[Haskell-beginners] Issue installing reactive-banana-5.0.0.1

[Miguel Negrao]

A 01/05/2012, às 19:24, Heinrich Apfelmus escreveu:

> Miguel Negrao wrote:
>> Since I have wxWidgets 2.9.3 installed already I might as well give
>> it a try with reactive-banana-0.6. I installed wx-0.90 and
>> wxcore-0.90 and reactive-banana-0.6.0 (from git) without issues. I
>> couldn’t install reactive-banana-wx though, I get this error:
>> Configuring MissingH-1.1.1.0...
>> Warning: This package indirectly depends on multiple versions of the same
>> package. This is highly likely to cause a compile failure.
>> package regex-base-0.93.2 requires mtl-2.0.1.0
>> package parsec-3.1.1 requires mtl-2.0.1.0
>> package parsec-3.1.1 requires mtl-2.1
>> package hslogger-1.1.5 requires mtl-2.1
>> package MissingH-1.1.1.0 requires mtl-2.1
>> package MissingH-1.1.1.0 requires parsec-3.1.1
>> package network-2.3.0.5 requires parsec-3.1.1
>> package mtl-2.0.1.0 requires transformers-0.2.2.0
>> package mtl-2.1 requires transformers-0.3.0.0
>> Preprocessing library MissingH-1.1.1.0...
>> Preprocessing executables for MissingH-1.1.1.0...
>> Building MissingH-1.1.1.0...
>> <command line>: cannot satisfy -package-id parsec-3.1.1-178bb186a8cbec1a8bf6b3192212c18e:    parsec-3.1.1-178bb186a8cbec1a8bf6b3192212c18e is shadowed by package parsec-3.1.1-fb91ea6e6c1f9c50292782ec985e5f9a
>>   (use -v for more information)
>> Updating documentation index
>> /Users/miguelnegrao/Library/Haskell/doc/index.html
>> cabal: Error: some packages failed to install:
>> MissingH-1.1.1.0 failed during the building phase. The exception was:
>> ExitFailure 1
>> cabal-macosx-0.2 depends on MissingH-1.1.1.0 which failed to install.
>> reactive-banana-wx-0.6.0.0 depends on MissingH-1.1.1.0 which failed to
>> install.
> 
> Fortunately, this time it's not my fault. :)
> 
> You ran into a cabal problem with a package depending on multiple versions of the same package. The culprit seems to be  regex-base . I suggest you try
> 
>    cabal install regex-base parsec-3.1.1 \
>        --reinstall --constraint='mtl == 2.1'
> 
> to resolve this issue.

That installs regex-base-0.93.2 with no errors.

> Then try installing  reactive-banana-wx  again.

But then I get the same error installing reactive-banana-wx.
> 
> 
>> ps: Does reactive-banana also have time functions like it is
>> described in conal’s papers ? i.e. can I just animate something with
>> a function like cos (t) or do I have to explicitly create timers
>> myself ?
> 
> No, you have to create timers yourself. It's not very difficult, though, you can just create a wxWidget and listen to its  command  event.

Is any generality lost because of this or are the approaches equivalent ? 

best,
Miguel Negrão