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Parser Combinators Beat Regexes

(entropicthoughts.com)
120 points mooreds | 2 comments | | HN request time: 0s | source
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yen223 ◴[] No.43639551[source]
Parser combinators are one of those ideas that is really powerful in practice, but will never be mainstream because it had the bad fortune of coming from the functional programming world. It's a shame too, because parser combinators are what made parsers click for me.

Take the hard problem of parsing a language, break it down into the much simpler problem of reading tokens, then write simple "combinators" (and, or, one_or_many, etc etc) to combine these simple parsers into larger more complex parsers.

You could almost build an entire parser combinator library from scratch from memory, because none of the individual components are complicated.

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1. conaclos ◴[] No.43642148[source]
I once tried to use parser combinators and I was quite disappointed by the result. I find it harder to read and to handle error than regular recursive descendant parsers.
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2. fooker ◴[] No.43646849[source]
The trick is to have your grammar or combinator setup to have error productions for all the common errors you can think of.

That way you get nice, targeted error messages.