From 36210c2d7f9e5a23f392aaf6a3a98fe6b81ace0d Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 23 Mar 2023 16:40:39 -0400
Subject: [PATCH] Add a DocumentRoot context element storing the original full
 document.

This might be used for look-behind instead of storing previous element nodes in the context tree.
---
 src/parser/bold.rs           |  3 +++
 src/parser/combinator.rs     | 10 ++--------
 src/parser/document.rs       |  5 ++++-
 src/parser/parser_context.rs |  1 +
 src/parser/util.rs           | 19 ++++++++++++++-----
 5 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/src/parser/bold.rs b/src/parser/bold.rs
index a8dc00a..004e7f0 100644
--- a/src/parser/bold.rs
+++ b/src/parser/bold.rs
@@ -96,6 +96,9 @@ fn _preceded_by_whitespace<'r, 's>(context: Context<'r, 's>) -> bool {
                 }
                 ContextElement::Context(_) => {}
                 ContextElement::ListItem(_) => {}
+                ContextElement::DocumentRoot(_) => {
+                    return true;
+                }
             }
         } else {
             break;
diff --git a/src/parser/combinator.rs b/src/parser/combinator.rs
index 4b99f84..5cb3102 100644
--- a/src/parser/combinator.rs
+++ b/src/parser/combinator.rs
@@ -43,10 +43,7 @@ where
             .into_iter_until(context)
             .filter_map(|context_element| match context_element {
                 ContextElement::PreviousElementNode(elem) => Some(elem.element),
-                ContextElement::ExitMatcherNode(_) => None,
-                ContextElement::Context(_) => None,
-                ContextElement::StartOfParagraph => None,
-                ContextElement::ListItem(_) => None,
+                _ => None,
             })
             .collect();
         if elements.is_empty() {
@@ -86,15 +83,12 @@ where
                         let context_element = context_element.expect("We only pop off context elements created in this function, so they are all Some()");
                         current_context = next_context;
                         match context_element {
-                            ContextElement::ExitMatcherNode(_) => {}
-                            ContextElement::StartOfParagraph => {}
-                            ContextElement::Context(_) => {}
                             ContextElement::PreviousElementNode(PreviousElementNode {
                                 element: token,
                             }) => {
                                 ret.push(token);
                             }
-                            ContextElement::ListItem(_) => {}
+                            _ => {}
                         };
                     }
                     ret.reverse();
diff --git a/src/parser/document.rs b/src/parser/document.rs
index d9571a8..1c8dd04 100644
--- a/src/parser/document.rs
+++ b/src/parser/document.rs
@@ -2,6 +2,7 @@
 use super::combinator::context_many1;
 use super::error::Res;
 use super::paragraph::paragraph;
+use super::parser_context::ContextElement;
 use super::parser_context::ContextTree;
 use super::token::Paragraph;
 use super::token::Token;
@@ -14,7 +15,9 @@ type UnboundMatcher<'r, 's, I, O, E> = dyn Fn(Context<'r, 's>, I) -> IResult<I,
 
 pub fn document(input: &str) -> Res<&str, Vec<Paragraph>> {
     let initial_context: ContextTree<'_, '_> = ContextTree::new();
-    let (remaining, tokens) = context_many1(&initial_context, paragraph)(input)?;
+    let document_context =
+        initial_context.with_additional_node(ContextElement::DocumentRoot(input));
+    let (remaining, tokens) = context_many1(&document_context, paragraph)(input)?;
     let paragraphs = tokens
         .into_iter()
         .map(|token| match token {
diff --git a/src/parser/parser_context.rs b/src/parser/parser_context.rs
index 44fc9e1..1ffe709 100644
--- a/src/parser/parser_context.rs
+++ b/src/parser/parser_context.rs
@@ -94,6 +94,7 @@ impl<'r, 's> ContextTree<'r, 's> {
 
 #[derive(Debug)]
 pub enum ContextElement<'r, 's> {
+    DocumentRoot(&'s str),
     ExitMatcherNode(ExitMatcherNode<'r>),
     PreviousElementNode(PreviousElementNode<'s>),
     Context(&'r str),
diff --git a/src/parser/util.rs b/src/parser/util.rs
index 3600c13..7cee250 100644
--- a/src/parser/util.rs
+++ b/src/parser/util.rs
@@ -1,15 +1,24 @@
 use super::parser_context::ContextElement;
 use super::Context;
 
+/// Check if we are below a section of the given section type regardless of depth
 pub fn in_section<'r, 's, '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
-            ContextElement::ListItem(_) => {}
+            _ => {}
+        }
+    }
+    false
+}
+
+/// Checks if we are currently an immediate child of the given section type
+pub fn immediate_in_section<'r, 's, 'x>(context: Context<'r, 's>, section_name: &'x str) -> bool {
+    for thing in context.iter() {
+        match thing.get_data() {
+            ContextElement::Context(name) if *name == section_name => return true,
+            ContextElement::Context(name) if *name != section_name => return false,
+            _ => {}
         }
     }
     false