From 4c09c390fa04e01efc68ed966c127cc5b466728d Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 15 Dec 2022 21:57:21 -0500
Subject: [PATCH] Prevent bold inside bold.

---
 src/parser/nom_context.rs         |  2 ++
 src/parser/text_element_parser.rs | 27 ++++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/parser/nom_context.rs b/src/parser/nom_context.rs
index 98220791..add8ad95 100644
--- a/src/parser/nom_context.rs
+++ b/src/parser/nom_context.rs
@@ -75,6 +75,7 @@ impl<'r, 's> ContextTree<'r, 's> {
                 }
                 ContextElement::PreviousElementNode(_) => {}
                 ContextElement::StartOfParagraph => {}
+                ContextElement::Context(_) => {}
             };
         }
         // TODO: Make this a custom error
@@ -87,6 +88,7 @@ impl<'r, 's> ContextTree<'r, 's> {
 pub enum ContextElement<'r, 's> {
     ExitMatcherNode(ExitMatcherNode<'r>),
     PreviousElementNode(PreviousElementNode<'s>),
+    Context(&'r str),
     StartOfParagraph,
 }
 
diff --git a/src/parser/text_element_parser.rs b/src/parser/text_element_parser.rs
index 569e3474..876ef3ef 100644
--- a/src/parser/text_element_parser.rs
+++ b/src/parser/text_element_parser.rs
@@ -53,6 +53,7 @@ where
     O: Into<Token<'s>>,
 {
     move |mut i: I| {
+        // TODO: Can I eliminate the clone?
         let mut current_context = context.clone();
         // Despite the clone, the Rc should still point to the same value, otherwise we'll get stuck in an endless loop.
         assert!(current_context.ptr_eq(context));
@@ -68,6 +69,7 @@ where
                         match context_element {
                             ContextElement::ExitMatcherNode(_) => {}
                             ContextElement::StartOfParagraph => {}
+                            ContextElement::Context(_) => {}
                             ContextElement::PreviousElementNode(PreviousElementNode {
                                 element: token,
                             }) => {
@@ -123,6 +125,23 @@ pub fn context_paragraph_end<'s, 'r>(
 }
 
 fn can_start_bold<'s, 'r>(context: Context<'r, 's>) -> bool {
+    _preceded_by_whitespace(context) && !_in_section(context, "bold")
+}
+
+fn _in_section<'s, 'r, 'x>(context: Context<'r, 's>, section_name: &'x str) -> bool {
+    for thing in context.iter() {
+        match thing.get_data() {
+            ContextElement::ExitMatcherNode(_) => {}
+            ContextElement::PreviousElementNode(_) => {}
+            ContextElement::Context(name) if *name == section_name => return true,
+            ContextElement::Context(_) => {}
+            ContextElement::StartOfParagraph => {} // TODO: If we specialize this to bold then this would be a good spot to stop scanning
+        }
+    }
+    false
+}
+
+fn _preceded_by_whitespace<'s, 'r>(context: Context<'r, 's>) -> bool {
     let mut context_iterator = context.iter().enumerate();
     loop {
         if let Some((i, ctx)) = context_iterator.next() {
@@ -145,6 +164,7 @@ fn can_start_bold<'s, 'r>(context: Context<'r, 's>) -> bool {
                 ContextElement::StartOfParagraph => {
                     return true;
                 }
+                ContextElement::Context(_) => {}
             }
         } else {
             break;
@@ -224,10 +244,11 @@ fn flat_text_element<'s, 'r>(
 
 fn flat_bold<'s, 'r>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str, Bold<'s>> {
     let bold_start = parser_with_context!(context_bold_start)(&context);
-    let nom_context =
-        context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
+    let nom_context = context
+        .with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
             exit_matcher: ChainBehavior::AndParent(Some(&context_bold_end)),
-        }));
+        }))
+        .with_additional_node(ContextElement::Context("bold"));
     let (remaining, captured) = recognize(tuple((bold_start, |i| {
         context_many_till(&nom_context, flat_text_element, context_bold_end)(i)
     })))(i)?;