try a method for matching delimiters (#36)

How does this look? Is this correct? Should I peek and store that in a
variable for performance? Or readability?

---------

Co-authored-by: Keith Cirkel <[email protected]>

crates/hdx_parser/src/comparison.rs

@@ -1,5 +1,6 @@
+use crate::match_delim;
 use crate::{unexpected, Parse, Parser, Result};
-use hdx_lexer::{Include, Token};
+use hdx_lexer::Include;
 
 #[derive(Debug, PartialEq, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize), serde(tag = "type"))]
@@ -13,25 +14,27 @@ pub enum Comparison {
 
 impl<'a> Parse<'a> for Comparison {
 	fn parse(parser: &mut Parser<'a>) -> Result<Comparison> {
-		Ok(match parser.next() {
-			Token::Delim('=') => Comparison::Equal,
-			Token::Delim('>') => {
-				if let Token::Delim('=') = parser.peek_with(Include::Whitespace) {
-					parser.advance_with(Include::Whitespace);
-					Comparison::GreaterThanEqual
-				} else {
-					Comparison::GreaterThan
+		Ok(match_delim! {parser.next() :
+		  '=' => Comparison::Equal,
+		  '>' => {
+				match_delim!{ parser.peek_with(Include::Whitespace) :
+					'=' => {
+					   parser.advance_with(Include::Whitespace);
+					   Comparison::GreaterThanEqual
+					},
+					_ =>  Comparison::GreaterThan
 				}
-			}
-			Token::Delim('<') => {
-				if let Token::Delim('=') = parser.peek_with(Include::Whitespace) {
-					parser.advance_with(Include::Whitespace);
-					Comparison::LessThanEqual
-				} else {
-					Comparison::LessThan
+			},
+			'<' => {
+				match_delim!{ parser.peek_with(Include::Whitespace) :
+					'=' => {
+								parser.advance_with(Include::Whitespace);
+								Comparison::LessThanEqual
+					},
+					_ => Comparison::LessThan
 				}
-			}
-			token => unexpected!(parser, token),
+			},
+			token =>  unexpected!(parser, token)
 		})
 	}
 }

crates/hdx_parser/src/macros.rs

@@ -282,3 +282,17 @@ macro_rules! match_ignore_case {
 		}
 	};
 }
+
+#[macro_export]
+macro_rules! match_delim {
+       ( $parser: ident.$method: ident($($args: tt)*):
+           $(
+              $pattern:pat $(if $guard:expr)?  => $then: expr
+           ),+
+           $(,)?
+       ) => {
+		match $parser.$method($($args)*).char() {
+		    $(Some($pattern) $( if $guard )? => $then,)+
+		}
+	};
+}