That's simple... to start a string literal, you type a ", and as you type the green box will continue to expand to contain what you're typing until you type another " to end the literal. This is, somehow, better...
Simply render "xxxx" differently and you are about done; e.g. render it as ˹xxxx˼ with some background highlight.
Incremental text input is a different problem. If you only have to deal with a batch renderer, then no change is needed; if you have an interactive IDE, you might want to complete the closing " so feedback remains sane.
Incremental text input is a different problem. If you only have to deal with a batch renderer, then no change is needed; if you have an interactive IDE, you might want to complete the closing " so feedback remains sane.