Move char matching util function out of tokenize.tossUntilNeitherOf()

In preparation for reuse by next commit.

app/tokenize/tokenize.go

@@ -49,21 +49,13 @@ func (self *reader) takeUntil(needle string) (string, bool) {
 
 func (self *reader) tossUntilNeitherOf(needles string) bool {
 	self.checkPos()
-	match := func(b byte, ns string) bool {
-		for i := range len(ns) {
-			if b == ns[i] {
-				return true
-			}
-		}
-		return false
-	}
 	tossed := uint(0)
 	for {
 		idx := self.pos + tossed
 		if idx == self.len() {
 			break
 		}
-		if match(self.data[idx], needles) {
+		if hasByte(self.data[idx], needles) {
 			tossed += 1
 			continue
 		}
@@ -73,6 +65,15 @@ func (self *reader) tossUntilNeitherOf(needles string) bool {
 	return tossed > 0
 }
 
+func hasByte(b byte, ns string) bool {
+	for i := range len(ns) {
+		if b == ns[i] {
+			return true
+		}
+	}
+	return false
+}
+
 func (self *reader) tossChar() {
 	self.checkPos()
 	self.pos += 1