On Sat, Apr 5, 2008 at 7:32 PM, Brandon S. Allbery KF8NH <[EMAIL PROTECTED]> wrote> > On Apr 5, 2008, at 15:07 , John M. Dlugosz wrote: > > > What is a "list comprehension"? I've seen that term bantered around here. > > > > The term comes from Haskell and Python; it's a shorthand notation for list > generation and filtering. > > [x | x <- some expression involving y, y = some range expression] -- > haskell syntax
You've got the order mixed up there. Variables are bound left-to-right on the right side of the bar: [ (x,y) | x <- [1..3], y <- replicate x "foo" ] Gives: [ (1,"foo"), (2,"foo"), (2,"foo"), (3,"foo"), (3,"foo"), (3,"foo") ] (replicate should be pretty obvious: replicate 4 0 = [0,0,0,0]) Luke
