Don't Panic! Better, Fewer, Syntax Errors for LR Parsers · HackerPapers discussions

Don't Panic! Better, Fewer, Syntax Errors for LR Parsers — mentioned by bollu

Wed, 15 Jul 2020 20:30:19 GMT

Awesome. I love good research into parsing, since parsing is famously "the solved problem that isn't": https://tratt.net/laurie/blog/entries/parsing_the_solved_pro... I hope to study this paper well (which is by the author of the above post) and understand what their algorithm is. I feel that good error messages make or break a language. Here is the arxiv link of the same paper: https://arxiv.org/pdf/1804.07133.pdf

Paper and discussion history. A mention is not an endorsement.

Don't Panic! Better, Fewer, Syntax Errors for LR Parsers — mentioned by ltratt

Sat, 14 Dec 2019 10:59:21 GMT

I completely agree: the poor quality of error reporting in parsing tools is a significant reason not to use them. When I started looking into this a couple of years back, what surprised me is how much work there's been in this spread over decades. Building upon that (and obvious bias alert!) led us to come up with a couple of new algorithms. The current paper draft is https://arxiv.org/abs/1804.07133 (a future version of that paper will probably chop out MF which, in retrospect, adds too much complexity over CPCT+ for the relatively small gains). The Rust library…

Paper and discussion history. A mention is not an endorsement.

Don't Panic! Better, Fewer, Syntax Errors for LR Parsers — mentioned by ltratt

Fri, 08 Mar 2019 08:34:23 GMT

> They correctly point out that error handling is by far the biggest one, and usually ends up being the biggest part of a parser for a language, full of crufts and strange mixtures of semantics and syntax. Add to this that you frequently want to try to partially recover -- make a guess as to what was intended and continue parsing in the hopes of finding more actionable errors later in the code. I agree. Personally, I ignored automated error handling in parsing for years because it seemed to be a lost cause. Eventually, I decided to look in more detail at it, and soon came across a rich vein…

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Don't Panic! Better, Fewer, Syntax Errors for LR Parsers — mentioned by ltratt

Thu, 08 Nov 2018 11:51:30 GMT

> The problem with yacc/bison-style LALR parser generators is that you end up with an LALR parser. Which works great on syntactically correct code, but trying to get a reasonable error message out of one is about as much fun as repeatedly poking yourself in the eye with a sharp stick. The standard ways of getting error messages from LR parsers are pretty bad, but there is a long line of work that's tried to make it better. If you'll forgive the immodesty on my part, I've been working on updating and fixing that work. There's a draft paper at https://arxiv.org/abs/1804.07133 and a beta-ish…

Paper and discussion history. A mention is not an endorsement.