Text.Parsec.Language.LanguageDef - Add spaceChar

[minad]

Adds spaceChar field to the LanguageDef record. This helps if one builds whitespace sensitive parsers using Text.Parsec.Token. This should resolve #24

[mrkkrp]

@minad, Could you add similar changes to Parsec's fork I'm working on —
megaparsec?

I can of course add these changes myself (I'm going to fix all issues and
then add complete QuickCheck test suite for a start), but I would like you
to add them via pull request mechanism, and add you to AUTHORS.md file.

Thanks.

[minad]

Hi @mrkkrp! Thx to let me know about megaparsec. What is exactly the problem with parsec? Is it deprecated somehow? Are you going to collaborate with @aslatter to merge the projects afterwards again?

Concerning this patch: I am not totally convinced if it is necessary. For example indent based language parsing can be done in a more intelligent way. See this code snippet by @sdiehl:

https://github.com/sdiehl/write-you-a-haskell/blob/master/chapter9/layout/Layout.hs

Maybe you could consider adding an IndentParser or LayoutParser to Megaparsec?

[mrkkrp]

@minad, well, the problem with parsec is basically that it's quite old and could be certainly refreshed, but I would never start something like that if the current maintainer were.. er.. more active. There are quite a few bugs and nothing is being done. I've written tests for one bug, and opened PR, but after some point @aslatter disappeared and we cannot get anything done. There are too many things I want to do and I can't. So I started this project to hack it at my full speed. Also, I don't think it will be merged because megaparsec doesn't care about backward compatibility. Thanks for the link, I will see what's the best way to handle the problem in megaparsec.

[minad]

Hi Mark, maybe you could come to the irc channel then we could quickly discuss?

[mrkkrp]

@minad, sure, but it's 2 a.m. here, so I'm going to sleep right now. Just tell me your nick there, and I will ping you later, OK?

[mrkkrp]

@minad, sorry, I couldn't catch you at irc today. If you have ideas or propositions about this issue, please feel free to post them here: mrkkrp/megaparsec#5. Today I've been fixing parsing of numbers and also fixed two bugs. I think I will get to this problem soon too.

[minad]

solved by megaparsec I guess