Hi Miguel,

My intension about core is that it is a Haskell subset and since I'm writing a tool to translate Haskell to another language, core reduces significantly the cases I have to deal with.

That makes perfect sense, and using Core should definitely make your task easier.

I'm then converting Core AST to another AST (of other language). Some of the translation steps only need to pattern-matching over Core AST but others require some analysis of Core. For example, things like how many times a variable or a function are used inside a function definition.

In a few days there will be a release of the Uniplate library for Yhc Core, which should make these kind of transformations much easier. Much of it is already possible using Play - for example to see the number of times variable 'z' is used in an expression: length [() | Var i <- allCore x, i == "z"] In a few days, universe will give you the answer instead of allCore. Thanks Neil

-----Mensagem original----- De: Neil Mitchell [mailto:ndmitchell@gmail.com] Enviada: quarta-feira, 13 de Junho de 2007 16:01 Para: José Miguel Vilaça Cc: yhc@haskell.org Assunto: Re: [Yhc] Haskell file to YHC.Core AST

Hi

...

I see that I can read a .hs file and output a .ycr by calling in a shell yhc File.hs –core

You might also want to pass -linkcore instead, depending on your use - some people choose -core, some -linkcore.

...

main = system "yhc File.hs -core" >> loadcore "File.ycr" >>= writeFile "File.txt" . show . trans

...

First, the YHC documentation at http://www.cs.york.ac.uk/fp/yhc/snapshot/docs/doc-index.html do not know about a loadcore function. Is it available ?

It is, and its in the index, but isn't being searched for. Whats particularly worrying is that I wrote the code that does the searching, so its most likely my fault... See http://www.cs.york.ac.uk/fp/yhc/snapshot/docs/Yhc-Core-Serialise.html#v%3Alo adCore

...

Second, is there a way of substituting the call to system by some Haskell code?

No, not currently. I have found the system call to be perfectly sufficient.

...

Third. I'm having troubles with the binary version for windows given in http://www.haskell.org/haskellwiki/Yhc/Snapshots . For a Main.hs file containing Where C:\tools\yhc is where I unpack the .zip file downloaded.

If you are developing Yhc programs you will also need to check out the darcs repository (but not compile it). Then when doing linking you'll need to include something like:

ghc --make Main.hs -id:\sources\yhc\current\src\libraries\core -id:\sources\yhc\current\depends\play

Where d:\sources\yhc\current is the Yhc darcs directory. We'll be releasing a .cabal package shortly which means this step will no longer be necessary, but shouldn't be too hard for now.

Any hints on what you are hoping to do with Yhc.Core? We might be able to provide further information, and will certainly be interested to see the results :)

Thanks

Neil