Add text content type

*   Add character reference and character escapes in text
*   Add recursive subtokenization

8 files changed, 107 insertions, 24 deletions

diff --git a/readme.md b/readme.md
index cf42885..527170d 100644
--- a/readme.md
+++ b/readme.md
@@ -123,18 +123,18 @@ cargo doc --document-private-items
 - [ ] (8) container
   - [ ] block quote
   - [ ] list
-- [ ] (1) flow
+- [x] (1) flow
   - [x] blank line
   - [x] code (fenced)
   - [x] code (indented)
-  - [ ] content
+  - [x] content
   - [x] heading (atx)
   - [x] html (flow)
   - [x] thematic break
 - [ ] (3) content
   - [ ] definition
   - [ ] heading (setext)
-  - [ ] paragraph
+  - [x] paragraph
 - [ ] (5) text
   - [ ] attention (strong, emphasis) (text)
   - [ ] autolink
diff --git a/src/compiler.rs b/src/compiler.rs
index 05a56e1..48983b6 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -79,7 +79,6 @@ pub fn compile(events: &[Event], codes: &[Code], options: &CompileOptions) -> St
                 | TokenType::HtmlFlowData
                 | TokenType::CodeFencedFence
                 | TokenType::CodeFencedFenceSequence
-                | TokenType::ChunkText
                 | TokenType::CodeFencedFenceWhitespace
                 | TokenType::Data
                 | TokenType::CharacterEscape
@@ -280,8 +279,7 @@ pub fn compile(events: &[Event], codes: &[Code], options: &CompileOptions) -> St
                     character_reference_kind = None;
                 }
                 // This branch below currently acts as the resulting `data` tokens.
-                // To do: `ChunkText` does not belong here. Remove it when subtokenization is supported.
-                TokenType::ChunkText | TokenType::Data | TokenType::CharacterEscapeValue => {
+                TokenType::Data | TokenType::CharacterEscapeValue => {
                     // last_was_tag = false;
                     buf_tail_mut(buffers).push(encode(&slice_serialize(
                         codes,
diff --git a/src/content/flow.rs b/src/content/flow.rs
index 0d1bd22..6fa8c25 100644
--- a/src/content/flow.rs
+++ b/src/content/flow.rs
@@ -34,7 +34,11 @@ use crate::util::get_span;
 pub fn flow(codes: &[Code], point: Point, index: usize) -> Vec<Event> {
     let mut tokenizer = Tokenizer::new(point, index);
     tokenizer.feed(codes, Box::new(start), true);
-    subtokenize(tokenizer.events, codes)
+    let mut result = (tokenizer.events, false);
+    while !result.1 {
+        result = subtokenize(result.0, codes);
+    }
+    result.0
 }
 
 /// Before flow.
@@ -165,7 +169,7 @@ fn content_before(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
         }
         _ => {
             tokenizer.enter(TokenType::Content);
-            tokenizer.enter(TokenType::ContentChunk);
+            tokenizer.enter(TokenType::ChunkContent);
             content(tokenizer, code, tokenizer.events.len() - 1)
         }
     }
@@ -259,8 +263,8 @@ fn continuation_construct_after_prefix(tokenizer: &mut Tokenizer, code: Code) ->
 
 fn content_continue(tokenizer: &mut Tokenizer, code: Code, previous_index: usize) -> StateFnResult {
     tokenizer.consume(code);
-    tokenizer.exit(TokenType::ContentChunk);
-    tokenizer.enter(TokenType::ContentChunk);
+    tokenizer.exit(TokenType::ChunkContent);
+    tokenizer.enter(TokenType::ChunkContent);
     let next_index = tokenizer.events.len() - 1;
     tokenizer.events[previous_index].next = Some(next_index);
     tokenizer.events[next_index].previous = Some(previous_index);
@@ -271,7 +275,7 @@ fn content_continue(tokenizer: &mut Tokenizer, code: Code, previous_index: usize
 }
 
 fn content_end(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
-    tokenizer.exit(TokenType::ContentChunk);
+    tokenizer.exit(TokenType::ChunkContent);
     tokenizer.exit(TokenType::Content);
     after(tokenizer, code)
 }
diff --git a/src/content/mod.rs b/src/content/mod.rs
index 4c0a7f4..d13df79 100644
--- a/src/content/mod.rs
+++ b/src/content/mod.rs
@@ -4,3 +4,4 @@
 pub mod content;
 pub mod flow;
 pub mod string;
+pub mod text;
diff --git a/src/content/string.rs b/src/content/string.rs
index ff9e3fc..2723785 100644
--- a/src/content/string.rs
+++ b/src/content/string.rs
@@ -17,8 +17,6 @@ use crate::tokenizer::{Code, State, StateFnResult, TokenType, Tokenizer};
 
 /// Before string.
 ///
-/// First we assume character reference.
-///
 /// ```markdown
 /// |&amp;
 /// |\&
@@ -28,11 +26,7 @@ pub fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
     match code {
         Code::None => (State::Ok, None),
         _ => tokenizer.attempt_2(character_reference, character_escape, |ok| {
-            Box::new(if ok {
-                start
-            } else {
-                before_not_character_escape
-            })
+            Box::new(if ok { start } else { before_data })
         })(tokenizer, code),
     }
 }
@@ -44,7 +38,7 @@ pub fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
 /// ```markdown
 /// |qwe
 /// ```
-fn before_not_character_escape(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+fn before_data(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
     if let Code::None = code {
         (State::Ok, None)
     } else {
diff --git a/src/content/text.rs b/src/content/text.rs
new file mode 100644
index 0000000..2c93b18
--- /dev/null
+++ b/src/content/text.rs
@@ -0,0 +1,80 @@
+//! The text content type.
+//!
+//! **Text** contains phrasing content such as attention (emphasis, strong),
+//! media (links, images), and actual text.
+//!
+//! The constructs found in text are:
+//!
+//! *   Autolink
+//! *   Attention
+//! *   HTML (text)
+//! *   Hard break escape
+//! *   Code (text)
+//! *   Line ending
+//! *   Label start (image)
+//! *   Label start (link)
+//! *   [Character escape][crate::construct::character_escape]
+//! *   [Character reference][crate::construct::character_reference]
+
+use crate::construct::{
+    character_escape::start as character_escape, character_reference::start as character_reference,
+};
+use crate::tokenizer::{Code, State, StateFnResult, TokenType, Tokenizer};
+
+/// Before text.
+///
+/// First we assume character reference.
+///
+/// ```markdown
+/// |&amp;
+/// |\&
+/// |qwe
+/// ```
+pub fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+    match code {
+        Code::None => (State::Ok, None),
+        _ => tokenizer.attempt_2(character_reference, character_escape, |ok| {
+            Box::new(if ok { start } else { before_data })
+        })(tokenizer, code),
+    }
+}
+
+/// Before text.
+///
+/// We’re at data.
+///
+/// ```markdown
+/// |qwe
+/// ```
+fn before_data(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+    if let Code::None = code {
+        (State::Ok, None)
+    } else {
+        tokenizer.enter(TokenType::Data);
+        tokenizer.consume(code);
+        (State::Fn(Box::new(in_data)), None)
+    }
+}
+
+/// In data.
+///
+/// ```markdown
+/// q|w|e
+/// ```
+fn in_data(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+    match code {
+        Code::None => {
+            tokenizer.exit(TokenType::Data);
+            (State::Ok, None)
+        }
+        // To do: somehow get these markers from constructs.
+        Code::Char('&' | '\\') => {
+            tokenizer.exit(TokenType::Data);
+            start(tokenizer, code)
+        }
+        _ => {
+            tokenizer.consume(code);
+            (State::Fn(Box::new(in_data)), None)
+        }
+    }
+}
diff --git a/src/subtokenize.rs b/src/subtokenize.rs
index adf843f..d72eb69 100644
--- a/src/subtokenize.rs
+++ b/src/subtokenize.rs
@@ -1,37 +1,43 @@
 use crate::content::content::start as content;
 use crate::content::string::start as string;
+use crate::content::text::start as text;
 use crate::tokenizer::{
     Code, Event, EventType, State, StateFn, StateFnResult, TokenType, Tokenizer,
 };
 use crate::util::{slice_codes, Span};
 use std::collections::HashMap;
 
-pub fn subtokenize(events: Vec<Event>, codes: &[Code]) -> Vec<Event> {
+pub fn subtokenize(events: Vec<Event>, codes: &[Code]) -> (Vec<Event>, bool) {
     let mut events = events;
     let mut index = 0;
     // Map of first chunks its tokenizer.
     let mut head_to_tokenizer: HashMap<usize, Tokenizer> = HashMap::new();
     // Map of chunks to their head and corresponding range of events.
     let mut link_to_info: HashMap<usize, (usize, usize, usize)> = HashMap::new();
+    let mut done = true;
 
     while index < events.len() {
         let event = &events[index];
 
         // Find each first opening chunk.
         if (event.token_type == TokenType::ChunkString
-                || event.token_type == TokenType::ContentChunk) &&
+                || event.token_type == TokenType::ChunkText
+                || event.token_type == TokenType::ChunkContent) &&
             event.event_type == EventType::Enter &&
             // No need to enter linked events again.
             event.previous == None
         {
+            done = false;
             // Index into `events` pointing to a chunk.
             let mut index_opt: Option<usize> = Some(index);
             // Subtokenizer.
             let mut tokenizer = Tokenizer::new(event.point.clone(), event.index);
             // Substate.
             let mut result: StateFnResult = (
-                State::Fn(Box::new(if event.token_type == TokenType::ContentChunk {
+                State::Fn(Box::new(if event.token_type == TokenType::ChunkContent {
                     content
+                } else if event.token_type == TokenType::ChunkText {
+                    text
                 } else {
                     string
                 })),
@@ -129,5 +135,5 @@ pub fn subtokenize(events: Vec<Event>, codes: &[Code]) -> Vec<Event> {
         index -= 1;
     }
 
-    events
+    (events, done)
 }
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 1746a19..4d235ed 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -63,10 +63,10 @@ pub enum TokenType {
     BlankLineWhitespace,
 
     Content,
-    ContentChunk,
 
     Paragraph,
 
+    ChunkContent,
     ChunkString,
     ChunkText,
 }