On Sat, Feb 04, 2006 at 11:58:15AM -0800, John Meacham wrote:
On Sat, Feb 04, 2006 at 03:11:10PM +0100, John Hughes wrote:
I noticed ticket #55--add parallel list comprehensions--which according to the ticket, will probably be adopted. I would argue against.
I disagree. :) I use them all the time and find them very useful.
however, I do agree with some of your criticisms and would be interested if we can think of some sort of generalization of them.
Hmmm... you can use zip, can't you? If you want to zip arbitrary number of lists, there is a trick that can help: zApp = zipWith ($) then zip3 [1..4] [2..] [3..] is equivalent to: repeat (,,) `zApp` [1..4] `zApp` [2..] `zApp` [3..] where the latter is easily extensible. You could also only use zip, if you don't mind working on nested pairs: zip (zip [1..4] [2..]) [3..] I don't use parallel list comprehensions. I am also zipping trees, and PLCs don't help me here. Best regards Tomasz -- I am searching for programmers who are good at least in (Haskell || ML) && (Linux || FreeBSD || math) for work in Warsaw, Poland