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Category Archives: Haskell

Haskell platform pitfalls #1

I’ve started playing with Haskell platform, and immediatelly had some issues. Here are some of them, recorded so if I’ll forget I don’t need to solve them again.

  1. After installation of a platform I knew I need cabal. Haskell wiki says it is there, but I didn’t knew where to look. Finally I’ve found it: in Haskell Platform directory there is a place with path lib/extralibs/bin. It seems that I need to read full platform documentation before starting using it
  2. OK, with cabal I’ve tried to install snap framework. It stumbled on ghc-paths component, complaing that it “cannot configure”. I’ve checked and found that this component is used to find path where Haskell Platform is installed. I’ve checked my path and there were an entry for Haskell bin directory. A mystery. I’ve tried to run ghc from that command line (Far Manager, actually) which I’ve used to start cabal, and no, ghc was not found. I’ve typed ‘path’, and an entry for Haskell Platform was missing. I’ve remembered that command line was started before I’ve installed Haskell Platform, so changes in system path were not seen. Restarting command line solved that problem
  3. Next package I’ve tried to install was hxt. It complained that it cannot determine version of ghc. It took me a while to figure out that command line should be started with admin rights.
  4. I’ve tried to create a blank project with snap. Just create a folder and type ‘snap init’. Then I’ve tried to build that project with cabal. Oops, “can’t parse name”. It took me some time to guess that it doesn’t like symbol ‘-‘ in the name of that folder

So far so good.