Tks Arjun, This is what I want. Thanks very much. Bright --- Arjun Guha <guhaarju@grinnell.edu> wrote:
Try this:
remove theList toRemove = filter (\x -> not (elem x toRemove)) theList
-Arjun
On Mar 27, 2005, at 18:28, Bright Sun wrote:
Hi,
Tks, this is not what I wanted.
I want remove pairs list,
[(5,1),(4,1),(3,1),(2,1),(1,1)] remove [(2,1),(1,1)] [(5,1),(4,1),(3,1)]
so pairs [(2,1),(1,1)] removed.
Tks.
--- Pierre Barbier de Reuille <pierre.barbier@cirad.fr> wrote:
One answer is the infix operator (\\) defined in the List module (or in Data.List ...)
But it's in ont of the "set" operations. For example try :
[1..10] \\ [3..6] [1,2,7,8,9,10]
But also :
([1..10]++[1..10]) \\ [3..6] [1,2,7,8,9,10,1,2,7,8,9,10]
So _all_ the elements with values in [3..6] where removed !! If that's what you want ! Perfect ... if not : what do you want exactly ? List substraction is not uniq.
Pierre
Bright Sun a �crit :
In Haskell, ++ can spends second list argument onto the end of first list argument. How to substract the second list from the first list?
For example, [(5,1),(4,1),(3,1),(2,1),(1,1)] substract [(2,1),(1,1)] I want to get result list: [(5,1),(4,1),(3,1)]
Tks.
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