Stephen Tetley schrieb:
On 2 March 2010 19:20, Sean Leather <leat...@cs.uu.nl> wrote:
My question is simple:
How do you rewrite your code to improve it?
Hi Sean - excellent question!
Some things I do...
Quite often I do a 'worker-wrapper-lite' rewrite i.e. change a
function to perform its recursive work in a step rather than calling
the function again with all the arguments, e.g.
para :: (a -> ([a], b) -> b) -> b -> [a] -> b
para phi b = step
where step [] = b
step (x:xs) = phi x (xs, step xs)
rather than...
para_ :: (a -> ([a], b) -> b) -> b -> [a] -> b
para_ phi b [] = b
para_ phi b (x:xs) = phi x (xs, para_ phi b xs)
I'm doing no type changing to improve efficiency so it isn't a real
worker-wrapper, but I usually find the 'step' style more pleasing,
especially when the code is somewhat more complicated than the
paramorphism above.
Me too.
http://haskell.org/haskellwiki/Top-level_vs._local_recursion
I have written some articles in Category:Style on that topic.
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