How can I skip spaces when parsing a haskell string

Question

I have the following definition in a parser using the Haskell ReadP library:

expr = chainl1 comp (string "===" >> return fun6)

How can I skip spaces before the === operator? I don't know how to include it in this syntax.

I think the question is too broad, since it sounds like an answer would need to explain basic syntax, monads, and monadic parsing. There are lots of tutorials that deal with parser combinator libraries you can check out — jberryman, Nov 01 '15 at 20:11
I know how to parse, i am just having some trouble with syntax in this one. Everything is working but when i try to parse strings with spaces before operators, they fail.... — Ezis, Nov 01 '15 at 20:20

score 1 · Accepted Answer · answered Nov 02 '15 at 01:51

1

ReadP has skipSpaces for exactly that usecase; your parser then becomes

expr = chainl1 comp (skipSpaces >> string "===" >> return fun6)

answered Nov 02 '15 at 01:51

Cactus

1 Answers1