pandeykartikey / goto Goto Github PK

cat len.goto
print( len( "狐犬" ) );

goto len.goto 
6
null

return &object.Integer{Value: int64(utf8.RuneCountInString(arg.Value))}

return &object.Integer{Value: int64(len(arg.Value))}

$ cat in.go
print( "steve );

diff --git a/lexer/lexer.go b/lexer/lexer.go
index dafc23a..48c7654 100644
--- a/lexer/lexer.go
+++ b/lexer/lexer.go
@@ -47,7 +47,7 @@ func (l *Lexer) skipComments() {
 func (l *Lexer) readSequence(f func(byte) bool) string {
        position := l.position
 
-       for f(l.ch) {
+       for l.ch != 0 && f(l.ch) {
                l.readChar()
        }

$ cat  div.to
print( 1 / 0 );

$ goto div.to
panic: runtime error: integer divide by zero

goroutine 1 [running]:
github.com/pandeykartikey/goto/eval.evalInfixIntegerExpression(0x5f95ef, 0x1, 0xc0000b4048, 0xc0000b4040, 0x0, 0x410d1b)
	/home/skx/go/src/github.com/pandeykartikey/goto/eval/eval.go:113 +0x6fc
github.com/pandeykartikey/goto/eval.evalInfixExpression(0x5f95ef, 0x1, 0x54df20, 0xc0000b4048, 0x54df20, 0xc0000b4040, 0x7f0ab170e100, 0x20300000000000)
..

frodo ~/go/src/github.com/pandeykartikey/goto $ git diff eval/eval.go
diff --git a/eval/eval.go b/eval/eval.go
index c2e3e43..9a05b11 100644
--- a/eval/eval.go
+++ b/eval/eval.go
@@ -110,6 +110,9 @@ func evalInfixIntegerExpression(op string, left *object.Integer, right *object.I
        case "*":
                return &object.Integer{Value: leftVal * rightVal}
        case "/":
+               if rightVal == 0 {
+                       return errorMessageToObject("division by zero")
+               }
                return &object.Integer{Value: leftVal / rightVal}
        case "%":
                return &object.Integer{Value: leftVal % rightVal}