Wiring up the parser with the runtime.

 - small bug fixes in scanner and parser logic

ast_printer.go

@@ -7,19 +7,8 @@ import (
 
 type AstPrinter struct{}
 
-func (ap *AstPrinter) Print() string {
-	exp := &Binary{
-		Left: &Unary{
-			Operator: NewToken(Minus, "-", nil, 1),
-			Right:    &Literal{Value: 123},
-		},
-		Operator: NewToken(Star, "*", nil, 1),
-		Right: &Grouping{
-			Expression: &Literal{Value: 45.67},
-		},
-	}
-
-	return exp.Accept(ap).(string)
+func (ap *AstPrinter) Print(expr Expr) string {
+	return expr.Accept(ap).(string)
 }
 
 func (ap *AstPrinter) VisitBinaryExpr(expr *Binary) interface{} {

glox.go

@@ -66,7 +66,17 @@ func (r *Runtime) Error(line int, message string) {
 
 func (r *Runtime) run(source string) {
 	scanner := NewScanner(bytes.NewBuffer([]byte(source)), r)
-	_ = scanner.ScanTokens()
+	tokens := scanner.ScanTokens()
+
+	parser := NewParser(tokens, r)
+	expr := parser.Parse()
+
+	printer := &AstPrinter{}
+	if r.hadError {
+		return
+	}
+
+	fmt.Println(printer.Print(expr))
 
 	// for _, token := range tokens {
 	// 	if token.Type == String {

parser.go

@@ -245,7 +245,7 @@ func (p *Parser) consume(tokenType TokenType, message string) (Token, error) {
 		return p.advance(), nil
 	}
 
-	return Token{}, NewParseError(message)
+	return Token{}, p.error(p.peek(), message)
 }
 
 // isAtEnd checks if we have run out of tokens to parse.

scanner.go

@@ -93,7 +93,7 @@ func (sc *Scanner) scanToken() {
 		if sc.match('=') {
 			sc.addToken(BangEqual, nil)
 		} else {
-			sc.addToken(Equal, nil)
+			sc.addToken(Bang, nil)
 		}
 	case '=':
 		if sc.match('=') {