Switch subscript and superscript to using bracket depth from OrgSource instead of from the context.

This is for the same reasons as footnote references.

src/parser/parser_context.rs

@@ -149,18 +149,6 @@ pub enum ContextElement<'r, 's> {
     /// unbalanced brackets can be detected in the middle of an
     /// object.
     InlineSourceBlockBracket(InlineSourceBlockBracket<'s>),
-
-    /// Stores the current bracket or parenthesis depth inside a
-    /// superscript or superscript.
-    ///
-    /// Inside the braces of a subscript or superscript there must be
-    /// balanced braces {}, so this stores the amount of opening
-    /// braces subtracted by the amount of closing braces within the
-    /// definition must equal zero.
-    ///
-    /// A reference to the position in the string is also included so
-    /// unbalanced braces can be detected in the middle of an object.
-    SubscriptSuperscriptBrace(SubscriptSuperscriptBrace<'s>),
 }
 
 pub struct ExitMatcherNode<'r> {
@@ -180,12 +168,6 @@ pub struct InlineSourceBlockBracket<'s> {
     pub depth: usize,
 }
 
-#[derive(Debug)]
-pub struct SubscriptSuperscriptBrace<'s> {
-    pub position: OrgSource<'s>,
-    pub depth: usize,
-}
-
 impl<'r> std::fmt::Debug for ExitMatcherNode<'r> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let mut formatter = f.debug_struct("ExitMatcherNode");

src/parser/subscript_and_superscript.rs

@@ -21,7 +21,6 @@ use crate::parser::exiting::ExitClass;
 use crate::parser::object_parser::standard_set_object;
 use crate::parser::parser_context::ContextElement;
 use crate::parser::parser_context::ExitMatcherNode;
-use crate::parser::parser_context::SubscriptSuperscriptBrace;
 use crate::parser::parser_with_context::parser_with_context;
 use crate::parser::util::exit_matcher_parser;
 use crate::parser::util::get_consumed;
@@ -154,16 +153,11 @@ fn script_with_braces<'r, 's>(
     input: OrgSource<'s>,
 ) -> Res<OrgSource<'s>, Vec<Object<'s>>> {
     let (remaining, _) = tag("{")(input)?;
-    let parser_context = context
-        .with_additional_node(ContextElement::SubscriptSuperscriptBrace(
-            SubscriptSuperscriptBrace {
-                position: remaining.into(),
-                depth: 0,
-            },
-        ))
-        .with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
+    let exit_with_depth = script_with_braces_end(remaining.get_brace_depth());
+    let parser_context =
+        context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
             class: ExitClass::Gamma,
-            exit_matcher: &script_with_braces_end,
+            exit_matcher: &exit_with_depth,
         }));
 
     let (remaining, (children, _exit_contents)) = many_till(
@@ -175,49 +169,30 @@ fn script_with_braces<'r, 's>(
     Ok((remaining, children))
 }
 
-#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn script_with_braces_end<'r, 's>(
-    context: Context<'r, 's>,
-    input: OrgSource<'s>,
-) -> Res<OrgSource<'s>, OrgSource<'s>> {
-    let context_depth = get_bracket_depth(context)
-        .expect("This function should only be called from inside a subscript or superscript.");
-    let text_since_context_entry = get_consumed(context_depth.position, input);
-    let mut current_depth = context_depth.depth;
-    for c in Into::<&str>::into(text_since_context_entry).chars() {
-        match c {
-            '{' => {
-                current_depth += 1;
-            }
-            '}' if current_depth == 0 => {
-                panic!("Exceeded subscript or superscript brace depth.")
-            }
-            '}' if current_depth > 0 => {
-                current_depth -= 1;
-            }
-            _ => {}
-        }
+fn script_with_braces_end(
+    starting_brace_depth: isize,
+) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
+    move |context: Context, input: OrgSource<'_>| {
+        _script_with_braces_end(context, input, starting_brace_depth)
     }
-    if current_depth == 0 {
-        let close_bracket = tag::<&str, OrgSource<'_>, CustomError<OrgSource<'_>>>("}")(input);
-        if close_bracket.is_ok() {
-            return close_bracket;
-        }
-    }
-    return Err(nom::Err::Error(CustomError::MyError(MyError(
-        "Not a valid end for subscript or superscript.".into(),
-    ))));
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn get_bracket_depth<'r, 's>(
-    context: Context<'r, 's>,
-) -> Option<&'r SubscriptSuperscriptBrace<'s>> {
-    for node in context.iter() {
-        match node.get_data() {
-            ContextElement::SubscriptSuperscriptBrace(depth) => return Some(depth),
-            _ => {}
-        }
+fn _script_with_braces_end<'r, 's>(
+    _context: Context<'r, 's>,
+    input: OrgSource<'s>,
+    starting_brace_depth: isize,
+) -> Res<OrgSource<'s>, OrgSource<'s>> {
+    let current_depth = input.get_brace_depth() - starting_brace_depth;
+    if current_depth > 0 {
+        // Its impossible for the next character to end the subscript or superscript if we're any amount of braces deep
+        return Err(nom::Err::Error(CustomError::MyError(MyError(
+            "Not a valid end for subscript or superscript.".into(),
+        ))));
     }
-    None
+    if current_depth < 0 {
+        // This shouldn't be possible because if depth is 0 then a closing brace should end the subscript or superscript.
+        unreachable!("Exceeded subscript or superscript brace depth.")
+    }
+    tag("}")(input)
 }