Fixed some lexer/parser bugs related to lexer errors.

dm/src/repl.rs

@@ -105,12 +105,14 @@ fn compile_statement(
     register_count: usize,
     constants_table: &mut ConstantsTable,
 ) -> Result<Function, Diagnostics> {
-    let (maybe_statement, parse_diagnostics) = parse_statement(input);
-    if !parse_diagnostics.is_empty() {
-        Err(parse_diagnostics)
-    } else if let Some(statement) = maybe_statement {
-        session.compile_statement(&statement, register_count, constants_table)
+    let maybe_statement = parse_statement(input);
+    if !maybe_statement.is_ok() {
+        Err(maybe_statement.into_diagnostics())
     } else {
-        panic!("Unable to unwrap statement from previous input.")
+        session.compile_statement(
+            &maybe_statement.into_inner(),
+            register_count,
+            constants_table,
+        )
     }
 }

dmc-lib/src/lexer.rs

@@ -118,11 +118,10 @@ impl<'a> Lexer<'a> {
                         }
                     }
                     if !terminated {
-                        return Some(Err(LexerError::new(
-                            self.position,
-                            end,
-                            LexerErrorKind::UnterminatedString,
-                        )));
+                        let err =
+                            LexerError::new(self.position, end, LexerErrorKind::UnterminatedString);
+                        self.position = end;
+                        return Some(Err(err));
                     }
                     (end, TokenKind::String)
                 } else {
@@ -137,11 +136,13 @@ impl<'a> Lexer<'a> {
                     }
 
                     if prefix.len() == 0 {
-                        return Some(Err(LexerError::new(
+                        let err = LexerError::new(
                             self.position,
                             self.position + 1,
                             LexerErrorKind::UnrecognizedCharacter(chunk.chars().next().unwrap()),
-                        )));
+                        );
+                        self.position += 1;
+                        return Some(Err(err));
                     }
 
                     let token_kind = match prefix.as_str() {