Started on the parser. Thinking about some tweaks.

 - Creating a LookaheadIterator as a general class that could be used.
 - Wrap symbols in a symbol struct that tracks symbol start and end
   position for error reporting.
 - Make a struct for position in a file as well.

1 files changed, 10 insertions, 4 deletions

diff --git a/src/lexer.rs b/src/lexer.rs
index e80e461..94825b2 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -2,7 +2,12 @@ use std::iter::Iterator;
 //use core::error::Error;
 use std::str::CharIndices;
 
-#[derive(Debug)]
+#[derive(Debug,Copy,Clone)]
+pub enum ErrorType {
+    UnexpectedChar(char),
+}
+
+#[derive(Debug,Copy,Clone)]
 pub enum Symbol<'a> {
     StartFlat,
     StartPoint,
@@ -15,7 +20,7 @@ pub enum Symbol<'a> {
     Token(&'a str),
     Literal(&'a str),
     Text(&'a str),
-    Error{ line: u32, row: u32, what: String },
+    Error{ line: u32, row: u32, what: ErrorType },
     EOS,
 }
 
@@ -104,7 +109,7 @@ impl<'a> Lexer<'a> {
         }
     }
 
-    fn error( &self, what: String ) -> Option<Symbol<'a>> {
+    fn error( &self, what: ErrorType ) -> Option<Symbol<'a>> {
         Some(Symbol::Error {
             line: self.line,
             row: self.row,
@@ -162,6 +167,7 @@ impl<'a> Lexer<'a> {
                 return self.parse_literal_str();
             }
             Some('=') => {
+                self.next();
                 return Some(Symbol::Equals);
             }
             _ => {}
@@ -186,7 +192,7 @@ impl<'a> Lexer<'a> {
 
     fn parse_literal_str(&mut self) -> Option<Symbol<'a>> {
         if let Some(chr) = self.cur() && chr != '"' {
-            return self.error(format!("Expected '\"' but found '{}'", chr));
+            return self.error( ErrorType::UnexpectedChar(chr) );
         }
         let start = self.peek_index();
         while self.next().is_some_and(|chr| chr != '"') { }