ' ') => tokenizer.go(space_or_tab(), at_break)(tokenizer),
+        Some('#') => {
             tokenizer.enter(Token::HeadingAtxSequence);
             further_sequence(tokenizer)
         }
-        Code::Char(_) => {
+        Some(_) => {
             tokenizer.enter_with_content(Token::Data, Some(ContentType::Text));
             data(tokenizer)
         }
@@ -159,7 +157,7 @@ fn at_break(tokenizer: &mut Tokenizer) -> State {
 ///           ^
 /// ```
 fn further_sequence(tokenizer: &mut Tokenizer) -> State {
-    if let Code::Char('#') = tokenizer.current {
+    if let Some('#') = tokenizer.current {
         tokenizer.consume();
         State::Fn(Box::new(further_sequence))
     } else {
@@ -177,7 +175,7 @@ fn further_sequence(tokenizer: &mut Tokenizer) -> State {
 fn data(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
         // Note: `#` for closing sequence must be preceded by whitespace, otherwise it’s just text.
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\t' | '\n' | '\r' | ' ') => {
+        None | Some('\t' | '\n' | ' ') => {
             tokenizer.exit(Token::Data);
             at_break(tokenizer)
         }
diff --git a/src/construct/heading_setext.rs b/src/construct/heading_setext.rs
index a0f7545..f9dd3f7 100644
--- a/src/construct/heading_setext.rs
+++ b/src/construct/heading_setext.rs
@@ -60,7 +60,7 @@
 use crate::constant::TAB_SIZE;
 use crate::construct::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
 use crate::token::Token;
-use crate::tokenizer::{Code, EventType, State, Tokenizer};
+use crate::tokenizer::{EventType, State, Tokenizer};
 use crate::util::skip::opt_back as skip_opt_back;
 
 /// Kind of underline.
@@ -148,7 +148,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == '-' || char == '=' => {
+        Some(char) if matches!(char, '-' | '=') => {
             tokenizer.enter(Token::HeadingSetextUnderline);
             inside(tokenizer, Kind::from_char(char))
         }
@@ -165,7 +165,7 @@ fn before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer, kind: Kind) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == kind.as_char() => {
+        Some(char) if char == kind.as_char() => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| inside(t, kind)))
         }
@@ -185,7 +185,7 @@ fn inside(tokenizer: &mut Tokenizer, kind: Kind) -> State {
 /// ```
 fn after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             // Feel free to interrupt.
             tokenizer.interrupt = false;
             tokenizer.register_resolver("heading_setext".to_string(), Box::new(resolve));
diff --git a/src/construct/html_flow.rs b/src/construct/html_flow.rs
index 24d6f98..238963d 100644
--- a/src/construct/html_flow.rs
+++ b/src/construct/html_flow.rs
@@ -105,8 +105,10 @@ use crate::construct::{
     partial_space_or_tab::{space_or_tab_with_options, Options as SpaceOrTabOptions},
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
-use crate::util::codes::{parse, serialize};
+use crate::tokenizer::{Point, State, Tokenizer};
+use crate::util::slice::{Position, Slice};
+
+const CDATA_SEARCH: [char; 6] = ['C', 'D', 'A', 'T', 'A', '['];
 
 /// Kind of HTML (flow).
 #[derive(Debug, PartialEq)]
@@ -168,17 +170,6 @@ impl QuoteKind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not `Code::Char('"' | '\'')`.
-    fn from_code(code: Code) -> QuoteKind {
-        match code {
-            Code::Char(char) => QuoteKind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// State needed to parse HTML (flow).
@@ -190,9 +181,9 @@ struct Info {
     start_tag: bool,
     /// Used depending on `kind` to either collect all parsed characters, or to
     /// store expected characters.
-    buffer: Vec<Code>,
-    /// `index` into `buffer` when expecting certain characters.
-    index: usize,
+    start: Option<Point>,
+    /// Collected index, for various reasons.
+    size: usize,
     /// Current quote, when in a double or single quoted attribute value.
     quote: Option<QuoteKind>,
 }
@@ -234,7 +225,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 ///     ^
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
-    if Code::Char('<') == tokenizer.current {
+    if Some('<') == tokenizer.current {
         tokenizer.enter(Token::HtmlFlowData);
         tokenizer.consume();
         State::Fn(Box::new(open))
@@ -259,21 +250,22 @@ fn open(tokenizer: &mut Tokenizer) -> State {
         kind: Kind::Basic,
         // Assume closing tag (or no tag).
         start_tag: false,
-        buffer: vec![],
-        index: 0,
+        start: None,
+        size: 0,
         quote: None,
     };
 
     match tokenizer.current {
-        Code::Char('!') => {
+        Some('!') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| declaration_open(t, info)))
         }
-        Code::Char('/') => {
+        Some('/') => {
             tokenizer.consume();
+            info.start = Some(tokenizer.point.clone());
             State::Fn(Box::new(|t| tag_close_start(t, info)))
         }
-        Code::Char('?') => {
+        Some('?') => {
             info.kind = Kind::Instruction;
             tokenizer.consume();
             // Do not form containers.
@@ -282,8 +274,9 @@ fn open(tokenizer: &mut Tokenizer) -> State {
             // right now, so we do need to search for `>`, similar to declarations.
             State::Fn(Box::new(|t| continuation_declaration_inside(t, info)))
         }
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             info.start_tag = true;
+            info.start = Some(tokenizer.point.clone());
             tag_name(tokenizer, info)
         }
         _ => State::Nok,
@@ -302,19 +295,18 @@ fn open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn declaration_open(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             info.kind = Kind::Comment;
             State::Fn(Box::new(|t| comment_open_inside(t, info)))
         }
-        Code::Char('[') => {
+        Some('[') => {
             tokenizer.consume();
             info.kind = Kind::Cdata;
-            info.buffer = parse("CDATA[");
-            info.index = 0;
+            info.size = 0;
             State::Fn(Box::new(|t| cdata_open_inside(t, info)))
         }
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             info.kind = Kind::Declaration;
             // Do not form containers.
@@ -333,7 +325,7 @@ fn declaration_open(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn comment_open_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             // Do not form containers.
             tokenizer.concrete = true;
@@ -350,20 +342,21 @@ fn comment_open_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
 ///        ^^^^^^
 /// ```
 fn cdata_open_inside(tokenizer: &mut Tokenizer, mut info: Info) -> State {
-    if tokenizer.current == info.buffer[info.index] {
-        info.index += 1;
-        tokenizer.consume();
+    match tokenizer.current {
+        Some(char) if char == CDATA_SEARCH[info.size] => {
+            info.size += 1;
+            tokenizer.consume();
 
-        if info.index == info.buffer.len() {
-            info.buffer.clear();
-            // Do not form containers.
-            tokenizer.concrete = true;
-            State::Fn(Box::new(|t| continuation(t, info)))
-        } else {
-            State::Fn(Box::new(|t| cdata_open_inside(t, info)))
+            if info.size == CDATA_SEARCH.len() {
+                info.size = 0;
+                // Do not form containers.
+                tokenizer.concrete = true;
+                State::Fn(Box::new(|t| continuation(t, info)))
+            } else {
+                State::Fn(Box::new(|t| cdata_open_inside(t, info)))
+            }
         }
-    } else {
-        State::Nok
+        _ => State::Nok,
     }
 }
 
@@ -373,11 +366,10 @@ fn cdata_open_inside(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// > | </x>
 ///       ^
 /// ```
-fn tag_close_start(tokenizer: &mut Tokenizer, mut info: Info) -> State {
+fn tag_close_start(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
-            info.buffer.push(tokenizer.current);
             State::Fn(Box::new(|t| tag_name(t, info)))
         }
         _ => State::Nok,
@@ -394,22 +386,27 @@ fn tag_close_start(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn tag_name(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::None
-        | Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ' | '/' | '>') => {
-            let tag_name_buffer = serialize(&info.buffer, false).to_lowercase();
-            let name = tag_name_buffer.as_str();
-            let slash = matches!(tokenizer.current, Code::Char('/'));
-
-            info.buffer.clear();
-
-            if !slash && info.start_tag && HTML_RAW_NAMES.contains(&name) {
+        None | Some('\t' | '\n' | ' ' | '/' | '>') => {
+            let slash = matches!(tokenizer.current, Some('/'));
+            let start = info.start.take().unwrap();
+            let name = Slice::from_position(
+                &tokenizer.parse_state.chars,
+                &Position {
+                    start: &start,
+                    end: &tokenizer.point,
+                },
+            )
+            .serialize()
+            .trim()
+            .to_lowercase();
+            println!("name: {:?}", name);
+
+            if !slash && info.start_tag && HTML_RAW_NAMES.contains(&name.as_str()) {
                 info.kind = Kind::Raw;
                 // Do not form containers.
                 tokenizer.concrete = true;
                 continuation(tokenizer, info)
-            } else if HTML_BLOCK_NAMES.contains(&name) {
+            } else if HTML_BLOCK_NAMES.contains(&name.as_str()) {
                 // Basic is assumed, no need to set `kind`.
                 if slash {
                     tokenizer.consume();
@@ -432,12 +429,11 @@ fn tag_name(tokenizer: &mut Tokenizer, mut info: Info) -> State {
                 }
             }
         }
-        Code::Char('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
+        Some('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
-            info.buffer.push(tokenizer.current);
             State::Fn(Box::new(|t| tag_name(t, info)))
         }
-        Code::Char(_) => State::Nok,
+        Some(_) => State::Nok,
     }
 }
 
@@ -449,7 +445,7 @@ fn tag_name(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn basic_self_closing(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.consume();
             // Do not form containers.
             tokenizer.concrete = true;
@@ -467,7 +463,7 @@ fn basic_self_closing(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn complete_closing_tag_after(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_closing_tag_after(t, info)))
         }
@@ -496,15 +492,15 @@ fn complete_closing_tag_after(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn complete_attribute_name_before(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('/') => {
+        Some('/') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_end(t, info)))
         }
-        Code::Char('0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
+        Some('0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_name(t, info)))
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_name_before(t, info)))
         }
@@ -524,7 +520,7 @@ fn complete_attribute_name_before(tokenizer: &mut Tokenizer, info: Info) -> Stat
 /// ```
 fn complete_attribute_name(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('-' | '.' | '0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
+        Some('-' | '.' | '0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_name(t, info)))
         }
@@ -543,11 +539,11 @@ fn complete_attribute_name(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn complete_attribute_name_after(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('=') => {
+        Some('=') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_value_before(t, info)))
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_name_after(t, info)))
         }
@@ -566,13 +562,13 @@ fn complete_attribute_name_after(tokenizer: &mut Tokenizer, info: Info) -> State
 /// ```
 fn complete_attribute_value_before(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('<' | '=' | '>' | '`') => State::Nok,
-        Code::Char('"' | '\'') => {
+        None | Some('<' | '=' | '>' | '`') => State::Nok,
+        Some(char) if matches!(char, '"' | '\'') => {
+            info.quote = Some(QuoteKind::from_char(char));
             tokenizer.consume();
-            info.quote = Some(QuoteKind::from_code(tokenizer.current));
             State::Fn(Box::new(|t| complete_attribute_value_quoted(t, info)))
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_value_before(t, info)))
         }
@@ -590,8 +586,8 @@ fn complete_attribute_value_before(tokenizer: &mut Tokenizer, mut info: Info) ->
 /// ```
 fn complete_attribute_value_quoted(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => State::Nok,
-        Code::Char(char) if char == info.quote.as_ref().unwrap().as_char() => {
+        None | Some('\n') => State::Nok,
+        Some(char) if char == info.quote.as_ref().unwrap().as_char() => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_value_quoted_after(t, info)))
         }
@@ -610,13 +606,10 @@ fn complete_attribute_value_quoted(tokenizer: &mut Tokenizer, info: Info) -> Sta
 /// ```
 fn complete_attribute_value_unquoted(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None
-        | Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ' | '"' | '\'' | '/' | '<' | '=' | '>' | '`') => {
+        None | Some('\t' | '\n' | ' ' | '"' | '\'' | '/' | '<' | '=' | '>' | '`') => {
             complete_attribute_name_after(tokenizer, info)
         }
-        Code::Char(_) => {
+        Some(_) => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_attribute_value_unquoted(t, info)))
         }
@@ -632,9 +625,7 @@ fn complete_attribute_value_unquoted(tokenizer: &mut Tokenizer, info: Info) -> S
 /// ```
 fn complete_attribute_value_quoted_after(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ' | '/' | '>') => {
-            complete_attribute_name_before(tokenizer, info)
-        }
+        Some('\t' | ' ' | '/' | '>') => complete_attribute_name_before(tokenizer, info),
         _ => State::Nok,
     }
 }
@@ -647,7 +638,7 @@ fn complete_attribute_value_quoted_after(tokenizer: &mut Tokenizer, info: Info)
 /// ```
 fn complete_end(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_after(t, info)))
         }
@@ -663,16 +654,16 @@ fn complete_end(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn complete_after(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             // Do not form containers.
             tokenizer.concrete = true;
             continuation(tokenizer, info)
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| complete_after(t, info)))
         }
-        Code::Char(_) => State::Nok,
+        Some(_) => State::Nok,
     }
 }
 
@@ -684,29 +675,27 @@ fn complete_after(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn continuation(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('-') if info.kind == Kind::Comment => {
+        Some('-') if info.kind == Kind::Comment => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_comment_inside(t, info)))
         }
-        Code::Char('<') if info.kind == Kind::Raw => {
+        Some('<') if info.kind == Kind::Raw => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_raw_tag_open(t, info)))
         }
-        Code::Char('>') if info.kind == Kind::Declaration => {
+        Some('>') if info.kind == Kind::Declaration => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_close(t, info)))
         }
-        Code::Char('?') if info.kind == Kind::Instruction => {
+        Some('?') if info.kind == Kind::Instruction => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_declaration_inside(t, info)))
         }
-        Code::Char(']') if info.kind == Kind::Cdata => {
+        Some(']') if info.kind == Kind::Cdata => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_character_data_inside(t, info)))
         }
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')
-            if info.kind == Kind::Basic || info.kind == Kind::Complete =>
-        {
+        Some('\n') if info.kind == Kind::Basic || info.kind == Kind::Complete => {
             tokenizer.exit(Token::HtmlFlowData);
             tokenizer.check(blank_line_before, |ok| {
                 if ok {
@@ -716,7 +705,7 @@ fn continuation(tokenizer: &mut Tokenizer, info: Info) -> State {
                 }
             })(tokenizer)
         }
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::HtmlFlowData);
             continuation_start(tokenizer, info)
         }
@@ -753,7 +742,7 @@ fn continuation_start(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn continuation_start_non_lazy(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
@@ -772,9 +761,7 @@ fn continuation_start_non_lazy(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn continuation_before(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            continuation_start(tokenizer, info)
-        }
+        None | Some('\n') => continuation_start(tokenizer, info),
         _ => {
             tokenizer.enter(Token::HtmlFlowData);
             continuation(tokenizer, info)
@@ -790,7 +777,7 @@ fn continuation_before(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn continuation_comment_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_declaration_inside(t, info)))
         }
@@ -804,10 +791,11 @@ fn continuation_comment_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// > | <script>console.log(1)</script>
 ///                            ^
 /// ```
-fn continuation_raw_tag_open(tokenizer: &mut Tokenizer, info: Info) -> State {
+fn continuation_raw_tag_open(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char('/') => {
+        Some('/') => {
             tokenizer.consume();
+            info.start = Some(tokenizer.point.clone());
             State::Fn(Box::new(|t| continuation_raw_end_tag(t, info)))
         }
         _ => continuation(tokenizer, info),
@@ -822,24 +810,34 @@ fn continuation_raw_tag_open(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn continuation_raw_end_tag(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
-            let tag_name_buffer = serialize(&info.buffer, false).to_lowercase();
-            info.buffer.clear();
-
-            if HTML_RAW_NAMES.contains(&tag_name_buffer.as_str()) {
+        Some('>') => {
+            info.size = 0;
+
+            let start = info.start.take().unwrap();
+            let name = Slice::from_position(
+                &tokenizer.parse_state.chars,
+                &Position {
+                    start: &start,
+                    end: &tokenizer.point,
+                },
+            )
+            .serialize()
+            .to_lowercase();
+
+            if HTML_RAW_NAMES.contains(&name.as_str()) {
                 tokenizer.consume();
                 State::Fn(Box::new(|t| continuation_close(t, info)))
             } else {
                 continuation(tokenizer, info)
             }
         }
-        Code::Char('A'..='Z' | 'a'..='z') if info.buffer.len() < HTML_RAW_SIZE_MAX => {
+        Some('A'..='Z' | 'a'..='z') if info.size < HTML_RAW_SIZE_MAX => {
             tokenizer.consume();
-            info.buffer.push(tokenizer.current);
+            info.size += 1;
             State::Fn(Box::new(|t| continuation_raw_end_tag(t, info)))
         }
         _ => {
-            info.buffer.clear();
+            info.size = 0;
             continuation(tokenizer, info)
         }
     }
@@ -853,7 +851,7 @@ fn continuation_raw_end_tag(tokenizer: &mut Tokenizer, mut info: Info) -> State
 /// ```
 fn continuation_character_data_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char(']') => {
+        Some(']') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_declaration_inside(t, info)))
         }
@@ -877,11 +875,11 @@ fn continuation_character_data_inside(tokenizer: &mut Tokenizer, info: Info) ->
 /// ```
 fn continuation_declaration_inside(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_close(t, info)))
         }
-        Code::Char('-') if info.kind == Kind::Comment => {
+        Some('-') if info.kind == Kind::Comment => {
             tokenizer.consume();
             State::Fn(Box::new(|t| continuation_declaration_inside(t, info)))
         }
@@ -897,7 +895,7 @@ fn continuation_declaration_inside(tokenizer: &mut Tokenizer, info: Info) -> Sta
 /// ```
 fn continuation_close(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::HtmlFlowData);
             continuation_after(tokenizer)
         }
diff --git a/src/construct/html_text.rs b/src/construct/html_text.rs
index 3ac8d71..b1ad113 100644
--- a/src/construct/html_text.rs
+++ b/src/construct/html_text.rs
@@ -56,8 +56,9 @@
 
 use crate::construct::partial_space_or_tab::space_or_tab;
 use crate::token::Token;
-use crate::tokenizer::{Code, State, StateFn, Tokenizer};
-use crate::util::codes::parse;
+use crate::tokenizer::{State, StateFn, Tokenizer};
+
+const CDATA_SEARCH: [char; 6] = ['C', 'D', 'A', 'T', 'A', '['];
 
 /// Start of HTML (text)
 ///
@@ -66,7 +67,7 @@ use crate::util::codes::parse;
 ///       ^
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
-    if Code::Char('<') == tokenizer.current && tokenizer.parse_state.constructs.html_text {
+    if Some('<') == tokenizer.current && tokenizer.parse_state.constructs.html_text {
         tokenizer.enter(Token::HtmlText);
         tokenizer.enter(Token::HtmlTextData);
         tokenizer.consume();
@@ -88,19 +89,19 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('!') => {
+        Some('!') => {
             tokenizer.consume();
             State::Fn(Box::new(declaration_open))
         }
-        Code::Char('/') => {
+        Some('/') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_close_start))
         }
-        Code::Char('?') => {
+        Some('?') => {
             tokenizer.consume();
             State::Fn(Box::new(instruction))
         }
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open))
         }
@@ -120,16 +121,15 @@ fn open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn declaration_open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(comment_open_inside))
         }
-        Code::Char('[') => {
+        Some('[') => {
             tokenizer.consume();
-            let buffer = parse("CDATA[");
-            State::Fn(Box::new(|t| cdata_open_inside(t, buffer, 0)))
+            State::Fn(Box::new(|t| cdata_open_inside(t, 0)))
         }
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(declaration))
         }
@@ -145,7 +145,7 @@ fn declaration_open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn comment_open_inside(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(comment_start))
         }
@@ -168,8 +168,8 @@ fn comment_open_inside(tokenizer: &mut Tokenizer) -> State {
 /// [html_flow]: crate::construct::html_flow
 fn comment_start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('>') => State::Nok,
-        Code::Char('-') => {
+        None | Some('>') => State::Nok,
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(comment_start_dash))
         }
@@ -192,7 +192,7 @@ fn comment_start(tokenizer: &mut Tokenizer) -> State {
 /// [html_flow]: crate::construct::html_flow
 fn comment_start_dash(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('>') => State::Nok,
+        None | Some('>') => State::Nok,
         _ => comment(tokenizer),
     }
 }
@@ -205,11 +205,9 @@ fn comment_start_dash(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn comment(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(comment))
-        }
-        Code::Char('-') => {
+        None => State::Nok,
+        Some('\n') => at_line_ending(tokenizer, Box::new(comment)),
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(comment_close))
         }
@@ -228,7 +226,7 @@ fn comment(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn comment_close(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-') => {
+        Some('-') => {
             tokenizer.consume();
             State::Fn(Box::new(end))
         }
@@ -242,17 +240,18 @@ fn comment_close(tokenizer: &mut Tokenizer) -> State {
 /// > | a <![CDATA[>&<]]> b
 ///          ^^^^^^
 /// ```
-fn cdata_open_inside(tokenizer: &mut Tokenizer, buffer: Vec<Code>, index: usize) -> State {
-    if tokenizer.current == buffer[index] {
-        tokenizer.consume();
+fn cdata_open_inside(tokenizer: &mut Tokenizer, index: usize) -> State {
+    match tokenizer.current {
+        Some(char) if char == CDATA_SEARCH[index] => {
+            tokenizer.consume();
 
-        if index + 1 == buffer.len() {
-            State::Fn(Box::new(cdata))
-        } else {
-            State::Fn(Box::new(move |t| cdata_open_inside(t, buffer, index + 1)))
+            if index + 1 == CDATA_SEARCH.len() {
+                State::Fn(Box::new(cdata))
+            } else {
+                State::Fn(Box::new(move |t| cdata_open_inside(t, index + 1)))
+            }
         }
-    } else {
-        State::Nok
+        _ => State::Nok,
     }
 }
 
@@ -264,11 +263,9 @@ fn cdata_open_inside(tokenizer: &mut Tokenizer, buffer: Vec<Code>, index: usize)
 /// ```
 fn cdata(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(cdata))
-        }
-        Code::Char(']') => {
+        None => State::Nok,
+        Some('\n') => at_line_ending(tokenizer, Box::new(cdata)),
+        Some(']') => {
             tokenizer.consume();
             State::Fn(Box::new(cdata_close))
         }
@@ -287,7 +284,7 @@ fn cdata(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn cdata_close(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(']') => {
+        Some(']') => {
             tokenizer.consume();
             State::Fn(Box::new(cdata_end))
         }
@@ -303,8 +300,8 @@ fn cdata_close(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn cdata_end(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => end(tokenizer),
-        Code::Char(']') => cdata_close(tokenizer),
+        Some('>') => end(tokenizer),
+        Some(']') => cdata_close(tokenizer),
         _ => cdata(tokenizer),
     }
 }
@@ -317,10 +314,8 @@ fn cdata_end(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn declaration(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('>') => end(tokenizer),
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(declaration))
-        }
+        None | Some('>') => end(tokenizer),
+        Some('\n') => at_line_ending(tokenizer, Box::new(declaration)),
         _ => {
             tokenizer.consume();
             State::Fn(Box::new(declaration))
@@ -336,11 +331,9 @@ fn declaration(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn instruction(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(instruction))
-        }
-        Code::Char('?') => {
+        None => State::Nok,
+        Some('\n') => at_line_ending(tokenizer, Box::new(instruction)),
+        Some('?') => {
             tokenizer.consume();
             State::Fn(Box::new(instruction_close))
         }
@@ -359,7 +352,7 @@ fn instruction(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn instruction_close(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => end(tokenizer),
+        Some('>') => end(tokenizer),
         _ => instruction(tokenizer),
     }
 }
@@ -372,7 +365,7 @@ fn instruction_close(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_close_start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('A'..='Z' | 'a'..='z') => {
+        Some('A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_close))
         }
@@ -388,7 +381,7 @@ fn tag_close_start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_close(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
+        Some('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_close))
         }
@@ -404,10 +397,8 @@ fn tag_close(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_close_between(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(tag_close_between))
-        }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\n') => at_line_ending(tokenizer, Box::new(tag_close_between)),
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_close_between))
         }
@@ -423,13 +414,11 @@ fn tag_close_between(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
+        Some('-' | '0'..='9' | 'A'..='Z' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open))
         }
-        Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ' | '/' | '>') => tag_open_between(tokenizer),
+        Some('\t' | '\n' | ' ' | '/' | '>') => tag_open_between(tokenizer),
         _ => State::Nok,
     }
 }
@@ -442,18 +431,16 @@ fn tag_open(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_between(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(tag_open_between))
-        }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\n') => at_line_ending(tokenizer, Box::new(tag_open_between)),
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_between))
         }
-        Code::Char('/') => {
+        Some('/') => {
             tokenizer.consume();
             State::Fn(Box::new(end))
         }
-        Code::Char(':' | 'A'..='Z' | '_' | 'a'..='z') => {
+        Some(':' | 'A'..='Z' | '_' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_name))
         }
@@ -469,7 +456,7 @@ fn tag_open_between(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_attribute_name(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('-' | '.' | '0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
+        Some('-' | '.' | '0'..='9' | ':' | 'A'..='Z' | '_' | 'a'..='z') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_name))
         }
@@ -486,14 +473,12 @@ fn tag_open_attribute_name(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_attribute_name_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(tag_open_attribute_name_after))
-        }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\n') => at_line_ending(tokenizer, Box::new(tag_open_attribute_name_after)),
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_name_after))
         }
-        Code::Char('=') => {
+        Some('=') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_value_before))
         }
@@ -510,19 +495,17 @@ fn tag_open_attribute_name_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_attribute_value_before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('<' | '=' | '>' | '`') => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
-            at_line_ending(tokenizer, Box::new(tag_open_attribute_value_before))
-        }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        None | Some('<' | '=' | '>' | '`') => State::Nok,
+        Some('\n') => at_line_ending(tokenizer, Box::new(tag_open_attribute_value_before)),
+        Some('\t' | ' ') => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_value_before))
         }
-        Code::Char(char) if char == '"' || char == '\'' => {
+        Some(char) if char == '"' || char == '\'' => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| tag_open_attribute_value_quoted(t, char)))
         }
-        Code::Char(_) => {
+        Some(_) => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_value_unquoted))
         }
@@ -537,12 +520,12 @@ fn tag_open_attribute_value_before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_attribute_value_quoted(tokenizer: &mut Tokenizer, marker: char) -> State {
     match tokenizer.current {
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => at_line_ending(
+        None => State::Nok,
+        Some('\n') => at_line_ending(
             tokenizer,
             Box::new(move |t| tag_open_attribute_value_quoted(t, marker)),
         ),
-        Code::Char(char) if char == marker => {
+        Some(char) if char == marker => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_value_quoted_after))
         }
@@ -563,11 +546,9 @@ fn tag_open_attribute_value_quoted(tokenizer: &mut Tokenizer, marker: char) -> S
 /// ```
 fn tag_open_attribute_value_unquoted(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('"' | '\'' | '<' | '=' | '`') => State::Nok,
-        Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ' | '/' | '>') => tag_open_between(tokenizer),
-        Code::Char(_) => {
+        None | Some('"' | '\'' | '<' | '=' | '`') => State::Nok,
+        Some('\t' | '\n' | ' ' | '/' | '>') => tag_open_between(tokenizer),
+        Some(_) => {
             tokenizer.consume();
             State::Fn(Box::new(tag_open_attribute_value_unquoted))
         }
@@ -583,9 +564,7 @@ fn tag_open_attribute_value_unquoted(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn tag_open_attribute_value_quoted_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ' | '>' | '/') => tag_open_between(tokenizer),
+        Some('\t' | '\n' | ' ' | '>' | '/') => tag_open_between(tokenizer),
         _ => State::Nok,
     }
 }
@@ -598,7 +577,7 @@ fn tag_open_attribute_value_quoted_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn end(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.consume();
             tokenizer.exit(Token::HtmlTextData);
             tokenizer.exit(Token::HtmlText);
@@ -620,7 +599,7 @@ fn end(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn at_line_ending(tokenizer: &mut Tokenizer, return_state: Box<StateFn>) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.exit(Token::HtmlTextData);
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
diff --git a/src/construct/label_end.rs b/src/construct/label_end.rs
index 6f0a707..5ea788f 100644
--- a/src/construct/label_end.rs
+++ b/src/construct/label_end.rs
@@ -1,4 +1,4 @@
-//! Label end is a construct that occurs in the [text][] content type.
+//! Label end is a construct that occurs in the [text][] conten&t type.
 //!
 //! It forms with the following BNF:
 //!
@@ -154,10 +154,11 @@ use crate::construct::{
     partial_title::{start as title, Options as TitleOptions},
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, Event, EventType, Media, State, Tokenizer};
+use crate::tokenizer::{Event, EventType, Media, State, Tokenizer};
 use crate::util::{
     normalize_identifier::normalize_identifier,
-    span::{serialize, Span},
+    skip,
+    slice::{Position, Slice},
 };
 
 /// State needed to parse label end.
@@ -181,7 +182,7 @@ struct Info {
 /// > | [a] b
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
-    if Code::Char(']') == tokenizer.current && tokenizer.parse_state.constructs.label_end {
+    if Some(']') == tokenizer.current && tokenizer.parse_state.constructs.label_end {
         let mut label_start_index = None;
         let mut index = tokenizer.label_start_stack.len();
 
@@ -207,19 +208,23 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
             }
 
             let label_end_start = tokenizer.events.len();
+
             let info = Info {
                 label_start_index,
                 media: Media {
                     start: label_start.start,
                     end: (label_end_start, label_end_start + 3),
-                    id: normalize_identifier(&serialize(
-                        &tokenizer.parse_state.codes,
-                        &Span {
-                            start_index: tokenizer.events[label_start.start.1].point.index,
-                            end_index: tokenizer.events[label_end_start - 1].point.index,
-                        },
-                        false,
-                    )),
+                    // To do: virtual spaces not needed, create a `to_str`?
+                    id: normalize_identifier(
+                        &Slice::from_position(
+                            &tokenizer.parse_state.chars,
+                            &Position {
+                                start: &tokenizer.events[label_start.start.1].point,
+                                end: &tokenizer.events[label_end_start - 1].point,
+                            },
+                        )
+                        .serialize(),
+                    ),
                 },
             };
 
@@ -253,7 +258,7 @@ fn after(tokenizer: &mut Tokenizer, info: Info) -> State {
 
     match tokenizer.current {
         // Resource (`[asd](fgh)`)?
-        Code::Char('(') => tokenizer.attempt(resource, move |is_ok| {
+        Some('(') => tokenizer.attempt(resource, move |is_ok| {
             Box::new(move |t| {
                 // Also fine if `defined`, as then it’s a valid shortcut.
                 if is_ok || defined {
@@ -264,7 +269,7 @@ fn after(tokenizer: &mut Tokenizer, info: Info) -> State {
             })
         })(tokenizer),
         // Full (`[asd][fgh]`) or collapsed (`[asd][]`) reference?
-        Code::Char('[') => tokenizer.attempt(full_reference, move |is_ok| {
+        Some('[') => tokenizer.attempt(full_reference, move |is_ok| {
             Box::new(move |t| {
                 if is_ok {
                     ok(t, info)
@@ -377,7 +382,7 @@ fn nok(tokenizer: &mut Tokenizer, label_start_index: usize) -> State {
 /// ```
 fn resource(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('(') => {
+        Some('(') => {
             tokenizer.enter(Token::Resource);
             tokenizer.enter(Token::ResourceMarker);
             tokenizer.consume();
@@ -406,7 +411,7 @@ fn resource_start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn resource_open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(')') => resource_end(tokenizer),
+        Some(')') => resource_end(tokenizer),
         _ => tokenizer.go(
             |t| {
                 destination(
@@ -446,7 +451,7 @@ fn destination_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn resource_between(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('"' | '\'' | '(') => tokenizer.go(
+        Some('"' | '\'' | '(') => tokenizer.go(
             |t| {
                 title(
                     t,
@@ -481,7 +486,7 @@ fn title_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn resource_end(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(')') => {
+        Some(')') => {
             tokenizer.enter(Token::ResourceMarker);
             tokenizer.consume();
             tokenizer.exit(Token::ResourceMarker);
@@ -500,7 +505,7 @@ fn resource_end(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn full_reference(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('[') => tokenizer.go(
+        Some('[') => tokenizer.go(
             |t| {
                 label(
                     t,
@@ -524,36 +529,23 @@ fn full_reference(tokenizer: &mut Tokenizer) -> State {
 ///          ^
 /// ```
 fn full_reference_after(tokenizer: &mut Tokenizer) -> State {
-    let events = &tokenizer.events;
-    let mut index = events.len() - 1;
-    let mut start: Option<usize> = None;
-    let mut end: Option<usize> = None;
-
-    while index > 0 {
-        index -= 1;
-        let event = &events[index];
-        if event.token_type == Token::ReferenceString {
-            if event.event_type == EventType::Exit {
-                end = Some(event.point.index);
-            } else {
-                start = Some(event.point.index);
-                break;
-            }
-        }
-    }
+    let end = skip::to_back(
+        &tokenizer.events,
+        tokenizer.events.len() - 1,
+        &[Token::ReferenceString],
+    );
+
+    // To do: virtual spaces not needed, create a `to_str`?
+    let id = Slice::from_position(
+        &tokenizer.parse_state.chars,
+        &Position::from_exit_event(&tokenizer.events, end),
+    )
+    .serialize();
 
     if tokenizer
         .parse_state
         .definitions
-        .contains(&normalize_identifier(&serialize(
-            &tokenizer.parse_state.codes,
-            &Span {
-                // Always found, otherwise we don’t get here.
-                start_index: start.unwrap(),
-                end_index: end.unwrap(),
-            },
-            false,
-        )))
+        .contains(&normalize_identifier(&id))
     {
         State::Ok
     } else {
@@ -571,7 +563,7 @@ fn full_reference_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn collapsed_reference(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('[') => {
+        Some('[') => {
             tokenizer.enter(Token::Reference);
             tokenizer.enter(Token::ReferenceMarker);
             tokenizer.consume();
@@ -592,7 +584,7 @@ fn collapsed_reference(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn collapsed_reference_open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char(']') => {
+        Some(']') => {
             tokenizer.enter(Token::ReferenceMarker);
             tokenizer.consume();
             tokenizer.exit(Token::ReferenceMarker);
@@ -735,7 +727,11 @@ pub fn resolve_media(tokenizer: &mut Tokenizer) {
             0,
             vec![Event {
                 event_type: EventType::Exit,
-                token_type: Token::Link,
+                token_type: if group_enter_event.token_type == Token::LabelLink {
+                    Token::Link
+                } else {
+                    Token::Image
+                },
                 point: events[group_end_index].point.clone(),
                 link: None,
             }],
diff --git a/src/construct/label_start_image.rs b/src/construct/label_start_image.rs
index 8c12ffe..078026d 100644
--- a/src/construct/label_start_image.rs
+++ b/src/construct/label_start_image.rs
@@ -30,7 +30,7 @@
 
 use super::label_end::resolve_media;
 use crate::token::Token;
-use crate::tokenizer::{Code, LabelStart, State, Tokenizer};
+use crate::tokenizer::{LabelStart, State, Tokenizer};
 
 /// Start of label (image) start.
 ///
@@ -40,7 +40,7 @@ use crate::tokenizer::{Code, LabelStart, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('!') if tokenizer.parse_state.constructs.label_start_image => {
+        Some('!') if tokenizer.parse_state.constructs.label_start_image => {
             tokenizer.enter(Token::LabelImage);
             tokenizer.enter(Token::LabelImageMarker);
             tokenizer.consume();
@@ -59,7 +59,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 pub fn open(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('[') => {
+        Some('[') => {
             tokenizer.enter(Token::LabelMarker);
             tokenizer.consume();
             tokenizer.exit(Token::LabelMarker);
diff --git a/src/construct/label_start_link.rs b/src/construct/label_start_link.rs
index e13cd77..d7ae1d6 100644
--- a/src/construct/label_start_link.rs
+++ b/src/construct/label_start_link.rs
@@ -29,7 +29,7 @@
 
 use super::label_end::resolve_media;
 use crate::token::Token;
-use crate::tokenizer::{Code, LabelStart, State, Tokenizer};
+use crate::tokenizer::{LabelStart, State, Tokenizer};
 
 /// Start of label (link) start.
 ///
@@ -39,7 +39,7 @@ use crate::tokenizer::{Code, LabelStart, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('[') if tokenizer.parse_state.constructs.label_start_link => {
+        Some('[') if tokenizer.parse_state.constructs.label_start_link => {
             let start = tokenizer.events.len();
             tokenizer.enter(Token::LabelLink);
             tokenizer.enter(Token::LabelMarker);
diff --git a/src/construct/list.rs b/src/construct/list.rs
index f5bb0ce..355eeee 100644
--- a/src/construct/list.rs
+++ b/src/construct/list.rs
@@ -50,10 +50,10 @@ use crate::construct::{
     thematic_break::start as thematic_break,
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, EventType, State, Tokenizer};
+use crate::tokenizer::{EventType, State, Tokenizer};
 use crate::util::{
     skip,
-    span::{codes as codes_from_span, from_exit_event},
+    slice::{Position, Slice},
 };
 
 /// Type of list.
@@ -117,17 +117,6 @@ impl Kind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not `Code::Char('.' | ')' | '*' | '+' | '-')`.
-    fn from_code(code: Code) -> Kind {
-        match code {
-            Code::Char(char) => Kind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// Start of list item.
@@ -160,11 +149,11 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
         // Unordered.
-        Code::Char('*' | '+' | '-') => tokenizer.check(thematic_break, |ok| {
+        Some('*' | '+' | '-') => tokenizer.check(thematic_break, |ok| {
             Box::new(if ok { nok } else { before_unordered })
         })(tokenizer),
         // Ordered.
-        Code::Char(char) if char.is_ascii_digit() && (!tokenizer.interrupt || char == '1') => {
+        Some(char) if char.is_ascii_digit() && (!tokenizer.interrupt || char == '1') => {
             tokenizer.enter(Token::ListItemPrefix);
             tokenizer.enter(Token::ListItemValue);
             inside(tokenizer, 0)
@@ -194,11 +183,11 @@ fn before_unordered(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer, size: usize) -> State {
     match tokenizer.current {
-        Code::Char(char) if char.is_ascii_digit() && size + 1 < LIST_ITEM_VALUE_SIZE_MAX => {
+        Some(char) if char.is_ascii_digit() && size + 1 < LIST_ITEM_VALUE_SIZE_MAX => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| inside(t, size + 1)))
         }
-        Code::Char('.' | ')') if !tokenizer.interrupt || size < 2 => {
+        Some('.' | ')') if !tokenizer.interrupt || size < 2 => {
             tokenizer.exit(Token::ListItemValue);
             marker(tokenizer)
         }
@@ -273,10 +262,7 @@ fn whitespace(tokenizer: &mut Tokenizer) -> State {
 ///      ^
 /// ```
 fn whitespace_after(tokenizer: &mut Tokenizer) -> State {
-    if matches!(
-        tokenizer.current,
-        Code::VirtualSpace | Code::Char('\t' | ' ')
-    ) {
+    if matches!(tokenizer.current, Some('\t' | ' ')) {
         State::Nok
     } else {
         State::Ok
@@ -291,7 +277,7 @@ fn whitespace_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn prefix_other(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.enter(Token::SpaceOrTab);
             tokenizer.consume();
             tokenizer.exit(Token::SpaceOrTab);
@@ -316,8 +302,18 @@ fn after(tokenizer: &mut Tokenizer, blank: bool) -> State {
             tokenizer.events.len() - 1,
             &[Token::ListItem],
         );
-        let prefix = tokenizer.point.index - tokenizer.events[start].point.index
-            + (if blank { 1 } else { 0 });
+        let mut prefix = Slice::from_position(
+            &tokenizer.parse_state.chars,
+            &Position {
+                start: &tokenizer.events[start].point,
+                end: &tokenizer.point,
+            },
+        )
+        .size();
+
+        if blank {
+            prefix += 1;
+        }
 
         let container = tokenizer.container.as_mut().unwrap();
         container.blank_initial = blank;
@@ -403,12 +399,15 @@ pub fn resolve_list_item(tokenizer: &mut Tokenizer) {
         if event.token_type == Token::ListItem {
             if event.event_type == EventType::Enter {
                 let end = skip::opt(&tokenizer.events, index, &[Token::ListItem]) - 1;
-                let marker = skip::to(&tokenizer.events, index, &[Token::ListItemMarker]) + 1;
-                let codes = codes_from_span(
-                    &tokenizer.parse_state.codes,
-                    &from_exit_event(&tokenizer.events, marker),
+                let marker = skip::to(&tokenizer.events, index, &[Token::ListItemMarker]);
+                let kind = Kind::from_char(
+                    Slice::from_point(
+                        &tokenizer.parse_state.chars,
+                        &tokenizer.events[marker].point,
+                    )
+                    .head()
+                    .unwrap(),
                 );
-                let kind = Kind::from_code(codes[0]);
                 let current = (kind, balance, index, end);
 
                 let mut list_index = lists_wip.len();
diff --git a/src/construct/paragraph.rs b/src/construct/paragraph.rs
index 4bce6a4..5d230d3 100644
--- a/src/construct/paragraph.rs
+++ b/src/construct/paragraph.rs
@@ -33,7 +33,7 @@
 //! [html]: https://html.spec.whatwg.org/multipage/grouping-content.html#the-p-element
 
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, EventType, State, Tokenizer};
+use crate::tokenizer::{ContentType, EventType, State, Tokenizer};
 use crate::util::skip::opt as skip_opt;
 
 /// Before a paragraph.
@@ -44,7 +44,7 @@ use crate::util::skip::opt as skip_opt;
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             unreachable!("unexpected eol/eof")
         }
         _ => {
@@ -63,7 +63,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::Data);
             tokenizer.exit(Token::Paragraph);
             tokenizer.register_resolver_before("paragraph".to_string(), Box::new(resolve));
diff --git a/src/construct/partial_data.rs b/src/construct/partial_data.rs
index 4216276..0b66b09 100644
--- a/src/construct/partial_data.rs
+++ b/src/construct/partial_data.rs
@@ -7,7 +7,7 @@
 //! [text]: crate::content::text
 
 use crate::token::Token;
-use crate::tokenizer::{Code, EventType, State, Tokenizer};
+use crate::tokenizer::{EventType, State, Tokenizer};
 
 /// At the beginning of data.
 ///
@@ -15,13 +15,14 @@ use crate::tokenizer::{Code, EventType, State, Tokenizer};
 /// > | abc
 ///     ^
 /// ```
-pub fn start(tokenizer: &mut Tokenizer, stop: &'static [Code]) -> State {
-    if stop.contains(&tokenizer.current) {
-        tokenizer.enter(Token::Data);
-        tokenizer.consume();
-        State::Fn(Box::new(move |t| data(t, stop)))
-    } else {
-        at_break(tokenizer, stop)
+pub fn start(tokenizer: &mut Tokenizer, stop: &'static [char]) -> State {
+    match tokenizer.current {
+        Some(char) if stop.contains(&char) => {
+            tokenizer.enter(Token::Data);
+            tokenizer.consume();
+            State::Fn(Box::new(move |t| data(t, stop)))
+        }
+        _ => at_break(tokenizer, stop),
     }
 }
 
@@ -31,16 +32,16 @@ pub fn start(tokenizer: &mut Tokenizer, stop: &'static [Code]) -> State {
 /// > | abc
 ///     ^
 /// ```
-fn at_break(tokenizer: &mut Tokenizer, stop: &'static [Code]) -> State {
+fn at_break(tokenizer: &mut Tokenizer, stop: &'static [char]) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None => State::Ok,
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
             State::Fn(Box::new(move |t| at_break(t, stop)))
         }
-        _ if stop.contains(&tokenizer.current) => {
+        Some(char) if stop.contains(&char) => {
             tokenizer.register_resolver_before("data".to_string(), Box::new(resolve_data));
             State::Ok
         }
@@ -57,10 +58,10 @@ fn at_break(tokenizer: &mut Tokenizer, stop: &'static [Code]) -> State {
 /// > | abc
 ///     ^^^
 /// ```
-fn data(tokenizer: &mut Tokenizer, stop: &'static [Code]) -> State {
+fn data(tokenizer: &mut Tokenizer, stop: &'static [char]) -> State {
     let done = match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => true,
-        _ if stop.contains(&tokenizer.current) => true,
+        None | Some('\n') => true,
+        Some(char) if stop.contains(&char) => true,
         _ => false,
     };
 
diff --git a/src/construct/partial_destination.rs b/src/construct/partial_destination.rs
index 6a984e2..6447228 100644
--- a/src/construct/partial_destination.rs
+++ b/src/construct/partial_destination.rs
@@ -72,7 +72,7 @@
 //! [sanitize_uri]: crate::util::sanitize_uri
 
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, State, Tokenizer};
+use crate::tokenizer::{ContentType, State, Tokenizer};
 
 /// Configuration.
 ///
@@ -117,7 +117,7 @@ pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
     };
 
     match tokenizer.current {
-        Code::Char('<') => {
+        Some('<') => {
             tokenizer.enter(info.options.destination.clone());
             tokenizer.enter(info.options.literal.clone());
             tokenizer.enter(info.options.marker.clone());
@@ -125,11 +125,9 @@ pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
             tokenizer.exit(info.options.marker.clone());
             State::Fn(Box::new(|t| enclosed_before(t, info)))
         }
-        Code::None | Code::CarriageReturnLineFeed | Code::VirtualSpace | Code::Char(' ' | ')') => {
-            State::Nok
-        }
-        Code::Char(char) if char.is_ascii_control() => State::Nok,
-        Code::Char(_) => {
+        None | Some(' ' | ')') => State::Nok,
+        Some(char) if char.is_ascii_control() => State::Nok,
+        Some(_) => {
             tokenizer.enter(info.options.destination.clone());
             tokenizer.enter(info.options.raw.clone());
             tokenizer.enter(info.options.string.clone());
@@ -146,7 +144,7 @@ pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
 ///      ^
 /// ```
 fn enclosed_before(tokenizer: &mut Tokenizer, info: Info) -> State {
-    if let Code::Char('>') = tokenizer.current {
+    if let Some('>') = tokenizer.current {
         tokenizer.enter(info.options.marker.clone());
         tokenizer.consume();
         tokenizer.exit(info.options.marker.clone());
@@ -168,13 +166,13 @@ fn enclosed_before(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn enclosed(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('>') => {
+        Some('>') => {
             tokenizer.exit(Token::Data);
             tokenizer.exit(info.options.string.clone());
             enclosed_before(tokenizer, info)
         }
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r' | '<') => State::Nok,
-        Code::Char('\\') => {
+        None | Some('\n' | '<') => State::Nok,
+        Some('\\') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| enclosed_escape(t, info)))
         }
@@ -193,7 +191,7 @@ fn enclosed(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn enclosed_escape(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('<' | '>' | '\\') => {
+        Some('<' | '>' | '\\') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| enclosed(t, info)))
         }
@@ -209,7 +207,7 @@ fn enclosed_escape(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn raw(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char('(') => {
+        Some('(') => {
             if info.balance >= info.options.limit {
                 State::Nok
             } else {
@@ -218,7 +216,7 @@ fn raw(tokenizer: &mut Tokenizer, mut info: Info) -> State {
                 State::Fn(Box::new(move |t| raw(t, info)))
             }
         }
-        Code::Char(')') => {
+        Some(')') => {
             if info.balance == 0 {
                 tokenizer.exit(Token::Data);
                 tokenizer.exit(info.options.string.clone());
@@ -231,10 +229,7 @@ fn raw(tokenizer: &mut Tokenizer, mut info: Info) -> State {
                 State::Fn(Box::new(move |t| raw(t, info)))
             }
         }
-        Code::None
-        | Code::CarriageReturnLineFeed
-        | Code::VirtualSpace
-        | Code::Char('\t' | '\n' | '\r' | ' ') => {
+        None | Some('\t' | '\n' | ' ') => {
             if info.balance > 0 {
                 State::Nok
             } else {
@@ -245,12 +240,12 @@ fn raw(tokenizer: &mut Tokenizer, mut info: Info) -> State {
                 State::Ok
             }
         }
-        Code::Char(char) if char.is_ascii_control() => State::Nok,
-        Code::Char('\\') => {
+        Some(char) if char.is_ascii_control() => State::Nok,
+        Some('\\') => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| raw_escape(t, info)))
         }
-        Code::Char(_) => {
+        Some(_) => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| raw(t, info)))
         }
@@ -265,7 +260,7 @@ fn raw(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn raw_escape(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char('(' | ')' | '\\') => {
+        Some('(' | ')' | '\\') => {
             tokenizer.consume();
             State::Fn(Box::new(move |t| raw(t, info)))
         }
diff --git a/src/construct/partial_label.rs b/src/construct/partial_label.rs
index 91a0e26..ee31533 100644
--- a/src/construct/partial_label.rs
+++ b/src/construct/partial_label.rs
@@ -62,7 +62,7 @@ use super::partial_space_or_tab::{space_or_tab_eol_with_options, EolOptions};
 use crate::constant::LINK_REFERENCE_SIZE_MAX;
 use crate::subtokenize::link;
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, State, Tokenizer};
+use crate::tokenizer::{ContentType, State, Tokenizer};
 
 /// Configuration.
 ///
@@ -98,7 +98,7 @@ struct Info {
 /// ```
 pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
     match tokenizer.current {
-        Code::Char('[') => {
+        Some('[') => {
             let info = Info {
                 connect: false,
                 data: false,
@@ -124,10 +124,10 @@ pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
 /// ```
 fn at_break(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::Char('[') => State::Nok,
-        Code::Char(']') if !info.data => State::Nok,
+        None | Some('[') => State::Nok,
+        Some(']') if !info.data => State::Nok,
         _ if info.size > LINK_REFERENCE_SIZE_MAX => State::Nok,
-        Code::Char(']') => {
+        Some(']') => {
             tokenizer.exit(info.options.string.clone());
             tokenizer.enter(info.options.marker.clone());
             tokenizer.consume();
@@ -135,7 +135,7 @@ fn at_break(tokenizer: &mut Tokenizer, mut info: Info) -> State {
             tokenizer.exit(info.options.label);
             State::Ok
         }
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => tokenizer.go(
+        Some('\n') => tokenizer.go(
             space_or_tab_eol_with_options(EolOptions {
                 content_type: Some(ContentType::String),
                 connect: info.connect,
@@ -168,7 +168,7 @@ fn at_break(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn label(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r' | '[' | ']') => {
+        None | Some('\n' | '[' | ']') => {
             tokenizer.exit(Token::Data);
             at_break(tokenizer, info)
         }
@@ -176,12 +176,12 @@ fn label(tokenizer: &mut Tokenizer, mut info: Info) -> State {
             tokenizer.exit(Token::Data);
             at_break(tokenizer, info)
         }
-        Code::VirtualSpace | Code::Char('\t' | ' ') => {
+        Some('\t' | ' ') => {
             tokenizer.consume();
             info.size += 1;
             State::Fn(Box::new(|t| label(t, info)))
         }
-        Code::Char('\\') => {
+        Some('\\') => {
             tokenizer.consume();
             info.size += 1;
             if !info.data {
@@ -189,7 +189,7 @@ fn label(tokenizer: &mut Tokenizer, mut info: Info) -> State {
             }
             State::Fn(Box::new(|t| escape(t, info)))
         }
-        Code::Char(_) => {
+        Some(_) => {
             tokenizer.consume();
             info.size += 1;
             if !info.data {
@@ -208,7 +208,7 @@ fn label(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn escape(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char('[' | '\\' | ']') => {
+        Some('[' | '\\' | ']') => {
             tokenizer.consume();
             info.size += 1;
             State::Fn(Box::new(|t| label(t, info)))
diff --git a/src/construct/partial_non_lazy_continuation.rs b/src/construct/partial_non_lazy_continuation.rs
index bdc22e4..068e30f 100644
--- a/src/construct/partial_non_lazy_continuation.rs
+++ b/src/construct/partial_non_lazy_continuation.rs
@@ -11,7 +11,7 @@
 //! [html_flow]: crate::construct::html_flow
 
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Start of continuation.
 ///
@@ -22,7 +22,7 @@ use crate::tokenizer::{Code, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
diff --git a/src/construct/partial_space_or_tab.rs b/src/construct/partial_space_or_tab.rs
index 5f1a917..6070ffe 100644
--- a/src/construct/partial_space_or_tab.rs
+++ b/src/construct/partial_space_or_tab.rs
@@ -6,7 +6,7 @@
 
 use crate::subtokenize::link;
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, State, StateFn, Tokenizer};
+use crate::tokenizer::{ContentType, State, StateFn, Tokenizer};
 
 /// Options to parse `space_or_tab`.
 #[derive(Debug)]
@@ -134,7 +134,7 @@ pub fn space_or_tab_eol_with_options(options: EolOptions) -> Box<StateFn> {
 /// ```
 fn start(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ') if info.options.max > 0 => {
+        Some('\t' | ' ') if info.options.max > 0 => {
             tokenizer
                 .enter_with_content(info.options.kind.clone(), info.options.content_type.clone());
 
@@ -165,7 +165,7 @@ fn start(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn inside(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::VirtualSpace | Code::Char('\t' | ' ') if info.size < info.options.max => {
+        Some('\t' | ' ') if info.size < info.options.max => {
             tokenizer.consume();
             info.size += 1;
             State::Fn(Box::new(|t| inside(t, info)))
@@ -190,7 +190,7 @@ fn inside(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn after_space_or_tab(tokenizer: &mut Tokenizer, mut info: EolInfo) -> State {
     match tokenizer.current {
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        Some('\n') => {
             tokenizer.enter_with_content(Token::LineEnding, info.options.content_type.clone());
 
             if info.connect {
@@ -239,10 +239,7 @@ fn after_eol(tokenizer: &mut Tokenizer, info: EolInfo) -> State {
 /// ```
 fn after_more_space_or_tab(tokenizer: &mut Tokenizer) -> State {
     // Blank line not allowed.
-    if matches!(
-        tokenizer.current,
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')
-    ) {
+    if matches!(tokenizer.current, None | Some('\n')) {
         State::Nok
     } else {
         State::Ok
diff --git a/src/construct/partial_title.rs b/src/construct/partial_title.rs
index e9528fd..15fc25e 100644
--- a/src/construct/partial_title.rs
+++ b/src/construct/partial_title.rs
@@ -33,7 +33,7 @@
 use super::partial_space_or_tab::{space_or_tab_eol_with_options, EolOptions};
 use crate::subtokenize::link;
 use crate::token::Token;
-use crate::tokenizer::{Code, ContentType, State, Tokenizer};
+use crate::tokenizer::{ContentType, State, Tokenizer};
 
 /// Configuration.
 ///
@@ -103,19 +103,6 @@ impl Kind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// > 👉 **Note**: an opening paren must be used for `Kind::Paren`.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not `Code::Char('(' | '"' | '\'')`.
-    fn from_code(code: Code) -> Kind {
-        match code {
-            Code::Char(char) => Kind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// State needed to parse titles.
@@ -137,10 +124,10 @@ struct Info {
 /// ```
 pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
     match tokenizer.current {
-        Code::Char('"' | '\'' | '(') => {
+        Some(char) if matches!(char, '"' | '\'' | '(') => {
             let info = Info {
                 connect: false,
-                kind: Kind::from_code(tokenizer.current),
+                kind: Kind::from_char(char),
                 options,
             };
             tokenizer.enter(info.options.title.clone());
@@ -163,7 +150,7 @@ pub fn start(tokenizer: &mut Tokenizer, options: Options) -> State {
 /// ```
 fn begin(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.enter(info.options.marker.clone());
             tokenizer.consume();
             tokenizer.exit(info.options.marker.clone());
@@ -185,12 +172,12 @@ fn begin(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn at_break(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.exit(info.options.string.clone());
             begin(tokenizer, info)
         }
-        Code::None => State::Nok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => tokenizer.go(
+        None => State::Nok,
+        Some('\n') => tokenizer.go(
             space_or_tab_eol_with_options(EolOptions {
                 content_type: Some(ContentType::String),
                 connect: info.connect,
@@ -223,15 +210,15 @@ fn at_break(tokenizer: &mut Tokenizer, mut info: Info) -> State {
 /// ```
 fn title(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.exit(Token::Data);
             at_break(tokenizer, info)
         }
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None | Some('\n') => {
             tokenizer.exit(Token::Data);
             at_break(tokenizer, info)
         }
-        Code::Char('\\') => {
+        Some('\\') => {
             tokenizer.consume();
             State::Fn(Box::new(|t| escape(t, info)))
         }
@@ -250,7 +237,7 @@ fn title(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn escape(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.consume();
             State::Fn(Box::new(|t| title(t, info)))
         }
diff --git a/src/construct/partial_whitespace.rs b/src/construct/partial_whitespace.rs
index 4c94c7d..152824b 100644
--- a/src/construct/partial_whitespace.rs
+++ b/src/construct/partial_whitespace.rs
@@ -47,8 +47,8 @@
 
 use crate::constant::HARD_BREAK_PREFIX_SIZE_MIN;
 use crate::token::Token;
-use crate::tokenizer::{Code, Event, EventType, Tokenizer};
-use crate::util::span;
+use crate::tokenizer::{Event, EventType, Tokenizer};
+use crate::util::slice::{Position, Slice};
 
 /// To do.
 pub fn create_resolve_whitespace(hard_break: bool, trim_whole: bool) -> impl Fn(&mut Tokenizer) {
@@ -85,30 +85,26 @@ fn trim_data(
     trim_end: bool,
     hard_break: bool,
 ) {
-    let mut codes = span::codes(
-        &tokenizer.parse_state.codes,
-        &span::from_exit_event(&tokenizer.events, exit_index),
+    let mut slice = Slice::from_position(
+        &tokenizer.parse_state.chars,
+        &Position::from_exit_event(&tokenizer.events, exit_index),
     );
 
     if trim_end {
-        let mut index = codes.len();
-        let mut vs = 0;
-        let mut spaces_only = true;
+        let mut index = slice.chars.len();
+        let vs = slice.after;
+        let mut spaces_only = vs == 0;
         while index > 0 {
-            match codes[index - 1] {
-                Code::Char(' ') => {}
-                Code::Char('\t') => spaces_only = false,
-                Code::VirtualSpace => {
-                    vs += 1;
-                    spaces_only = false;
-                }
+            match slice.chars[index - 1] {
+                ' ' => {}
+                '\t' => spaces_only = false,
                 _ => break,
             }
 
             index -= 1;
         }
 
-        let diff = codes.len() - index;
+        let diff = slice.chars.len() - index;
         let token_type = if spaces_only
             && hard_break
             && exit_index + 1 < tokenizer.events.len()
@@ -127,12 +123,12 @@ fn trim_data(
             return;
         }
 
-        if diff > 0 {
+        if diff > 0 || vs > 0 {
             let exit_point = tokenizer.events[exit_index].point.clone();
             let mut enter_point = exit_point.clone();
             enter_point.index -= diff;
-            enter_point.column -= diff - vs;
-            enter_point.offset -= diff - vs;
+            enter_point.column -= diff;
+            enter_point.vs = 0;
 
             tokenizer.map.add(
                 exit_index + 1,
@@ -154,17 +150,16 @@ fn trim_data(
             );
 
             tokenizer.events[exit_index].point = enter_point;
-            codes = &codes[..index];
+            slice.chars = &slice.chars[..index];
         }
     }
 
     if trim_start {
         let mut index = 0;
-        let mut vs = 0;
-        while index < codes.len() {
-            match codes[index] {
-                Code::Char(' ' | '\t') => {}
-                Code::VirtualSpace => vs += 1,
+        let vs = slice.before;
+        while index < slice.chars.len() {
+            match slice.chars[index] {
+                ' ' | '\t' => {}
                 _ => break,
             }
 
@@ -173,18 +168,18 @@ fn trim_data(
 
         // The whole data is whitespace.
         // We can be very fast: we only change the token types.
-        if index == codes.len() {
+        if index == slice.chars.len() {
             tokenizer.events[exit_index - 1].token_type = Token::SpaceOrTab;
             tokenizer.events[exit_index].token_type = Token::SpaceOrTab;
             return;
         }
 
-        if index > 0 {
+        if index > 0 || vs > 0 {
             let enter_point = tokenizer.events[exit_index - 1].point.clone();
             let mut exit_point = enter_point.clone();
             exit_point.index += index;
-            exit_point.column += index - vs;
-            exit_point.offset += index - vs;
+            exit_point.column += index;
+            exit_point.vs = 0;
 
             tokenizer.map.add(
                 exit_index - 1,
diff --git a/src/construct/thematic_break.rs b/src/construct/thematic_break.rs
index 41dc6ae..bed454b 100644
--- a/src/construct/thematic_break.rs
+++ b/src/construct/thematic_break.rs
@@ -51,7 +51,7 @@
 use super::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
 use crate::constant::{TAB_SIZE, THEMATIC_BREAK_MARKER_COUNT_MIN};
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Type of thematic break.
 #[derive(Debug, PartialEq)]
@@ -104,19 +104,6 @@ impl Kind {
             _ => unreachable!("invalid char"),
         }
     }
-    /// Turn [Code] into a kind.
-    ///
-    /// > 👉 **Note**: an opening paren must be used for `Kind::Paren`.
-    ///
-    /// ## Panics
-    ///
-    /// Panics if `code` is not `Code::Char('*' | '-' | '_')`.
-    fn from_code(code: Code) -> Kind {
-        match code {
-            Code::Char(char) => Kind::from_char(char),
-            _ => unreachable!("invalid code"),
-        }
-    }
 }
 
 /// State needed to parse thematic breaks.
@@ -157,10 +144,10 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::Char('*' | '-' | '_') => at_break(
+        Some(char) if matches!(char, '*' | '-' | '_') => at_break(
             tokenizer,
             Info {
-                kind: Kind::from_code(tokenizer.current),
+                kind: Kind::from_char(char),
                 size: 0,
             },
         ),
@@ -176,15 +163,13 @@ fn before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn at_break(tokenizer: &mut Tokenizer, info: Info) -> State {
     match tokenizer.current {
-        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')
-            if info.size >= THEMATIC_BREAK_MARKER_COUNT_MIN =>
-        {
+        None | Some('\n' | '\r') if info.size >= THEMATIC_BREAK_MARKER_COUNT_MIN => {
             tokenizer.exit(Token::ThematicBreak);
             // Feel free to interrupt.
             tokenizer.interrupt = false;
             State::Ok
         }
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.enter(Token::ThematicBreakSequence);
             sequence(tokenizer, info)
         }
@@ -200,7 +185,7 @@ fn at_break(tokenizer: &mut Tokenizer, info: Info) -> State {
 /// ```
 fn sequence(tokenizer: &mut Tokenizer, mut info: Info) -> State {
     match tokenizer.current {
-        Code::Char(char) if char == info.kind.as_char() => {
+        Some(char) if char == info.kind.as_char() => {
             tokenizer.consume();
             info.size += 1;
             State::Fn(Box::new(|t| sequence(t, info)))
diff --git a/src/content/document.rs b/src/content/document.rs
index 32b32ba..2924f6c 100644
--- a/src/content/document.rs
+++ b/src/content/document.rs
@@ -17,12 +17,12 @@ use crate::parser::ParseState;
 use crate::subtokenize::subtokenize;
 use crate::token::Token;
 use crate::tokenizer::{
-    Code, Container, ContainerState, Event, EventType, Point, State, StateFn, Tokenizer,
+    Container, ContainerState, Event, EventType, Point, State, StateFn, Tokenizer,
 };
 use crate::util::{
     normalize_identifier::normalize_identifier,
     skip,
-    span::{from_exit_event, serialize},
+    slice::{Position, Slice},
 };
 
 /// Phases where we can exit containers.
@@ -78,7 +78,7 @@ struct DocumentInfo {
 pub fn document(parse_state: &mut ParseState, point: Point) -> Vec<Event> {
     let mut tokenizer = Tokenizer::new(point, parse_state);
 
-    let state = tokenizer.push(0, parse_state.codes.len(), Box::new(start));
+    let state = tokenizer.push(0, parse_state.chars.len(), Box::new(before));
     tokenizer.flush(state, true);
 
     let mut index = 0;
@@ -88,13 +88,14 @@ pub fn document(parse_state: &mut ParseState, point: Point) -> Vec<Event> {
         let event = &tokenizer.events[index];
 
         if event.event_type == EventType::Exit && event.token_type == Token::DefinitionLabelString {
+            // To do: when we operate on u8, we can use a `to_str` here as we
+            // don‘t need virtual spaces.
             let id = normalize_identifier(
-                serialize(
-                    &parse_state.codes,
-                    &from_exit_event(&tokenizer.events, index),
-                    false,
+                &Slice::from_position(
+                    &tokenizer.parse_state.chars,
+                    &Position::from_exit_event(&tokenizer.events, index),
                 )
-                .as_str(),
+                .serialize(),
             );
 
             if !definitions.contains(&id) {
@@ -114,6 +115,26 @@ pub fn document(parse_state: &mut ParseState, point: Point) -> Vec<Event> {
     events
 }
 
+/// At the beginning.
+///
+/// Perhaps a BOM?
+///
+/// ```markdown
+/// > | a
+///     ^
+/// ```
+fn before(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        Some('\u{FEFF}') => {
+            tokenizer.enter(Token::ByteOrderMark);
+            tokenizer.consume();
+            tokenizer.exit(Token::ByteOrderMark);
+            State::Fn(Box::new(start))
+        }
+        _ => start(tokenizer),
+    }
+}
+
 /// Before document.
 //
 /// ```markdown
@@ -337,7 +358,7 @@ fn containers_after(tokenizer: &mut Tokenizer, mut info: DocumentInfo) -> State
     // Parse flow, pausing after eols.
     tokenizer.go_until(
         state,
-        |code| matches!(code, Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')),
+        |code| matches!(code, Some('\n')),
         move |state| Box::new(move |t| flow_end(t, info, state)),
     )(tokenizer)
 }
diff --git a/src/content/flow.rs b/src/content/flow.rs
index ea09cd9..09c4e2c 100644
--- a/src/content/flow.rs
+++ b/src/content/flow.rs
@@ -27,7 +27,7 @@ use crate::construct::{
     thematic_break::start as thematic_break,
 };
 use crate::token::Token;
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
 /// Before flow.
 ///
@@ -41,7 +41,7 @@ use crate::tokenizer::{Code, State, Tokenizer};
 /// ```
 pub fn start(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
+        None => State::Ok,
         _ => tokenizer.attempt(blank_line, |ok| {
             Box::new(if ok { blank_line_after } else { initial_before })
         })(tokenizer),
@@ -62,7 +62,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn initial_before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
+        None => State::Ok,
         _ => tokenizer.attempt_n(
             vec![
                 Box::new(code_indented),
@@ -87,8 +87,8 @@ fn initial_before(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn blank_line_after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None => State::Ok,
+        Some('\n') => {
             tokenizer.enter(Token::BlankLineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::BlankLineEnding);
@@ -111,8 +111,8 @@ fn blank_line_after(tokenizer: &mut Tokenizer) -> State {
 /// ```
 fn after(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
-        Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+        None => State::Ok,
+        Some('\n') => {
             tokenizer.enter(Token::LineEnding);
             tokenizer.consume();
             tokenizer.exit(Token::LineEnding);
diff --git a/src/content/string.rs b/src/content/string.rs
index c6c0094..8bc2b91 100644
--- a/src/content/string.rs
+++ b/src/content/string.rs
@@ -16,9 +16,9 @@ use crate::construct::{
     character_escape::start as character_escape, character_reference::start as character_reference,
     partial_data::start as data, partial_whitespace::create_resolve_whitespace,
 };
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
-const MARKERS: [Code; 2] = [Code::Char('&'), Code::Char('\\')];
+const MARKERS: [char; 2] = ['&', '\\'];
 
 /// Start of string.
 pub fn start(tokenizer: &mut Tokenizer) -> State {
@@ -32,7 +32,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// Before string.
 fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
+        None => State::Ok,
         _ => tokenizer.attempt_n(
             vec![Box::new(character_reference), Box::new(character_escape)],
             |ok| Box::new(if ok { before } else { before_data }),
diff --git a/src/content/text.rs b/src/content/text.rs
index 4248053..ebdf888 100644
--- a/src/content/text.rs
+++ b/src/content/text.rs
@@ -28,18 +28,18 @@ use crate::construct::{
     label_start_image::start as label_start_image, label_start_link::start as label_start_link,
     partial_data::start as data, partial_whitespace::create_resolve_whitespace,
 };
-use crate::tokenizer::{Code, State, Tokenizer};
+use crate::tokenizer::{State, Tokenizer};
 
-const MARKERS: [Code; 9] = [
-    Code::Char('!'),  // `label_start_image`
-    Code::Char('&'),  // `character_reference`
-    Code::Char('*'),  // `attention`
-    Code::Char('<'),  // `autolink`, `html_text`
-    Code::Char('['),  // `label_start_link`
-    Code::Char('\\'), // `character_escape`, `hard_break_escape`
-    Code::Char(']'),  // `label_end`
-    Code::Char('_'),  // `attention`
-    Code::Char('`'),  // `code_text`
+const MARKERS: [char; 9] = [
+    '!',  // `label_start_image`
+    '&',  // `character_reference`
+    '*',  // `attention`
+    '<',  // `autolink`, `html_text`
+    '[',  // `label_start_link`
+    '\\', // `character_escape`, `hard_break_escape`
+    ']',  // `label_end`
+    '_',  // `attention`
+    '`',  // `code_text`
 ];
 
 /// Start of text.
@@ -57,7 +57,7 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
 /// Before text.
 pub fn before(tokenizer: &mut Tokenizer) -> State {
     match tokenizer.current {
-        Code::None => State::Ok,
+        None => State::Ok,
         _ => tokenizer.attempt_n(
             vec![
                 Box::new(attention),
diff --git a/src/lib.rs b/src/lib.rs
index 4dc15e6..c1b0fa0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,7 +17,6 @@ mod util;
 
 use crate::compiler::compile;
 use crate::parser::parse;
-use crate::tokenizer::Code;
 
 /// Type of line endings in markdown.
 #[derive(Debug, Default, Clone, PartialEq)]
@@ -61,16 +60,16 @@ impl LineEnding {
             LineEnding::LineFeed => "\n",
         }
     }
-    /// Turn a [Code] into a line ending.
+    /// Turn a string into a line ending.
     ///
     /// ## Panics
     ///
     /// Panics if `code` is not `\r\n`, `\r`, or `\n`.
-    fn from_code(code: Code) -> LineEnding {
-        match code {
-            Code::CarriageReturnLineFeed => LineEnding::CarriageReturnLineFeed,
-            Code::Char('\r') => LineEnding::CarriageReturn,
-            Code::Char('\n') => LineEnding::LineFeed,
+    fn from_str(str: &str) -> LineEnding {
+        match str {
+            "\r\n" => LineEnding::CarriageReturnLineFeed,
+            "\r" => LineEnding::CarriageReturn,
+            "\n" => LineEnding::LineFeed,
             _ => unreachable!("invalid code"),
         }
     }
@@ -425,5 +424,5 @@ pub fn micromark(value: &str) -> String {
 #[must_use]
 pub fn micromark_with_options(value: &str, options: &Options) -> String {
     let (events, result) = parse(value, options);
-    compile(&events, &result.codes, options)
+    compile(&events, &result.chars, options)
 }
diff --git a/src/parser.rs b/src/parser.rs
index 0f71daf..cc9c256 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,19 +1,18 @@
 //! Turn a string of markdown into events.
 
 use crate::content::document::document;
-use crate::tokenizer::{Code, Event, Point};
-use crate::util::codes::parse as parse_codes;
+use crate::tokenizer::{Event, Point};
 use crate::{Constructs, Options};
 
 /// Information needed, in all content types, when parsing markdown.
 ///
 /// Importantly, this contains a set of known definitions.
-/// It also references the input value as [`Code`][]s.
+/// It also references the input value as a `Vec<char>`.
 #[derive(Debug)]
 pub struct ParseState<'a> {
     pub constructs: &'a Constructs,
-    /// List of codes.
-    pub codes: Vec<Code>,
+    /// List of chars.
+    pub chars: Vec<char>,
     /// Set of defined identifiers.
     pub definitions: Vec<String>,
 }
@@ -24,7 +23,8 @@ pub struct ParseState<'a> {
 pub fn parse<'a>(value: &str, options: &'a Options) -> (Vec<Event>, ParseState<'a>) {
     let mut parse_state = ParseState {
         constructs: &options.constructs,
-        codes: parse_codes(value),
+        // To do: change to `u8`s?
+        chars: value.chars().collect::<_>(),
         definitions: vec![],
     };
 
@@ -33,8 +33,8 @@ pub fn parse<'a>(value: &str, options: &'a Options) -> (Vec<Event>, ParseState<'
         Point {
             line: 1,
             column: 1,
-            offset: 0,
             index: 0,
+            vs: 0,
         },
     );
 
diff --git a/src/token.rs b/src/token.rs
index a0479e1..db3bffc 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -157,6 +157,17 @@ pub enum Token {
     ///   | b
     /// ```
     BlockQuotePrefix,
+    /// Byte order mark.
+    ///
+    /// ## Info
+    ///
+    /// *   **Context**:
+    ///     optional first event
+    /// *   **Content model**:
+    ///     void
+    /// *   **Construct**:
+    ///     [`document`][crate::content::document]
+    ByteOrderMark,
     /// Whole character escape.
     ///
     /// ## Info
@@ -1822,13 +1833,14 @@ pub enum Token {
 }
 
 /// List of void tokens, used to make sure everything is working good.
-pub const VOID_TOKENS: [Token; 39] = [
+pub const VOID_TOKENS: [Token; 40] = [
     Token::AttentionSequence,
     Token::AutolinkEmail,
     Token::AutolinkMarker,
     Token::AutolinkProtocol,
     Token::BlankLineEnding,
     Token::BlockQuoteMarker,
+    Token::ByteOrderMark,
     Token::CharacterEscapeMarker,
     Token::CharacterEscapeValue,
     Token::CharacterReferenceMarker,
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index ba18956..ec70a2b 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -11,6 +11,7 @@
 //! [`attempt`]: Tokenizer::attempt
 //! [`check`]: Tokenizer::check
 
+use crate::constant::TAB_SIZE;
 use crate::parser::ParseState;
 use crate::token::{Token, VOID_TOKENS};
 use crate::util::edit_map::EditMap;
@@ -24,20 +25,11 @@ pub enum ContentType {
     String,
 }
 
-/// Enum representing a character code.
-#[derive(Debug, Clone, Copy, PartialEq)]
-pub enum Code {
-    /// End of the input stream (called eof).
-    None,
-    /// Used to make parsing line endings easier as it represents both
-    /// `Code::Char('\r')` and `Code::Char('\n')` combined.
-    CarriageReturnLineFeed,
-    /// the expansion of a tab (`Code::Char('\t')`), depending on where the tab
-    /// ocurred, it’s followed by 0 to 3 (both inclusive) `Code::VirtualSpace`s.
-    VirtualSpace,
-    /// The most frequent variant of this enum is `Code::Char(char)`, which just
-    /// represents a char, but micromark adds meaning to certain other values.
-    Char(char),
+#[derive(Debug, PartialEq)]
+pub enum CharAction {
+    Normal(char),
+    Insert(char),
+    Ignore,
 }
 
 /// A location in the document (`line`/`column`/`offset`).
@@ -54,9 +46,12 @@ pub struct Point {
     /// the same as editors.
     pub column: usize,
     /// 0-indexed position in the document.
-    pub offset: usize,
-    /// Index into `codes`.
+    ///
+    /// Also an `index` into `codes`.
+    // To do: call it `offset`?
     pub index: usize,
+    /// To do.
+    pub vs: usize,
 }
 
 /// Possible event types.
@@ -86,7 +81,7 @@ pub struct Event {
 }
 
 /// The essence of the state machine are functions: `StateFn`.
-/// It’s responsible for dealing with that single passed [`Code`][].
+/// It’s responsible for dealing with the current char.
 /// It yields a [`State`][].
 pub type StateFn = dyn FnOnce(&mut Tokenizer) -> State;
 
@@ -162,9 +157,9 @@ struct InternalState {
     /// Length of the stack. It’s not allowed to decrease the stack in a check or an attempt.
     stack_len: usize,
     /// Previous code.
-    previous: Code,
+    previous: Option<char>,
     /// Current code.
-    current: Code,
+    current: Option<char>,
     /// Current relative and absolute position in the file.
     point: Point,
 }
@@ -173,9 +168,11 @@ struct InternalState {
 #[allow(clippy::struct_excessive_bools)]
 pub struct Tokenizer<'a> {
     /// Jump between line endings.
-    column_start: Vec<usize>,
+    column_start: Vec<(usize, usize)>,
     // First line.
-    line_start: usize,
+    first_line: usize,
+    /// To do.
+    line_start: Point,
     /// Track whether a character is expected to be consumed, and whether it’s
     /// actually consumed
     ///
@@ -184,9 +181,9 @@ pub struct Tokenizer<'a> {
     /// Track whether this tokenizer is done.
     resolved: bool,
     /// Current character code.
-    pub current: Code,
+    pub current: Option<char>,
     /// Previous character code.
-    pub previous: Code,
+    pub previous: Option<char>,
     /// Current relative and absolute place in the file.
     pub point: Point,
     /// Semantic labels of one or more codes in `codes`.
@@ -237,11 +234,12 @@ impl<'a> Tokenizer<'a> {
     /// Create a new tokenizer.
     pub fn new(point: Point, parse_state: &'a ParseState) -> Tokenizer<'a> {
         Tokenizer {
-            previous: Code::None,
-            current: Code::None,
+            previous: None,
+            current: None,
             // To do: reserve size when feeding?
             column_start: vec![],
-            line_start: point.line,
+            first_line: point.line,
+            line_start: point.clone(),
             consumed: true,
             resolved: false,
             point,
@@ -280,18 +278,18 @@ impl<'a> Tokenizer<'a> {
 
     /// Define a jump between two places.
     pub fn define_skip(&mut self, point: &Point) {
-        define_skip_impl(self, point.line, point.index);
+        define_skip_impl(self, point.line, (point.index, point.vs));
     }
 
     /// Define the current place as a jump between two places.
     pub fn define_skip_current(&mut self) {
-        define_skip_impl(self, self.point.line, self.point.index);
+        define_skip_impl(self, self.point.line, (self.point.index, self.point.vs));
     }
 
     /// Increment the current positional info if we’re right after a line
     /// ending, which has a skip defined.
     fn account_for_potential_skip(&mut self) {
-        let at = self.point.line - self.line_start;
+        let at = self.point.line - self.first_line;
 
         if self.point.column == 1 && at != self.column_start.len() {
             self.move_to(self.column_start[at]);
@@ -299,10 +297,10 @@ impl<'a> Tokenizer<'a> {
     }
 
     /// Prepare for a next code to get consumed.
-    pub fn expect(&mut self, code: Code) {
+    pub fn expect(&mut self, char: Option<char>) {
         assert!(self.consumed, "expected previous character to be consumed");
         self.consumed = false;
-        self.current = code;
+        self.current = char;
     }
 
     /// Consume the current character.
@@ -311,46 +309,60 @@ impl<'a> Tokenizer<'a> {
     pub fn consume(&mut self) {
         log::debug!("consume: `{:?}` ({:?})", self.current, self.point);
         assert!(!self.consumed, "expected code to not have been consumed: this might be because `x(code)` instead of `x` was returned");
-        self.move_to(self.point.index + 1);
+
+        self.move_one();
+
         self.previous = self.current;
+        // While we’re not at the eof, it is at least better to not have the
+        // same current code as `previous` *and* `current`.
+        self.current = None;
         // Mark as consumed.
         self.consumed = true;
     }
 
-    /// To do.
-    pub fn move_to(&mut self, to: usize) {
-        while self.point.index < to {
-            let code = &self.parse_state.codes[self.point.index];
-            self.point.index += 1;
+    /// Move to the next (virtual) character.
+    pub fn move_one(&mut self) {
+        match char_action(&self.parse_state.chars, &self.point) {
+            CharAction::Ignore => {
+                self.point.index += 1;
+            }
+            CharAction::Insert(char) => {
+                self.previous = Some(char);
+                self.point.column += 1;
+                self.point.vs += 1;
+            }
+            CharAction::Normal(char) => {
+                self.previous = Some(char);
+                self.point.vs = 0;
+                self.point.index += 1;
 
-            match code {
-                Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
+                if char == '\n' {
                     self.point.line += 1;
                     self.point.column = 1;
-                    self.point.offset += if *code == Code::CarriageReturnLineFeed {
-                        2
-                    } else {
-                        1
-                    };
 
-                    if self.point.line - self.line_start + 1 > self.column_start.len() {
-                        self.column_start.push(self.point.index);
+                    if self.point.line - self.first_line + 1 > self.column_start.len() {
+                        self.column_start.push((self.point.index, self.point.vs));
                     }
 
+                    self.line_start = self.point.clone();
+
                     self.account_for_potential_skip();
                     log::debug!("position: after eol: `{:?}`", self.point);
-                }
-                Code::VirtualSpace => {
-                    // Empty.
-                }
-                _ => {
+                } else {
                     self.point.column += 1;
-                    self.point.offset += 1;
                 }
             }
         }
     }
 
+    /// Move (virtual) characters.
+    pub fn move_to(&mut self, to: (usize, usize)) {
+        let (to_index, to_vs) = to;
+        while self.point.index < to_index || self.point.index == to_index && self.point.vs < to_vs {
+            self.move_one();
+        }
+    }
+
     /// Mark the start of a semantic label.
     pub fn enter(&mut self, token_type: Token) {
         self.enter_with_link(token_type, None);
@@ -368,11 +380,23 @@ impl<'a> Tokenizer<'a> {
     }
 
     pub fn enter_with_link(&mut self, token_type: Token, link: Option<Link>) {
-        log::debug!("enter: `{:?}` ({:?})", token_type, self.point);
+        let mut point = self.point.clone();
+
+        // Move back past ignored chars.
+        while point.index > 0 {
+            point.index -= 1;
+            let action = char_action(&self.parse_state.chars, &point);
+            if !matches!(action, CharAction::Ignore) {
+                point.index += 1;
+                break;
+            }
+        }
+
+        log::debug!("enter: `{:?}` ({:?})", token_type, point);
         self.events.push(Event {
             event_type: EventType::Enter,
             token_type: token_type.clone(),
-            point: self.point.clone(),
+            point,
             link,
         });
         self.stack.push(token_type);
@@ -391,7 +415,9 @@ impl<'a> Tokenizer<'a> {
         let mut point = self.point.clone();
 
         assert!(
-            current_token != previous.token_type || previous.point.index != point.index,
+            current_token != previous.token_type
+                || previous.point.index != point.index
+                || previous.point.vs != point.vs,
             "expected non-empty token"
         );
 
@@ -406,18 +432,18 @@ impl<'a> Tokenizer<'a> {
 
         // A bit weird, but if we exit right after a line ending, we *don’t* want to consider
         // potential skips.
-        if matches!(
-            self.previous,
-            Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')
-        ) {
-            point.column = 1;
-            point.offset = previous.point.offset
-                + if self.previous == Code::CarriageReturnLineFeed {
-                    2
-                } else {
-                    1
-                };
-            point.index = previous.point.index + 1;
+        if matches!(self.previous, Some('\n')) {
+            point = self.line_start.clone();
+        } else {
+            // Move back past ignored chars.
+            while point.index > 0 {
+                point.index -= 1;
+                let action = char_action(&self.parse_state.chars, &point);
+                if !matches!(action, CharAction::Ignore) {
+                    point.index += 1;
+                    break;
+                }
+            }
         }
 
         log::debug!("exit: `{:?}` ({:?})", token_type, point);
@@ -494,7 +520,7 @@ impl<'a> Tokenizer<'a> {
     pub fn go_until(
         &mut self,
         state_fn: impl FnOnce(&mut Tokenizer) -> State + 'static,
-        until: impl Fn(Code) -> bool + 'static,
+        until: impl Fn(Option<char>) -> bool + 'static,
         done: impl FnOnce(State) -> Box<StateFn> + 'static,
     ) -> Box<StateFn> {
         attempt_impl(
@@ -619,19 +645,32 @@ impl<'a> Tokenizer<'a> {
         assert!(!self.resolved, "cannot feed after drain");
         assert!(min >= self.point.index, "cannot move backwards");
 
-        self.move_to(min);
+        // To do: accept `vs`?
+        self.move_to((min, 0));
 
         let mut state = State::Fn(Box::new(start));
 
         while self.point.index < max {
             match state {
                 State::Ok | State::Nok => break,
-                State::Fn(func) => {
-                    let code = self.parse_state.codes[self.point.index];
-                    log::debug!("main: passing: `{:?}` ({:?})", code, self.point);
-                    self.expect(code);
-                    state = func(self);
-                }
+                State::Fn(func) => match char_action(&self.parse_state.chars, &self.point) {
+                    CharAction::Ignore => {
+                        state = State::Fn(Box::new(func));
+                        self.move_one();
+                    }
+                    CharAction::Insert(char) => {
+                        log::debug!("main: passing (fake): `{:?}` ({:?})", char, self.point);
+                        self.expect(Some(char));
+                        state = func(self);
+                        // self.point.column += 1;
+                        // self.point.vs += 1;
+                    }
+                    CharAction::Normal(char) => {
+                        log::debug!("main: passing: `{:?}` ({:?})", char, self.point);
+                        self.expect(Some(char));
+                        state = func(self);
+                    }
+                },
             }
         }
 
@@ -648,15 +687,35 @@ impl<'a> Tokenizer<'a> {
             match state {
                 State::Ok | State::Nok => break,
                 State::Fn(func) => {
+                    // To do: clean this?
                     // We sometimes move back when flushing, so then we use those codes.
-                    let code = if self.point.index < max {
-                        self.parse_state.codes[self.point.index]
+                    if self.point.index == max {
+                        let char = None;
+                        log::debug!("main: flushing eof: `{:?}` ({:?})", char, self.point);
+                        self.expect(char);
+                        state = func(self);
                     } else {
-                        Code::None
+                        match char_action(&self.parse_state.chars, &self.point) {
+                            CharAction::Ignore => {
+                                state = State::Fn(Box::new(func));
+                                self.move_one();
+                            }
+                            CharAction::Insert(char) => {
+                                log::debug!(
+                                    "main: flushing (fake): `{:?}` ({:?})",
+                                    char,
+                                    self.point
+                                );
+                                self.expect(Some(char));
+                                state = func(self);
+                            }
+                            CharAction::Normal(char) => {
+                                log::debug!("main: flushing: `{:?}` ({:?})", char, self.point);
+                                self.expect(Some(char));
+                                state = func(self);
+                            }
+                        }
                     };
-                    log::debug!("main: flushing {:?}", code);
-                    self.expect(code);
-                    state = func(self);
                 }
             }
         }
@@ -676,13 +735,58 @@ impl<'a> Tokenizer<'a> {
     }
 }
 
+fn char_action(chars: &[char], point: &Point) -> CharAction {
+    if point.index < chars.len() {
+        let char = chars[point.index];
+
+        if char == '\0' {
+            CharAction::Normal(char::REPLACEMENT_CHARACTER)
+        } else if char == '\r' {
+            // CRLF.
+            if point.index < chars.len() - 1 && chars[point.index + 1] == '\n' {
+                CharAction::Ignore
+            }
+            // CR.
+            else {
+                CharAction::Normal('\n')
+            }
+        } else if char == '\t' {
+            let remainder = point.column % TAB_SIZE;
+            let vs = if remainder == 0 {
+                0
+            } else {
+                TAB_SIZE - remainder
+            };
+
+            // On the tab itself, first send it.
+            if point.vs == 0 {
+                if vs == 0 {
+                    CharAction::Normal(char)
+                } else {
+                    CharAction::Insert(char)
+                }
+            } else if vs == 0 {
+                CharAction::Normal(' ')
+            } else {
+                CharAction::Insert(' ')
+            }
+        }
+        // VS?
+        else {
+            CharAction::Normal(char)
+        }
+    } else {
+        unreachable!("out of bounds")
+    }
+}
+
 /// Internal utility to wrap states to also capture codes.
 ///
 /// Recurses into itself.
 /// Used in [`Tokenizer::attempt`][Tokenizer::attempt] and  [`Tokenizer::check`][Tokenizer::check].
 fn attempt_impl(
     state: impl FnOnce(&mut Tokenizer) -> State + 'static,
-    pause: Option<Box<dyn Fn(Code) -> bool + 'static>>,
+    pause: Option<Box<dyn Fn(Option<char>) -> bool + 'static>>,
     start: usize,
     done: impl FnOnce(&mut Tokenizer, State) -> State + 'static,
 ) -> Box<StateFn> {
@@ -706,14 +810,14 @@ fn attempt_impl(
 /// Define a jump between two places.
 ///
 /// This defines to which future index we move after a line ending.
-fn define_skip_impl(tokenizer: &mut Tokenizer, line: usize, index: usize) {
-    log::debug!("position: define skip: {:?} -> ({:?})", line, index);
-    let at = line - tokenizer.line_start;
+fn define_skip_impl(tokenizer: &mut Tokenizer, line: usize, info: (usize, usize)) {
+    log::debug!("position: define skip: {:?} -> ({:?})", line, info);
+    let at = line - tokenizer.first_line;
 
-    if at == tokenizer.column_start.len() {
-        tokenizer.column_start.push(index);
+    if at >= tokenizer.column_start.len() {
+        tokenizer.column_start.push(info);
     } else {
-        tokenizer.column_start[at] = index;
+        tokenizer.column_start[at] = info;
     }
 
     tokenizer.account_for_potential_skip();
diff --git a/src/util/codes.rs b/src/util/codes.rs
deleted file mode 100644
index 5006a00..0000000
--- a/src/util/codes.rs
+++ /dev/null
@@ -1,125 +0,0 @@
-//! Utilities to deal with character codes.
-
-use crate::constant::TAB_SIZE;
-use crate::tokenizer::Code;
-
-/// Turn a string into codes.
-pub fn parse(value: &str) -> Vec<Code> {
-    // Note: It’ll grow a bit bigger with each `Code::VirtualSpace`, smaller
-    // with `Code::CarriageReturnLineFeed`.
-    let mut codes = Vec::with_capacity(value.len());
-    let mut at_start = true;
-    let mut at_carriage_return = false;
-    let mut column = 1;
-
-    for char in value.chars() {
-        if at_start {
-            at_start = false;
-
-            if char == '\u{feff}' {
-                // Ignore.
-                continue;
-            }
-        }
-
-        // Send a CRLF.
-        if at_carriage_return && '\n' == char {
-            at_carriage_return = false;
-            codes.push(Code::CarriageReturnLineFeed);
-        } else {
-            // Send the previous CR: we’re not at a next `\n`.
-            if at_carriage_return {
-                at_carriage_return = false;
-                codes.push(Code::Char('\r'));
-            }
-
-            match char {
-                // Send a replacement character.
-                '\0' => {
-                    column += 1;
-                    codes.push(Code::Char(char::REPLACEMENT_CHARACTER));
-                }
-                // Send a tab and virtual spaces.
-                '\t' => {
-                    let remainder = column % TAB_SIZE;
-                    let mut virtual_spaces = if remainder == 0 {
-                        0
-                    } else {
-                        TAB_SIZE - remainder
-                    };
-                    codes.push(Code::Char(char));
-                    column += 1;
-                    while virtual_spaces > 0 {
-                        codes.push(Code::VirtualSpace);
-                        column += 1;
-                        virtual_spaces -= 1;
-                    }
-                }
-                // Send an LF.
-                '\n' => {
-                    column = 1;
-                    codes.push(Code::Char(char));
-                }
-                // Don’t send anything yet.
-                '\r' => {
-                    column = 1;
-                    at_carriage_return = true;
-                }
-                // Send the char.
-                _ => {
-                    column += 1;
-                    codes.push(Code::Char(char));
-                }
-            }
-        };
-    }
-
-    // Send the last CR: we’re not at a next `\n`.
-    if at_carriage_return {
-        codes.push(Code::Char('\r'));
-    }
-
-    codes
-}
-
-/// Serialize codes, optionally expanding tabs.
-pub fn serialize(codes: &[Code], expand_tabs: bool) -> String {
-    let mut at_tab = false;
-    // Note: It’ll grow a bit smaller with each
-    // `Code::Char('\t') | Code::VirtualSpace` if `expand_tabs` is false,
-    // and bigger with `Code::CarriageReturnLineFeed`,
-    let mut value = String::with_capacity(codes.len());
-
-    for code in codes {
-        let mut at_tab_next = false;
-
-        match code {
-            Code::CarriageReturnLineFeed => {
-                value.push_str("\r\n");
-            }
-            Code::Char(char) if *char == '\n' || *char == '\r' => {
-                value.push(*char);
-            }
-            Code::Char(char) if *char == '\t' => {
-                at_tab_next = true;
-                value.push(if expand_tabs { ' ' } else { *char });
-            }
-            Code::VirtualSpace => {
-                if !expand_tabs && at_tab {
-                    continue;
-                }
-                value.push(' ');
-            }
-            Code::Char(char) => {
-                value.push(*char);
-            }
-            Code::None => {
-                unreachable!("unexpected EOF code in codes");
-            }
-        }
-
-        at_tab = at_tab_next;
-    }
-
-    value
-}
diff --git a/src/util/encode.rs b/src/util/encode.rs
index 965ea5c..91c5462 100644
--- a/src/util/encode.rs
+++ b/src/util/encode.rs
@@ -20,7 +20,8 @@
 /// ## References
 ///
 /// *   [`micromark-util-encode` in `micromark`](https://github.com/micromark/micromark/tree/main/packages/micromark-util-encode)
-pub fn encode<S: Into<String>>(value: S) -> String {
+pub fn encode<S: Into<String>>(value: S, encode_html: bool) -> String {
+    let check = if encode_html { check_all } else { check_nil };
     let mut value = value.into();
 
     // It’ll grow a bit bigger for each dangerous character.
@@ -31,6 +32,7 @@ pub fn encode<S: Into<String>>(value: S) -> String {
         let dangerous = value.pop().unwrap();
         result.push_str(&value);
         result.push_str(match dangerous {
+            '\0' => "�",
             '&' => "&amp;",
             '"' => "&quot;",
             '<' => "&lt;",
@@ -45,6 +47,10 @@ pub fn encode<S: Into<String>>(value: S) -> String {
     result
 }
 
-fn check(char: char) -> bool {
-    matches!(char, '&' | '"' | '<' | '>')
+fn check_all(char: char) -> bool {
+    matches!(char, '\0' | '&' | '"' | '<' | '>')
+}
+
+fn check_nil(char: char) -> bool {
+    matches!(char, '\0')
 }
diff --git a/src/util/mod.rs b/src/util/mod.rs
index ae1add6..a01f31e 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1,10 +1,9 @@
 //! Utilities used when compiling markdown.
 
-pub mod codes;
 pub mod decode_character_reference;
 pub mod edit_map;
 pub mod encode;
 pub mod normalize_identifier;
 pub mod sanitize_uri;
 pub mod skip;
-pub mod span;
+pub mod slice;
diff --git a/src/util/sanitize_uri.rs b/src/util/sanitize_uri.rs
index 81450ae..8c09549 100644
--- a/src/util/sanitize_uri.rs
+++ b/src/util/sanitize_uri.rs
@@ -32,7 +32,7 @@ use crate::util::encode::encode;
 ///
 /// *   [`micromark-util-sanitize-uri` in `micromark`](https://github.com/micromark/micromark/tree/main/packages/micromark-util-sanitize-uri)
 pub fn sanitize_uri(value: &str, protocols: &Option<Vec<&str>>) -> String {
-    let value = encode(normalize_uri(value));
+    let value = encode(normalize_uri(value), true);
 
     if let Some(protocols) = protocols {
         let end = value.find(|c| matches!(c, '?' | '#' | '/'));
diff --git a/src/util/slice.rs b/src/util/slice.rs
new file mode 100644
index 0000000..2134069
--- /dev/null
+++ b/src/util/slice.rs
@@ -0,0 +1,156 @@
+//! Utilities to deal with characters.
+
+use crate::constant::TAB_SIZE;
+use crate::tokenizer::{Event, EventType, Point};
+
+/// A range between two places.
+#[derive(Debug)]
+pub struct Position<'a> {
+    pub start: &'a Point,
+    pub end: &'a Point,
+}
+
+impl<'a> Position<'a> {
+    /// Get a position from an exit event.
+    ///
+    /// Looks backwards for the corresponding `enter` event.
+    /// This does not support nested events (such as lists in lists).
+    ///
+    /// ## Panics
+    ///
+    /// This function panics if an enter event is given.
+    /// When `micromark` is used, this function never panics.
+    pub fn from_exit_event(events: &'a [Event], index: usize) -> Position<'a> {
+        let exit = &events[index];
+        assert_eq!(
+            exit.event_type,
+            EventType::Exit,
+            "expected `from_exit_event` to be called on `exit` event"
+        );
+        let mut enter_index = index - 1;
+
+        loop {
+            let enter = &events[enter_index];
+            if enter.event_type == EventType::Enter && enter.token_type == exit.token_type {
+                return Position {
+                    start: &enter.point,
+                    end: &exit.point,
+                };
+            }
+
+            enter_index -= 1;
+        }
+    }
+}
+
+/// Chars belonging to a range.
+///
+/// Includes information on virtual spaces before and after the chars.
+#[derive(Debug)]
+pub struct Slice<'a> {
+    pub chars: &'a [char],
+    pub before: usize,
+    pub after: usize,
+}
+
+impl<'a> Slice<'a> {
+    /// Get the slice belonging to a position.
+    pub fn from_point(list: &'a [char], point: &Point) -> Slice<'a> {
+        let mut before = point.vs;
+        let mut start = point.index;
+        let end = if start < list.len() { start + 1 } else { start };
+
+        // If we have virtual spaces before, it means we are past the actual
+        // character at that index, and those virtual spaces.
+        if before > 0 {
+            before = TAB_SIZE - before;
+            start += 1;
+        };
+
+        Slice {
+            chars: if start < end { &list[start..end] } else { &[] },
+            before,
+            after: 0,
+        }
+    }
+
+    /// Get the slice belonging to a position.
+    pub fn from_position(list: &'a [char], position: &Position) -> Slice<'a> {
+        let mut before = position.start.vs;
+        let mut after = position.end.vs;
+        let mut start = position.start.index;
+        let mut end = position.end.index;
+
+        // If we have virtual spaces before, it means we are past the actual
+        // character at that index, and those virtual spaces.
+        if before > 0 {
+            before = TAB_SIZE - before;
+            start += 1;
+        };
+
+        // If we have virtual spaces after, it means that character is included,
+        // and one less virtual space.
+        if after > 0 {
+            after -= 1;
+            end += 1;
+        }
+
+        Slice {
+            chars: &list[start..end],
+            before,
+            after,
+        }
+    }
+
+    /// To do.
+    pub fn size(&self) -> usize {
+        self.chars.len() + self.before + self.after
+    }
+
+    // To do:
+    // When we have u8s, we could use: <https://doc.rust-lang.org/std/str/fn.from_utf8.html>
+    // to implement an `as_str`.
+
+    /// To do.
+    pub fn head(&self) -> Option<char> {
+        if self.before > 0 {
+            Some(' ')
+        } else if self.chars.is_empty() {
+            None
+        } else {
+            Some(self.chars[0])
+        }
+    }
+
+    /// To do.
+    pub fn tail(&self) -> Option<char> {
+        if self.after > 0 {
+            Some(' ')
+        } else {
+            let index = self.chars.len();
+            if index > 0 {
+                Some(self.chars[index - 1])
+            } else {
+                None
+            }
+        }
+    }
+
+    /// To do.
+    pub fn serialize(&self) -> String {
+        let mut string = String::with_capacity(self.size());
+        let mut index = self.before;
+        while index > 0 {
+            string.push(' ');
+            index -= 1;
+        }
+        string.push_str(&self.chars.iter().collect::<String>());
+        index = self.after;
+        while index > 0 {
+            string.push(' ');
+            index -= 1;
+        }
+
+        string
+    }
+}
diff --git a/src/util/span.rs b/src/util/span.rs
deleted file mode 100644
index ca25924..0000000
--- a/src/util/span.rs
+++ /dev/null
@@ -1,57 +0,0 @@
-//! Utilities to deal with semantic labels.
-
-use crate::tokenizer::{Code, Event, EventType};
-use crate::util::codes::serialize as serialize_codes;
-
-/// A struct representing the span of an opening and closing event of a token.
-#[derive(Debug)]
-pub struct Span {
-    /// Absolute offset (an `index` in `codes`) of where this span starts.
-    pub start_index: usize,
-    /// Absolute offset (an `index` in `codes`) of where this span ends.
-    pub end_index: usize,
-}
-
-/// Get a span from an event.
-///
-/// Get the span of an `exit` event, by looking backwards through the events to
-/// find the corresponding `enter` event.
-/// This assumes that tokens with the same are not nested.
-///
-/// ## Panics
-///
-/// This function panics if an enter event is given.
-/// When `micromark` is used, this function never panics.
-pub fn from_exit_event(events: &[Event], index: usize) -> Span {
-    let exit = &events[index];
-    let end_index = exit.point.index;
-    let token_type = exit.token_type.clone();
-    assert_eq!(
-        exit.event_type,
-        EventType::Exit,
-        "expected `from_exit_event` to be called on `exit` event"
-    );
-    let mut enter_index = index - 1;
-
-    loop {
-        let enter = &events[enter_index];
-        if enter.event_type == EventType::Enter && enter.token_type == token_type {
-            return Span {
-                start_index: enter.point.index,
-                end_index,
-            };
-        }
-
-        enter_index -= 1;
-    }
-}
-
-/// Serialize a span, optionally expanding tabs.
-pub fn serialize(all_codes: &[Code], span: &Span, expand_tabs: bool) -> String {
-    serialize_codes(codes(all_codes, span), expand_tabs)
-}
-
-/// Get a slice of codes from a span.
-pub fn codes<'a>(codes: &'a [Code], span: &Span) -> &'a [Code] {
-    &codes[span.start_index..span.end_index]
-}