From a628bfac396eb5b24e3326747fd25d5fa7eaba1c Mon Sep 17 00:00:00 2001
From: Celestino Amoroso <celestino.amoroso@gmail.com>
Date: Sun, 21 Apr 2024 07:10:19 +0200
Subject: [PATCH] New symbol '^' (caret). The scanner now returns an error
 token if can't recognise a symbol.

---
 scanner.go | 8 +++++++-
 symbol.go  | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/scanner.go b/scanner.go
index b5e1f18..7acdcb4 100644
--- a/scanner.go
+++ b/scanner.go
@@ -86,13 +86,14 @@ func (self *scanner) Next() (tk *Token) {
 }
 
 func (self *scanner) fetchNextToken() (tk *Token) {
+	var ch byte
 	if err := self.skipBlanks(); err != nil {
 		return self.makeErrorToken(err)
 	}
 
 	escape := false
 	for {
-		ch, _ := self.readChar()
+		ch, _ = self.readChar()
 		switch ch {
 		case '+':
 			if next, _ := self.peek(); next == '+' {
@@ -143,6 +144,8 @@ func (self *scanner) fetchNextToken() (tk *Token) {
 			}
 		case ',':
 			tk = self.makeToken(SymComma, ch)
+		case '^':
+			tk = self.makeToken(SymCaret, ch)
 		case ':':
 			if next, _ := self.peek(); next == ':' {
 				tk = self.moveOn(SymDoubleColon, ch, next)
@@ -271,6 +274,9 @@ func (self *scanner) fetchNextToken() (tk *Token) {
 			break
 		}
 	}
+	if tk == nil {
+		tk = NewErrorToken(self.row, self.column, fmt.Errorf("unknown symbol '%c'", ch))
+	}
 	return
 }
 
diff --git a/symbol.go b/symbol.go
index 9f9f152..0855977 100644
--- a/symbol.go
+++ b/symbol.go
@@ -61,6 +61,7 @@ const (
 	SymDoubleColon                       //  50: '::'
 	SymInsert                            //  51: '>>'
 	SymAppend                            //  52: '<<'
+	SymCaret                             //  53: '^'
 	SymChangeSign
 	SymUnchangeSign
 	SymIdentifier