Add support for math (flow)

1 files changed, 665 insertions, 0 deletions

diff --git a/src/construct/raw_flow.rs b/src/construct/raw_flow.rs
new file mode 100644
index 0000000..7eaac0c
--- /dev/null
+++ b/src/construct/raw_flow.rs
@@ -0,0 +1,665 @@
+//! Raw (flow) occurs in the [flow][] content type.
+//! It forms code (fenced) and math (flow).
+//!
+//! ## Grammar
+//!
+//! Code (fenced) forms with the following BNF
+//! (<small>see [construct][crate::construct] for character groups</small>):
+//!
+//! ```bnf
+//! raw_flow ::= fence_open *( eol *byte ) [ eol fence_close ]
+//!
+//! ; Restriction: math (flow) does not support the `info` part.
+//! fence_open ::= sequence [1*space_or_tab info [1*space_or_tab meta]] *space_or_tab
+//! ; Restriction: the number of markers in the closing fence sequence must be
+//! ; equal to or greater than the number of markers in the opening fence
+//! ; sequence.
+//! ; Restriction: the marker in the closing fence sequence must match the
+//! ; marker in the opening fence sequence
+//! fence_close ::= sequence *space_or_tab
+//! sequence ::= 3*'`' | 3*'~' | 2*'$'
+//! ; Restriction: the marker cannot occur in `info` if it is the `$` or `` ` `` character.
+//! info ::= 1*text
+//! ; Restriction: the marker cannot occur in `meta` if it is the `$` or `` ` `` character.
+//! meta ::= 1*text *(*space_or_tab 1*text)
+//! ```
+//!
+//! As this construct occurs in flow, like all flow constructs, it must be
+//! followed by an eol (line ending) or eof (end of file).
+//!
+//! The above grammar does not show how indentation (with `space_or_tab`) of
+//! each line is handled.
+//! To parse raw (flow), let `x` be the number of `space_or_tab` characters
+//! before the opening fence sequence.
+//! Each line of text is then allowed (not required) to be indented with up
+//! to `x` spaces or tabs, which are then ignored as an indent instead of being
+//! considered as part of the content.
+//! This indent does not affect the closing fence.
+//! It can be indented up to a separate 3 spaces or tabs.
+//! A bigger indent makes it part of the content instead of a fence.
+//!
+//! The `info` and `meta` parts are interpreted as the [string][] content type.
+//! That means that [character escapes][character_escape] and
+//! [character references][character_reference] are allowed.
+//! Math (flow) does not support `info`.
+//!
+//! The optional `meta` part is ignored: it is not used when parsing or
+//! rendering.
+//!
+//! The optional `info` part is used and is expected to specify the programming
+//! language that the content is in.
+//! Which value it holds depends on what your syntax highlighter supports, if
+//! one is used.
+//!
+//! In markdown, it is also possible to use [raw (text)][raw_text] in the
+//! [text][] content type.
+//! It is also possible to create code with the
+//! [code (indented)][code_indented] construct.
+//!
+//! ## HTML
+//!
+//! Code (fenced) relates to both the `<pre>` and the `<code>` elements in
+//! HTML.
+//! See [*§ 4.4.3 The `pre` element*][html_pre] and the [*§ 4.5.15 The `code`
+//! element*][html_code] in the HTML spec for more info.
+//!
+//! Math (flow) does not relate to HTML elements.
+//! `MathML`, which is sort of like SVG but for math, exists but it doesn’t work
+//! well and isn’t widely supported.
+//! Instead, it is recommended to use client side JavaScript with something like
+//! `KaTeX` or `MathJax` to process the math
+//! For that, the math is compiled as a `<pre>`, and a `<code>` element with two
+//! classes: `language-math` and `math-display`.
+//! Client side JavaScript can look for these classes to process them further.
+//!
+//! The `info` is, when rendering to HTML, typically exposed as a class.
+//! This behavior stems from the HTML spec ([*§ 4.5.15 The `code`
+//! element*][html_code]).
+//! For example:
+//!
+//! ```markdown
+//! ~~~css
+//! * { color: tomato }
+//! ~~~
+//! ```
+//!
+//! Yields:
+//!
+//! ```html
+//! <pre><code class="language-css">* { color: tomato }
+//! </code></pre>
+//! ```
+//!
+//! ## Recommendation
+//!
+//! It is recommended to use code (fenced) instead of code (indented).
+//! Code (fenced) is more explicit, similar to code (text), and has support
+//! for specifying the programming language.
+//!
+//! When authoring markdown with math, keep in mind that math doesn’t work in
+//! most places.
+//! Notably, GitHub currently has a really weird crappy client-side regex-based
+//! thing.
+//! But on your own (math-heavy?) site it can be great!
+//! You can use code (fenced) with an info string of `math` to improve this, as
+//! that works in many places.
+//!
+//! ## Tokens
+//!
+//! *   [`CodeFenced`][Name::CodeFenced]
+//! *   [`CodeFencedFence`][Name::CodeFencedFence]
+//! *   [`CodeFencedFenceInfo`][Name::CodeFencedFenceInfo]
+//! *   [`CodeFencedFenceMeta`][Name::CodeFencedFenceMeta]
+//! *   [`CodeFencedFenceSequence`][Name::CodeFencedFenceSequence]
+//! *   [`CodeFlowChunk`][Name::CodeFlowChunk]
+//! *   [`LineEnding`][Name::LineEnding]
+//! *   [`MathFlow`][Name::MathFlow]
+//! *   [`MathFlowFence`][Name::MathFlowFence]
+//! *   [`MathFlowFenceMeta`][Name::MathFlowFenceMeta]
+//! *   [`MathFlowFenceSequence`][Name::MathFlowFenceSequence]
+//! *   [`MathFlowChunk`][Name::MathFlowChunk]
+//! *   [`SpaceOrTab`][Name::SpaceOrTab]
+//!
+//! ## References
+//!
+//! *   [`code-fenced.js` in `micromark`](https://github.com/micromark/micromark/blob/main/packages/micromark-core-commonmark/dev/lib/code-fenced.js)
+//! *   [`micromark-extension-math`](https://github.com/micromark/micromark-extension-math)
+//! *   [*§ 4.5 Fenced code blocks* in `CommonMark`](https://spec.commonmark.org/0.30/#fenced-code-blocks)
+//!
+//! > 👉 **Note**: math is not specified anywhere.
+//!
+//! [flow]: crate::construct::flow
+//! [string]: crate::construct::string
+//! [text]: crate::construct::text
+//! [character_escape]: crate::construct::character_escape
+//! [character_reference]: crate::construct::character_reference
+//! [code_indented]: crate::construct::code_indented
+//! [raw_text]: crate::construct::raw_text
+//! [html_code]: https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-code-element
+//! [html_pre]: https://html.spec.whatwg.org/multipage/grouping-content.html#the-pre-element
+
+use crate::construct::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
+use crate::event::{Content, Link, Name};
+use crate::state::{Name as StateName, State};
+use crate::tokenizer::Tokenizer;
+use crate::util::{
+    constant::{CODE_FENCED_SEQUENCE_SIZE_MIN, TAB_SIZE},
+    slice::{Position, Slice},
+};
+
+/// Start of raw.
+///
+/// ```markdown
+/// > | ~~~js
+///     ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn start(tokenizer: &mut Tokenizer) -> State {
+    if tokenizer.parse_state.options.constructs.code_fenced
+        || tokenizer.parse_state.options.constructs.math_flow
+    {
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.attempt(
+                State::Next(StateName::RawFlowBeforeSequenceOpen),
+                State::Nok,
+            );
+            return State::Retry(space_or_tab_min_max(
+                tokenizer,
+                0,
+                if tokenizer.parse_state.options.constructs.code_indented {
+                    TAB_SIZE - 1
+                } else {
+                    usize::MAX
+                },
+            ));
+        }
+
+        if matches!(tokenizer.current, Some(b'$' | b'`' | b'~')) {
+            return State::Retry(StateName::RawFlowBeforeSequenceOpen);
+        }
+    }
+
+    State::Nok
+}
+
+/// In opening fence, after prefix, at sequence.
+///
+/// ```markdown
+/// > | ~~~js
+///     ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn before_sequence_open(tokenizer: &mut Tokenizer) -> State {
+    let tail = tokenizer.events.last();
+    let mut prefix = 0;
+
+    if let Some(event) = tail {
+        if event.name == Name::SpaceOrTab {
+            prefix = Slice::from_position(
+                tokenizer.parse_state.bytes,
+                &Position::from_exit_event(&tokenizer.events, tokenizer.events.len() - 1),
+            )
+            .len();
+        }
+    }
+
+    // Code (fenced).
+    if (tokenizer.parse_state.options.constructs.code_fenced
+        && matches!(tokenizer.current, Some(b'`' | b'~')))
+        // Math (flow).
+        || (tokenizer.parse_state.options.constructs.math_flow && tokenizer.current == Some(b'$'))
+    {
+        tokenizer.tokenize_state.marker = tokenizer.current.unwrap();
+        tokenizer.tokenize_state.size_c = prefix;
+        if tokenizer.tokenize_state.marker == b'$' {
+            tokenizer.tokenize_state.token_1 = Name::MathFlow;
+            tokenizer.tokenize_state.token_2 = Name::MathFlowFence;
+            tokenizer.tokenize_state.token_3 = Name::MathFlowFenceSequence;
+            // Math (flow) does not support an `info` part: everything after the
+            // opening sequence is the `meta` part.
+            tokenizer.tokenize_state.token_5 = Name::MathFlowFenceMeta;
+            tokenizer.tokenize_state.token_6 = Name::MathFlowChunk;
+        } else {
+            tokenizer.tokenize_state.token_1 = Name::CodeFenced;
+            tokenizer.tokenize_state.token_2 = Name::CodeFencedFence;
+            tokenizer.tokenize_state.token_3 = Name::CodeFencedFenceSequence;
+            tokenizer.tokenize_state.token_4 = Name::CodeFencedFenceInfo;
+            tokenizer.tokenize_state.token_5 = Name::CodeFencedFenceMeta;
+            tokenizer.tokenize_state.token_6 = Name::CodeFlowChunk;
+        }
+
+        tokenizer.enter(tokenizer.tokenize_state.token_1.clone());
+        tokenizer.enter(tokenizer.tokenize_state.token_2.clone());
+        tokenizer.enter(tokenizer.tokenize_state.token_3.clone());
+        State::Retry(StateName::RawFlowSequenceOpen)
+    } else {
+        State::Nok
+    }
+}
+
+/// In opening fence sequence.
+///
+/// ```markdown
+/// > | ~~~js
+///      ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn sequence_open(tokenizer: &mut Tokenizer) -> State {
+    if tokenizer.current == Some(tokenizer.tokenize_state.marker) {
+        tokenizer.tokenize_state.size += 1;
+        tokenizer.consume();
+        State::Next(StateName::RawFlowSequenceOpen)
+    }
+    // To do: constant.
+    else if tokenizer.tokenize_state.size
+        < (if tokenizer.tokenize_state.marker == b'$' {
+            2
+        } else {
+            CODE_FENCED_SEQUENCE_SIZE_MIN
+        })
+    {
+        tokenizer.tokenize_state.marker = 0;
+        tokenizer.tokenize_state.size_c = 0;
+        tokenizer.tokenize_state.size = 0;
+        tokenizer.tokenize_state.token_1 = Name::Data;
+        tokenizer.tokenize_state.token_2 = Name::Data;
+        tokenizer.tokenize_state.token_3 = Name::Data;
+        tokenizer.tokenize_state.token_4 = Name::Data;
+        tokenizer.tokenize_state.token_5 = Name::Data;
+        tokenizer.tokenize_state.token_6 = Name::Data;
+        State::Nok
+    } else {
+        // Math (flow) does not support an `info` part: everything after the
+        // opening sequence is the `meta` part.
+        let next = if tokenizer.tokenize_state.marker == b'$' {
+            StateName::RawFlowMetaBefore
+        } else {
+            StateName::RawFlowInfoBefore
+        };
+
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.exit(tokenizer.tokenize_state.token_3.clone());
+            tokenizer.attempt(State::Next(next), State::Nok);
+            State::Retry(space_or_tab(tokenizer))
+        } else {
+            tokenizer.exit(tokenizer.tokenize_state.token_3.clone());
+            State::Retry(next)
+        }
+    }
+}
+
+/// In opening fence, after the sequence (and optional whitespace), before info.
+///
+/// ```markdown
+/// > | ~~~js
+///        ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn info_before(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.exit(tokenizer.tokenize_state.token_2.clone());
+            // Do not form containers.
+            tokenizer.concrete = true;
+            tokenizer.check(
+                State::Next(StateName::RawFlowAtNonLazyBreak),
+                State::Next(StateName::RawFlowAfter),
+            );
+            State::Retry(StateName::NonLazyContinuationStart)
+        }
+        _ => {
+            tokenizer.enter(tokenizer.tokenize_state.token_4.clone());
+            tokenizer.enter_link(
+                Name::Data,
+                Link {
+                    previous: None,
+                    next: None,
+                    content: Content::String,
+                },
+            );
+            State::Retry(StateName::RawFlowInfo)
+        }
+    }
+}
+
+/// In info.
+///
+/// ```markdown
+/// > | ~~~js
+///        ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn info(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.exit(Name::Data);
+            tokenizer.exit(tokenizer.tokenize_state.token_4.clone());
+            State::Retry(StateName::RawFlowInfoBefore)
+        }
+        Some(b'\t' | b' ') => {
+            tokenizer.exit(Name::Data);
+            tokenizer.exit(tokenizer.tokenize_state.token_4.clone());
+            tokenizer.attempt(State::Next(StateName::RawFlowMetaBefore), State::Nok);
+            State::Retry(space_or_tab(tokenizer))
+        }
+        Some(byte) => {
+            // This looks like code (text) / math (text).
+            // Note: no reason to check for `~`, because 3 of them can‘t be
+            // used as strikethrough in text.
+            if tokenizer.tokenize_state.marker == byte && matches!(byte, b'$' | b'`') {
+                tokenizer.concrete = false;
+                tokenizer.tokenize_state.marker = 0;
+                tokenizer.tokenize_state.size_c = 0;
+                tokenizer.tokenize_state.size = 0;
+                tokenizer.tokenize_state.token_1 = Name::Data;
+                tokenizer.tokenize_state.token_2 = Name::Data;
+                tokenizer.tokenize_state.token_3 = Name::Data;
+                tokenizer.tokenize_state.token_4 = Name::Data;
+                tokenizer.tokenize_state.token_5 = Name::Data;
+                tokenizer.tokenize_state.token_6 = Name::Data;
+                State::Nok
+            } else {
+                tokenizer.consume();
+                State::Next(StateName::RawFlowInfo)
+            }
+        }
+    }
+}
+
+/// In opening fence, after info and whitespace, before meta.
+///
+/// ```markdown
+/// > | ~~~js eval
+///           ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn meta_before(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => State::Retry(StateName::RawFlowInfoBefore),
+        _ => {
+            tokenizer.enter(tokenizer.tokenize_state.token_5.clone());
+            tokenizer.enter_link(
+                Name::Data,
+                Link {
+                    previous: None,
+                    next: None,
+                    content: Content::String,
+                },
+            );
+            State::Retry(StateName::RawFlowMeta)
+        }
+    }
+}
+
+/// In meta.
+///
+/// ```markdown
+/// > | ~~~js eval
+///           ^
+///   | console.log(1)
+///   | ~~~
+/// ```
+pub fn meta(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.exit(Name::Data);
+            tokenizer.exit(tokenizer.tokenize_state.token_5.clone());
+            State::Retry(StateName::RawFlowInfoBefore)
+        }
+        Some(byte) => {
+            // This looks like code (text) / math (text).
+            // Note: no reason to check for `~`, because 3 of them can‘t be
+            // used as strikethrough in text.
+            if tokenizer.tokenize_state.marker == byte && matches!(byte, b'$' | b'`') {
+                tokenizer.concrete = false;
+                tokenizer.tokenize_state.marker = 0;
+                tokenizer.tokenize_state.size_c = 0;
+                tokenizer.tokenize_state.size = 0;
+                tokenizer.tokenize_state.token_1 = Name::Data;
+                tokenizer.tokenize_state.token_2 = Name::Data;
+                tokenizer.tokenize_state.token_3 = Name::Data;
+                tokenizer.tokenize_state.token_4 = Name::Data;
+                tokenizer.tokenize_state.token_5 = Name::Data;
+                tokenizer.tokenize_state.token_6 = Name::Data;
+                State::Nok
+            } else {
+                tokenizer.consume();
+                State::Next(StateName::RawFlowMeta)
+            }
+        }
+    }
+}
+
+/// At eol/eof in code, before a non-lazy closing fence or content.
+///
+/// ```markdown
+/// > | ~~~js
+///          ^
+/// > | console.log(1)
+///                   ^
+///   | ~~~
+/// ```
+pub fn at_non_lazy_break(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.attempt(
+        State::Next(StateName::RawFlowAfter),
+        State::Next(StateName::RawFlowContentBefore),
+    );
+    tokenizer.enter(Name::LineEnding);
+    tokenizer.consume();
+    tokenizer.exit(Name::LineEnding);
+    State::Next(StateName::RawFlowCloseStart)
+}
+
+/// Before closing fence, at optional whitespace.
+///
+/// ```markdown
+///   | ~~~js
+///   | console.log(1)
+/// > | ~~~
+///     ^
+/// ```
+pub fn close_start(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.enter(tokenizer.tokenize_state.token_2.clone());
+
+    if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+        tokenizer.attempt(
+            State::Next(StateName::RawFlowBeforeSequenceClose),
+            State::Nok,
+        );
+
+        State::Retry(space_or_tab_min_max(
+            tokenizer,
+            0,
+            if tokenizer.parse_state.options.constructs.code_indented {
+                TAB_SIZE - 1
+            } else {
+                usize::MAX
+            },
+        ))
+    } else {
+        State::Retry(StateName::RawFlowBeforeSequenceClose)
+    }
+}
+
+/// In closing fence, after optional whitespace, at sequence.
+///
+/// ```markdown
+///   | ~~~js
+///   | console.log(1)
+/// > | ~~~
+///     ^
+/// ```
+pub fn before_sequence_close(tokenizer: &mut Tokenizer) -> State {
+    if tokenizer.current == Some(tokenizer.tokenize_state.marker) {
+        tokenizer.enter(tokenizer.tokenize_state.token_3.clone());
+        State::Retry(StateName::RawFlowSequenceClose)
+    } else {
+        State::Nok
+    }
+}
+
+/// In closing fence sequence.
+///
+/// ```markdown
+///   | ~~~js
+///   | console.log(1)
+/// > | ~~~
+///     ^
+/// ```
+pub fn sequence_close(tokenizer: &mut Tokenizer) -> State {
+    if tokenizer.current == Some(tokenizer.tokenize_state.marker) {
+        tokenizer.tokenize_state.size_b += 1;
+        tokenizer.consume();
+        State::Next(StateName::RawFlowSequenceClose)
+    } else if tokenizer.tokenize_state.size_b >= tokenizer.tokenize_state.size {
+        tokenizer.tokenize_state.size_b = 0;
+        tokenizer.exit(tokenizer.tokenize_state.token_3.clone());
+
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.attempt(
+                State::Next(StateName::RawFlowAfterSequenceClose),
+                State::Nok,
+            );
+            State::Retry(space_or_tab(tokenizer))
+        } else {
+            State::Retry(StateName::RawFlowAfterSequenceClose)
+        }
+    } else {
+        tokenizer.tokenize_state.size_b = 0;
+        State::Nok
+    }
+}
+
+/// After closing fence sequence, after optional whitespace.
+///
+/// ```markdown
+///   | ~~~js
+///   | console.log(1)
+/// > | ~~~
+///        ^
+/// ```
+pub fn sequence_close_after(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.exit(tokenizer.tokenize_state.token_2.clone());
+            State::Ok
+        }
+        _ => State::Nok,
+    }
+}
+
+/// Before closing fence, at eol.
+///
+/// ```markdown
+///   | ~~~js
+/// > | console.log(1)
+///                   ^
+///   | ~~~
+/// ```
+pub fn content_before(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.enter(Name::LineEnding);
+    tokenizer.consume();
+    tokenizer.exit(Name::LineEnding);
+    State::Next(StateName::RawFlowContentStart)
+}
+
+/// Before code content, definitely not before a closing fence.
+///
+/// ```markdown
+///   | ~~~js
+/// > | console.log(1)
+///     ^
+///   | ~~~
+/// ```
+pub fn content_start(tokenizer: &mut Tokenizer) -> State {
+    if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+        tokenizer.attempt(
+            State::Next(StateName::RawFlowBeforeContentChunk),
+            State::Nok,
+        );
+        State::Retry(space_or_tab_min_max(
+            tokenizer,
+            0,
+            tokenizer.tokenize_state.size_c,
+        ))
+    } else {
+        State::Retry(StateName::RawFlowBeforeContentChunk)
+    }
+}
+
+/// Before code content, after optional prefix.
+///
+/// ```markdown
+///   | ~~~js
+/// > | console.log(1)
+///     ^
+///   | ~~~
+/// ```
+pub fn before_content_chunk(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.check(
+                State::Next(StateName::RawFlowAtNonLazyBreak),
+                State::Next(StateName::RawFlowAfter),
+            );
+            State::Retry(StateName::NonLazyContinuationStart)
+        }
+        _ => {
+            tokenizer.enter(tokenizer.tokenize_state.token_6.clone());
+            State::Retry(StateName::RawFlowContentChunk)
+        }
+    }
+}
+
+/// In code content.
+///
+/// ```markdown
+///   | ~~~js
+/// > | console.log(1)
+///     ^^^^^^^^^^^^^^
+///   | ~~~
+/// ```
+pub fn content_chunk(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        None | Some(b'\n') => {
+            tokenizer.exit(tokenizer.tokenize_state.token_6.clone());
+            State::Retry(StateName::RawFlowBeforeContentChunk)
+        }
+        _ => {
+            tokenizer.consume();
+            State::Next(StateName::RawFlowContentChunk)
+        }
+    }
+}
+
+/// After raw.
+///
+/// ```markdown
+///   | ~~~js
+///   | console.log(1)
+/// > | ~~~
+///        ^
+/// ```
+pub fn after(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.exit(tokenizer.tokenize_state.token_1.clone());
+    tokenizer.tokenize_state.marker = 0;
+    tokenizer.tokenize_state.size_c = 0;
+    tokenizer.tokenize_state.size = 0;
+    tokenizer.tokenize_state.token_1 = Name::Data;
+    tokenizer.tokenize_state.token_2 = Name::Data;
+    tokenizer.tokenize_state.token_3 = Name::Data;
+    tokenizer.tokenize_state.token_4 = Name::Data;
+    tokenizer.tokenize_state.token_5 = Name::Data;
+    tokenizer.tokenize_state.token_6 = Name::Data;
+    // Feel free to interrupt.
+    tokenizer.interrupt = false;
+    // No longer concrete.
+    tokenizer.concrete = false;
+    State::Ok
+}