Ocaml - Files and parsing

Question

How to read contents from file in ocaml? Specifically how to parse them?

Example :

Suppose file contains (a,b,c);(b,c,d)| (a,b,c,d);(b,c,d,e)|

then after reading this, I want two lists containing l1 = [(a,b,c);(b,c,d)] and l2 = [(a,b,c,d);(b,c,d,e)]

Is there any good tutorial for parsing?

Please do not repost questions. If you have anything new to add to your existing question, please edit it instead. — BoltClock, Dec 16 '11 at 17:44

Basile Starynkevitch · Answer 1 · 2011-12-15T08:53:22.190

5

This is a good use case for the menhir parser generator (successor to ocamlyacc). You might want to use ocamllex for lexing. All have good documentation.

You could also use camlp4 or camlp5 stream parsing abilities.

Read also the wikipedia pages on lexing & parsing.

edited Dec 15 '11 at 08:53

answered Dec 15 '11 at 07:12

Basile Starynkevitch

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score 3 · Answer 2 · answered Dec 15 '11 at 23:53

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I'd be inclined to use Aurochs, a PEG parser for something like this. There is example code in the repo there.

answered Dec 15 '11 at 23:53

aneccodeal

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score 2 · Accepted Answer · answered Dec 16 '11 at 15:44

If you want to specify a grammar and have ocaml generate lexers and parsers for you, check out these ocamllex and ocamlyacc tutorials. I recommend doing it this way. If you really only have one type of token in your file format, then ocamlyacc might be overkill if you can just use the lexer to split the file up into tokens that are considered valid by the grammar.

Ocaml - Files and parsing

3 Answers3