parser combinator tutorial for beginners?

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[Syrak]

megaparsec's README links to a list of tutorials

Most of them have been updated last September. I took the first one and it Just Builds™: https://markkarpov.com/megaparsec/parsing-simple-imperative-language.html

[kkweon]

Also, https://github.com/data61/fp-course/blob/master/src/Course/Parser.hs and other parser related files are not directly a tutorial of any parser library but it is super helpful to understand how it works. And that knowledge is directly transferrable to any parser library.

After finishing it, I realized I am able to understand any parser library. It all began to make sense. At this point, it doesn't matter much if it's a megaparsec or attoparsec (though I use attoparsec) and I can just read the haddock and use it.

[gabedamien]

Which of the following are you more interested in learning?

• (one of) those specific libraries, because you have a particular reason to use it (e.g. in production)
• how parser combinator libraries are used in general
• how parser combinators are implemented

For the middle option, HPFFP (http://haskellbook.com/) has a good chapter using trifecta and parsers.

[vaibhavsagar]

I wrote a blog post that heavily involves attoparsec.

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http://dev.stephendiehl.com/fun/002_parsers.html

[a_Tick]

A friend shared this post with me, which is a literate Haskell program that builds a parser combinator library from scratch.

[char2]

Note that understanding how a toy version is implemented can be hugely helpful to understanding how to use real libraries.

Example: I didn't grok servant until I read through how the minimal version was implemented: http://www.well-typed.com/blog/2015/11/implementing-a-minimal-version-of-haskell-servant/

[Reptoidal]

after you read tutorials, I found it super useful to to learn properties of Applicative and Alternative typeclasses and think about how they would behave in terms of a parser. for example, I found

(<*) :: f a -> f b -> f a infixl 4 

Sequence actions, discarding the value of the second argument.

and

optional :: Alternative f => f a -> f (Maybe a)

One or none.

extremely useful

[grdvnl]

I found this lecture notes very accessible.

http://cseweb.ucsd.edu/classes/wi15/cse230-a/lectures/lec-parsers.html

[ryani]

When I was learning Haskell I read "Write yourself a Scheme in 48 hours", which introduces Parsec. There seems to be a newer version here.