update all index() uses

tools/vrepl.v

@@ -187,7 +187,11 @@ fn print_output(s os.Result) {
 	for line in lines {
 		if line.starts_with('.vrepl_temp.v') {
 			// Hide the temporary file name
-			println(line[line.index(' ') + 1 .. ])
+			idx := line.index(' ') or {
+				println(line)
+				return
+			}
+			println(line[idx+1..])
 		}	 else {
 			println(line)
 		}

vlib/compiler/tests/msvc_test.v

@@ -21,8 +21,10 @@ fn test_flag_parsing() {
 
 		// Which ever one of these is lowest we use
 		// TODO: we really shouldnt support all of these cmon
-		mut lowest := base.index('-')
-		for x in [base.index(' '), base.index(',')] {
+		mut lowest := base.index('-') or { -1 }
+		a := base.index(' ') or { -1 }
+		b := base.index(',') or { -1 }
+		for x in [a, b] {
 			if (x < lowest && x != -1) || lowest == -1 {
 				lowest = x
 			}

vlib/encoding/csv/reader.v

@@ -113,8 +113,7 @@ fn (r mut Reader) read_record() ?[]string {
 	for {
 		// not quoted
 		if line[0] != `"` {
-			i = line.index(r.delimiter.str())
-			if i == -1 {
+			i = line.index(r.delimiter.str()) or {
 				// last
 				break
 			}
@@ -125,8 +124,7 @@ fn (r mut Reader) read_record() ?[]string {
 		// quoted
 		else {
 			line = line[1..]
-			i = line.index('"')
-			if i != -1 {
+			if i := line.index('"') {
 				if i+1 == line.len {
 					// last record
 					fields << line[..i]
@@ -145,7 +143,6 @@ fn (r mut Reader) read_record() ?[]string {
 			return err_invalid_delim
 		}
 	}
-	
 	return fields
 }
 

vlib/http/http.v

@@ -185,15 +185,14 @@ fn parse_response(resp string) Response {
 			break
 		}
 		i++
-		pos := h.index(':')
-		if pos == -1 {
+		pos := h.index(':') or {
 			continue
 		}
 		//if h.contains('Content-Type') {
 			//continue
 		//}
 		key := h[..pos]
-		val := h[pos + 2..]
+		val := h[pos+2..]
 		headers[key] = val.trim_space()
 	}