Talk:Blow your mind
Name?
Is there a better name for this page? —Ashley Y 00:55, 2 March 2006 (UTC)
i completely agree, the name pretty much sucks. but what i really wanted, was to compile a collection of "idioms" that would enlarge the readers perception of what is possible in Haskell and how to go about it. so, i'll have to find a name that reflects this plan. —--J. Ahlmann 14:13, 2 March 2006 (UTC)
List / String Operations
Should this:
transpose . unfoldr (\a -> toMaybe (null a) (splitAt 2 a))
be this instead:
transpose . unfoldr (\a -> toMaybe (not $ null a) (splitAt 2 a))
Polynomial signum and abs
A sensible option for signum and abs for polynomials (with coefficients from a field) would be
- signum -> the leading coefficient
- abs -> the monic polynomial obtained by dividing by the leading coefficient
As with the abs and signum functions for Integer and for Data.Complex (when restricted to a subring whose intersection with the real numbers is just the integers), the result of this signum is then a unit (ie, a value x for which there exists a y such that xy = 1), and we have
- signum a * abs a = a
- abs 1 = signum 1 = 1
- abs (any unit) = 1
- abs a * abs b = abs (a * b)
Polynomial negate
Why not:
negate = map negate