SebastianVerified account

Why do most (at least JS) parsers restrict syntax errors to a single position? eg. only a single column/line, rather than having a range of start/end? The errors would be a lot richer.

I’ve always assumed it was bc once they encountered that error they couldn’t parse the rest of the document and find the end position. Might be a naive take on it though.

This rarely, if ever, happens in practice—a good parser tries as hard as it can to “recover” from input it doesn’t understand. That’s how, in your favorite editor, you can type something totally bananas, then go back to writing valid JS and only the bad part has red squigglies.

I'd say it's the opposite. IDE/editor parsers are the minority. None of the parsers I've ever worked with had to care about parsing invalid input. Why would it need to?