Add forms 4 and 5 of LaTeX fragment.

src/parser/latex_fragment.rs

@@ -3,19 +3,24 @@ use nom::bytes::complete::tag;
 use nom::character::complete::alpha1;
 use nom::character::complete::anychar;
 use nom::character::complete::line_ending;
+use nom::character::complete::none_of;
 use nom::character::complete::one_of;
 use nom::character::complete::space0;
 use nom::combinator::opt;
 use nom::combinator::peek;
 use nom::combinator::recognize;
+use nom::combinator::verify;
 use nom::multi::many_till;
 use nom::sequence::tuple;
 
 use super::Context;
+use crate::error::CustomError;
+use crate::error::MyError;
 use crate::error::Res;
 use crate::parser::parser_with_context::parser_with_context;
 use crate::parser::util::exit_matcher_parser;
 use crate::parser::util::get_consumed;
+use crate::parser::util::get_one_before;
 use crate::parser::LatexFragment;
 
 #[tracing::instrument(ret, level = "debug")]
@@ -27,6 +32,8 @@ pub fn latex_fragment<'r, 's>(
         parser_with_context!(raw_latex_fragment)(context),
         parser_with_context!(escaped_parenthesis_fragment)(context),
         parser_with_context!(escaped_bracket_fragment)(context),
+        parser_with_context!(double_dollar_fragment)(context),
+        parser_with_context!(dollar_char_fragment)(context),
     ))(input)?;
     let (remaining, _) = space0(remaining)?;
     let source = get_consumed(input, remaining);
@@ -114,3 +121,58 @@ fn escaped_bracket_fragment<'r, 's>(
     let source = get_consumed(input, remaining);
     Ok((remaining, source))
 }
+
+#[tracing::instrument(ret, level = "debug")]
+fn double_dollar_fragment<'r, 's>(
+    context: Context<'r, 's>,
+    input: &'s str,
+) -> Res<&'s str, &'s str> {
+    // TODO: The documentation on the dollar sign versions is incomplete. Test to figure out what the real requirements are. For example, can this span more than 3 lines and can this contain a single $ since its terminated by $$?
+    let (remaining, _) = tag("$$")(input)?;
+    let (remaining, _) = recognize(many_till(
+        anychar,
+        peek(alt((
+            parser_with_context!(exit_matcher_parser)(context),
+            tag("$"),
+        ))),
+    ))(remaining)?;
+    let (remaining, _) = tag("$$")(remaining)?;
+
+    let source = get_consumed(input, remaining);
+    Ok((remaining, source))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+fn dollar_char_fragment<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+    let (_, _) = pre(context, input)?;
+    let (remaining, _) = tag("$")(input)?;
+    let (remaining, _) = verify(none_of(".,?;\""), |c| !c.is_whitespace())(remaining)?;
+    let (remaining, _) = tag("$")(remaining)?;
+    let (_, _) = peek(parser_with_context!(post)(context))(remaining)?;
+
+    let source = get_consumed(input, remaining);
+    Ok((remaining, source))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+pub fn pre<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
+    let document_root = context.get_document_root().unwrap();
+    let preceding_character = get_one_before(document_root, input)
+        .map(|slice| slice.chars().next())
+        .flatten();
+    if let Some('$') = preceding_character {
+        return Err(nom::Err::Error(CustomError::MyError(MyError(
+            "Not a valid pre character for dollar char fragment.",
+        ))));
+    }
+    Ok((input, ()))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+pub fn post<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
+    // TODO: What about eof? Test to find out.
+
+    // TODO: Figure out which punctuation characters should be included.
+    let (remaining, _) = alt((recognize(one_of(" \t-.,;:!?'\"")), line_ending))(input)?;
+    Ok((remaining, ()))
+}