[Haskell-beginners] Library source

Dave Bayer bayer at cpw.math.columbia.edu
Wed Mar 10 09:07:07 EST 2010

On Mar 8, 2010, at 1:05 PM, Stephen Tetley wrote:

> Haven't the 'standard' libs (aka the Hierarchical libs)  they always
> been here with a GHC install?
> <ghc-version>/doc/html/...
> Html docs for GHC, Haskell Hierarchical Libraries (with marked-up) source, Cabal

First, in GHC 6.12 there are fewer standard libraries: Only those needed to build GHC itself. Before 6.12 one could learn Haskell and get many things done without venturing into Cabal libraries. Now many of the libraries one took as "standard" in the past are Cabal installs. Meanwhile, as one gains experience with Haskell one ventures beyond the "standard" libraries, and also expects full documentation.

Here's a ticket (not started by me) indicating that Cabal's default is not to make all possible documentation, and this default is hard to change:


I found this ticket because I was missing documentation that I expected. Can't tell you which files now; after my work-around I have everything that I expect.

Don't get me wrong, building from source then using "cabal install" is by far the best option I know. I just wish that all options (every platform-specific binary install, Haskell Platform, source then cabal install) would provide every conceivable Haddock HTML file with links.

In calculus we teach students to look both at critical points and the endpoints of an interval for optima. I'm saying here that the optimum is the "document all source code" end of the interval. It's an easy principle to articulate, and we don't follow it. I'm asking why not, and speculating that it's simply a dated habit that hasn't been reexamined recently. Hey, my primary drives are all solid state, and I have enough room for source code. In the era of $80 TB drives, this seems a no-brainer.

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