Wow, uniplate is the library from my dreams :) I knew there should be easy, elegant and simple solution (I hate brute force, that's why I start using Haskell). Many thanks. 2009/3/26 Neil Mitchell :

Hi

...

f1 = foo 5 f2 = foo 8 f3 = foo 9

I want to extract a list [5, 8, 9] (suppouse function takes only one argument)

Firstly, use haskell-src-exts and Language.Haskell.Exts - its a much better library, deals with many extensions, and gives you everything Language.Haskell did.

...

parser works pretty good, but its output data type is terrible. As I understand, I need to extract all objects that looks like HsApp (HsVar (UnQual (HsIdent "foo"))) ....

It's trivial, if you use a generics solution, say Uniplate: http://community.haskell.org/~ndm/uniplate

[x | App foo x <- universeBi src, prettyPrint foo == "foo" ]

I often use prettyPrint to follow down Ident/Qual/UnQual paths without having to know as much of the data type. Using universeBi makes it easy to find everything that occurs everywhere.

If you attempt this without using a generics library, I'd say you are destined to fail.

Thanks

Neil

-- Best regards, Vasyl Pasternak

Actually, looking at the docs for UniplateStr[1], isn't there an error in the following example statement in the Queries section? vals x = [Val i | i <- universe x] Shouldn't that be: vals x = [i | Val i <- universe x] ? /jve 1. http://hackage.haskell.org/packages/archive/uniplate/1.2.0.3/doc/html/Data-G... On Thu, Mar 26, 2009 at 1:47 PM, minh thu wrote:

2009/3/26 Vasyl Pasternak :

...

Hi,

I want to parse haskell file to find all calls to function 'foo' and gathers a create a list of all argumets, which passed to it. E.g. from the following code:

f1 = foo 5 f2 = foo 8 f3 = foo 9

I want to extract a list [5, 8, 9] (suppouse function takes only one argument)

The most obvious way is to use Language.Haskell for this task. The parser works pretty good, but its output data type is terrible. As I understand, I need to extract all objects that looks like HsApp (HsVar (UnQual (HsIdent "foo"))) ....

The question is, is there a method to do it quickly or I have to process each object of different type separately ?

Have a look at this: http://neilmitchell.blogspot.com/2009/03/concise-generic-queries.html

Cheers, Thu _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Excellent! The black magic had me scratching my head until I realized it was broken magic. :) /jve On Thu, Mar 26, 2009 at 4:23 PM, Neil Mitchell wrote:

Hi John,

...

Actually, looking at the docs for UniplateStr[1], isn't there an error in the following example statement in the Queries section?

vals x = [Val i | i <- universe x]

Shouldn't that be: vals x = [i | Val i <- universe x]

Yep, you are indeed right. I've fixed the examples in the darcs version, and next time there is a release these changes will be incorporated.

Many thanks

Neil