1 files changed, 84 insertions, 0 deletions
diff --git a/src/construct/mdx_expression_flow.rs b/src/construct/mdx_expression_flow.rs
new file mode 100644
index 0000000..0faea31
--- /dev/null
+++ b/src/construct/mdx_expression_flow.rs
@@ -0,0 +1,84 @@
+//! To do.
+
+use crate::construct::partial_space_or_tab::{space_or_tab, space_or_tab_min_max};
+use crate::event::Name;
+use crate::state::{Name as StateName, State};
+use crate::tokenizer::Tokenizer;
+use crate::util::constant::TAB_SIZE;
+
+/// Start of MDX: expression (flow).
+///
+/// ```markdown
+/// > | {Math.PI}
+///     ^
+/// ```
+pub fn start(tokenizer: &mut Tokenizer) -> State {
+    if tokenizer.parse_state.options.constructs.mdx_expression_flow {
+        tokenizer.tokenize_state.token_1 = Name::MdxFlowExpression;
+        tokenizer.concrete = true;
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.attempt(State::Next(StateName::MdxExpressionFlowBefore), 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::MdxExpressionFlowBefore)
+        }
+    } else {
+        State::Nok
+    }
+}
+
+/// After optional whitespace, before of MDX expression (flow).
+///
+/// ```markdown
+/// > | {Math.PI}
+///     ^
+/// ```
+pub fn before(tokenizer: &mut Tokenizer) -> State {
+    if Some(b'{') == tokenizer.current {
+        tokenizer.attempt(State::Next(StateName::MdxExpressionFlowAfter), State::Nok);
+        State::Retry(StateName::MdxExpressionStart)
+    } else {
+        State::Nok
+    }
+}
+
+/// After an MDX expression (flow).
+///
+/// ```markdown
+/// > | {Math.PI}
+///              ^
+/// ```
+pub fn after(tokenizer: &mut Tokenizer) -> State {
+    match tokenizer.current {
+        Some(b'\t' | b' ') => {
+            tokenizer.attempt(State::Next(StateName::MdxExpressionFlowEnd), State::Nok);
+            State::Retry(space_or_tab(tokenizer))
+        }
+        _ => State::Retry(StateName::MdxExpressionFlowEnd),
+    }
+}
+
+/// After an MDX expression (flow), after optional whitespace.
+///
+/// ```markdown
+/// > | {Math.PI}␠␊
+///               ^
+/// ```
+pub fn end(tokenizer: &mut Tokenizer) -> State {
+    tokenizer.concrete = false;
+    tokenizer.tokenize_state.token_1 = Name::Data;
+
+    if matches!(tokenizer.current, None | Some(b'\n')) {
+        State::Ok
+    } else {
+        State::Nok
+    }
+}