Refactor to move `space_or_tab_eol` to own file

1 files changed, 174 insertions, 0 deletions

diff --git a/src/construct/partial_space_or_tab_eol.rs b/src/construct/partial_space_or_tab_eol.rs
new file mode 100644
index 0000000..0807a5f
--- /dev/null
+++ b/src/construct/partial_space_or_tab_eol.rs
@@ -0,0 +1,174 @@
+//! Several helpers to parse whitespace (`space_or_tab`, `space_or_tab_eol`).
+//!
+//! ## References
+//!
+//! *   [`micromark-factory-space/index.js` in `micromark`](https://github.com/micromark/micromark/blob/main/packages/micromark-factory-space/dev/index.js)
+
+use crate::construct::partial_space_or_tab::{
+    space_or_tab_with_options, Options as SpaceOrTabOptions,
+};
+use crate::event::{Content, Name};
+use crate::state::{Name as StateName, State};
+use crate::subtokenize::link;
+use crate::tokenizer::Tokenizer;
+
+/// Options to parse `space_or_tab` and one optional eol, but no blank line.
+#[derive(Debug)]
+pub struct Options {
+    /// Connect this whitespace to the previous.
+    pub connect: bool,
+    /// Embedded content type to use.
+    pub content_type: Option<Content>,
+}
+
+/// `space_or_tab`, or optionally `space_or_tab`, one `eol`, and
+/// optionally `space_or_tab`.
+///
+/// ```bnf
+/// space_or_tab_eol ::= 1*( ' ' '\t' ) | 0*( ' ' '\t' ) eol 0*( ' ' '\t' )
+/// ```
+pub fn space_or_tab_eol(tokenizer: &mut Tokenizer) -> StateName {
+    space_or_tab_eol_with_options(
+        tokenizer,
+        Options {
+            content_type: None,
+            connect: false,
+        },
+    )
+}
+
+/// `space_or_tab_eol`, with the given options.
+pub fn space_or_tab_eol_with_options(tokenizer: &mut Tokenizer, options: Options) -> StateName {
+    tokenizer.tokenize_state.space_or_tab_eol_content_type = options.content_type;
+    tokenizer.tokenize_state.space_or_tab_eol_connect = options.connect;
+    StateName::SpaceOrTabEolStart
+}
+
+pub fn eol_start(tokenizer: &mut Tokenizer) -> State {
+    let name = space_or_tab_with_options(
+        tokenizer,
+        SpaceOrTabOptions {
+            kind: Name::SpaceOrTab,
+            min: 1,
+            max: usize::MAX,
+            content_type: tokenizer
+                .tokenize_state
+                .space_or_tab_eol_content_type
+                .clone(),
+            connect: tokenizer.tokenize_state.space_or_tab_eol_connect,
+        },
+    );
+
+    tokenizer.attempt(
+        name,
+        State::Next(StateName::SpaceOrTabEolAfterFirst),
+        State::Next(StateName::SpaceOrTabEolAtEol),
+    )
+}
+
+pub fn eol_after_first(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.tokenize_state.space_or_tab_eol_ok = true;
+
+    if tokenizer
+        .tokenize_state
+        .space_or_tab_eol_content_type
+        .is_some()
+    {
+        tokenizer.tokenize_state.space_or_tab_eol_connect = true;
+    }
+
+    State::Retry(StateName::SpaceOrTabEolAtEol)
+}
+
+/// `space_or_tab_eol`: after optionally first `space_or_tab`.
+///
+/// ```markdown
+/// > | a
+///      ^
+///   | b
+/// ```
+pub fn eol_at_eol(tokenizer: &mut Tokenizer) -> State {
+    if let Some(b'\n') = tokenizer.current {
+        tokenizer.enter_with_content(
+            Name::LineEnding,
+            tokenizer
+                .tokenize_state
+                .space_or_tab_eol_content_type
+                .clone(),
+        );
+
+        if tokenizer.tokenize_state.space_or_tab_eol_connect {
+            let index = tokenizer.events.len() - 1;
+            link(&mut tokenizer.events, index);
+        } else if tokenizer
+            .tokenize_state
+            .space_or_tab_eol_content_type
+            .is_some()
+        {
+            tokenizer.tokenize_state.space_or_tab_eol_connect = true;
+        }
+
+        tokenizer.consume();
+        tokenizer.exit(Name::LineEnding);
+        State::Next(StateName::SpaceOrTabEolAfterEol)
+    } else {
+        let ok = tokenizer.tokenize_state.space_or_tab_eol_ok;
+        tokenizer.tokenize_state.space_or_tab_eol_content_type = None;
+        tokenizer.tokenize_state.space_or_tab_eol_connect = false;
+        tokenizer.tokenize_state.space_or_tab_eol_ok = false;
+        if ok {
+            State::Ok
+        } else {
+            State::Nok
+        }
+    }
+}
+
+/// `space_or_tab_eol`: after eol.
+///
+/// ```markdown
+///   | a
+/// > | b
+///     ^
+/// ```
+#[allow(clippy::needless_pass_by_value)]
+pub fn eol_after_eol(tokenizer: &mut Tokenizer) -> State {
+    let name = space_or_tab_with_options(
+        tokenizer,
+        SpaceOrTabOptions {
+            kind: Name::SpaceOrTab,
+            min: 1,
+            max: usize::MAX,
+            content_type: tokenizer
+                .tokenize_state
+                .space_or_tab_eol_content_type
+                .clone(),
+            connect: tokenizer.tokenize_state.space_or_tab_eol_connect,
+        },
+    );
+    tokenizer.attempt(
+        name,
+        State::Next(StateName::SpaceOrTabEolAfterMore),
+        State::Next(StateName::SpaceOrTabEolAfterMore),
+    )
+}
+
+/// `space_or_tab_eol`: after more (optional) `space_or_tab`.
+///
+/// ```markdown
+///   | a
+/// > | b
+///     ^
+/// ```
+pub fn eol_after_more(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.tokenize_state.space_or_tab_eol_content_type = None;
+    tokenizer.tokenize_state.space_or_tab_eol_connect = false;
+    tokenizer.tokenize_state.space_or_tab_eol_ok = false;
+
+    // Blank line not allowed.
+    if matches!(tokenizer.current, None | Some(b'\n')) {
+        State::Nok
+    } else {
+        State::Ok
+    }
+}