Fix the memory problem

parse.go

@@ -12,7 +12,7 @@ func parseString (text string) ([]runeLayout, []token) {
 
 	var index         int
 	var startingIndex int
-	var run           rune
+	var runl          runeLayout
 	var lastRune      rune
 
 	var tok token
@@ -31,19 +31,26 @@ func parseString (text string) ([]runeLayout, []token) {
 		}
 	}
 
-	for index, run = range text {
+	// build the rune slice
+	// we need to do this before parsing into tokens, because otherwise
+	// a realloc will occur in the middle of it and the tokens at the start
+	// will be referencing old memory
+	for _, run := range text {
 		runes = append(runes, runeLayout {
 			run: run,
 		})
+	}
 
+	// parse tokens
+	for index, runl = range runes {
 		switch {
-		case run == '\r':
+		case runl.run == '\r':
 			tokenBoundary()
 			// we don't know the token type yet. if next rune is a
 			// \n then this is a CRLF line break. if not, this is
 			// just a word.
 			
-		case run == '\n':
+		case runl.run == '\n':
 			if lastRune == '\r' {
 				// continue the \r to make a CRLF line break
 				tok.kind = tokenKindLineBreak
@@ -52,16 +59,16 @@ func parseString (text string) ([]runeLayout, []token) {
 				tok.kind = tokenKindLineBreak
 			}
 
-		case run == '\t':
+		case runl.run == '\t':
 			mustBeInToken(tokenKindTab)
 
-		case unicode.IsSpace(run):
+		case unicode.IsSpace(runl.run):
 			mustBeInToken(tokenKindSpace)
 
 		default:
 			mustBeInToken(tokenKindWord)
 		}
-		lastRune = run
+		lastRune = runl.run
 	}
 	index ++ // make index equal to len([]rune(text))