albertoruiz/hmatrix — pull request #26 by klao (2012-08-24 16:48:47+00:00)
Title: Clean up matrix map functions

I was trying to use the mapMatrixWithIndex, but had found it a bit messy. :) Description from commit:

Fixed type signatures on the mapMatrix* functions: they were too narrow,
and wrt. to indexing plain wrong.
Simplified the index converting helper, and directly implemented
mapMatrixWithIndex (without using the ineffient list monad trick).