From 1da38c8f7d42905e4ac4e7af91b898afd3acf1b2 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Fri, 16 Dec 2022 01:35:49 -0500
Subject: [PATCH] Use context_many1 for paragraphs in a document.

---
 src/parser/combinator.rs          |  3 ++-
 src/parser/text.rs                |  6 ++++++
 src/parser/text_element_parser.rs | 32 +++++++++++++++++++++----------
 src/parser/token.rs               |  8 ++++++++
 4 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/src/parser/combinator.rs b/src/parser/combinator.rs
index 58ea89b..f5d5fca 100644
--- a/src/parser/combinator.rs
+++ b/src/parser/combinator.rs
@@ -72,7 +72,7 @@ where
                 }
             }
         }
-        let elements: Vec<Token<'s>> = current_context
+        let mut elements: Vec<Token<'s>> = current_context
             .into_iter_until(context)
             .filter_map(|context_element| match context_element {
                 ContextElement::PreviousElementNode(elem) => Some(elem.element),
@@ -86,6 +86,7 @@ where
                 err?;
             }
         }
+        elements.reverse();
         Ok((i, elements))
     }
 }
diff --git a/src/parser/text.rs b/src/parser/text.rs
index 69da8ac..fa98650 100644
--- a/src/parser/text.rs
+++ b/src/parser/text.rs
@@ -79,6 +79,12 @@ pub struct Link<'a> {
     pub contents: &'a str,
 }
 
+#[derive(Debug)]
+pub struct Paragraph<'a> {
+    pub contents: Vec<TextElement<'a>>,
+    pub paragraph_end: &'a str,
+}
+
 pub fn line_break(input: &str) -> Res<&str, LineBreak> {
     map(line_ending, |s: &str| LineBreak { contents: s })(input)
 }
diff --git a/src/parser/text_element_parser.rs b/src/parser/text_element_parser.rs
index b60f27f..a065e03 100644
--- a/src/parser/text_element_parser.rs
+++ b/src/parser/text_element_parser.rs
@@ -21,6 +21,7 @@ use super::text::span;
 use super::text::symbol;
 use super::text::Bold;
 use super::text::Link;
+use super::text::Paragraph;
 use super::text::Res;
 use super::text::TextElement;
 use super::token::Token;
@@ -45,10 +46,16 @@ use nom::InputLength;
 
 type UnboundMatcher<'r, 's, I, O, E> = dyn Fn(Context<'r, 's>, I) -> IResult<I, O, E>;
 
-pub fn document(input: &str) -> Res<&str, Vec<(Vec<TextElement>, &str)>> {
+pub fn document(input: &str) -> Res<&str, Vec<Paragraph>> {
     let initial_context: ContextTree<'_, '_> = ContextTree::new();
-    let ret = context_many1(&initial_context, paragraph)(input);
-    ret
+    let (remaining, tokens) = context_many1(&initial_context, paragraph)(input)?;
+    let paragraphs = tokens.into_iter().map(|token| {
+        match token {
+            Token::TextElement(_) => unreachable!(),
+            Token::Paragraph(paragraph) => paragraph,
+        }
+    }).collect();
+    Ok((remaining, paragraphs))
 }
 
 pub fn context_paragraph_end<'s, 'r>(
@@ -93,6 +100,7 @@ fn _preceded_by_whitespace<'s, 'r>(context: Context<'r, 's>) -> bool {
                                 TextElement::Link(_) => return false,
                             };
                         }
+                        Token::Paragraph(_) => unreachable!(),
                     };
                 }
                 ContextElement::StartOfParagraph => {
@@ -134,26 +142,30 @@ pub fn context_bold_end<'s, 'r>(context: Context<'r, 's>, input: &'s str) -> Res
     Ok((remaining, actual_match))
 }
 
-pub fn paragraph<'s, 'r>(
-    context: Context<'r, 's>,
-    i: &'s str,
-) -> Res<&'s str, (Vec<TextElement<'s>>, &'s str)> {
+pub fn paragraph<'s, 'r>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str, Paragraph<'s>> {
     // Add a not(eof) check because many_till cannot match a zero-length string
     not(eof)(i)?;
     let paragraph_context = context
-        .with_additional_node(ContextElement::StartOfParagraph)
         .with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
             exit_matcher: ChainBehavior::AndParent(Some(&context_paragraph_end)),
-        }));
+        }))
+        .with_additional_node(ContextElement::StartOfParagraph);
     let (remaining, (many, till)) =
         context_many_till(&paragraph_context, flat_text_element, context_paragraph_end)(i)?;
     let many = many
         .into_iter()
         .filter_map(|token| match token {
             Token::TextElement(text_element) => Some(text_element),
+            Token::Paragraph(_) => panic!("There should only be text elements in paragraphs."),
         })
         .collect();
-    Ok((remaining, (many, till)))
+    Ok((
+        remaining,
+        Paragraph {
+            contents: many,
+            paragraph_end: till,
+        },
+    ))
 }
 
 fn flat_text_element<'s, 'r>(
diff --git a/src/parser/token.rs b/src/parser/token.rs
index 64eb783..959e633 100644
--- a/src/parser/token.rs
+++ b/src/parser/token.rs
@@ -1,8 +1,10 @@
+use super::text::Paragraph;
 use super::text::TextElement;
 
 #[derive(Debug)]
 pub enum Token<'a> {
     TextElement(TextElement<'a>),
+    Paragraph(Paragraph<'a>),
 }
 
 impl<'a> Into<Token<'a>> for TextElement<'a> {
@@ -10,3 +12,9 @@ impl<'a> Into<Token<'a>> for TextElement<'a> {
         Token::TextElement(self)
     }
 }
+
+impl<'a> Into<Token<'a>> for Paragraph<'a> {
+    fn into(self) -> Token<'a> {
+        Token::Paragraph(self)
+    }
+}