Prelude> let f = \x->\y->\z->x (map (+ y) z) <interactive>:1: parse error on input `->\' Prelude> let f = \x-> \y-> \z-> x (map (+ y) z) Prelude> Are the spaces really necessary, or is this a bug? Thanks, Bryn
Yes, the spaces are necessary. This is because of the maximal munch rule; it assumes that '->\' is an identifier. In fact, you can define it as such: Prelude> let (->\) a b = a + b Prelude> 5 ->\ 6 11 Prelude> You can of course write Prelude> let f = \x y z -> x (map (+y) z) if you wish. -- Hal Daume III "Computer science is no more about computers | hdaume@isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume On Wed, 16 Oct 2002, Bryn Keller wrote:
Prelude> let f = \x->\y->\z->x (map (+ y) z) <interactive>:1: parse error on input `->\' Prelude> let f = \x-> \y-> \z-> x (map (+ y) z) Prelude>
Are the spaces really necessary, or is this a bug?
Thanks,
Bryn
_______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Ah, thanks. Hal Daume III wrote:
Yes, the spaces are necessary. This is because of the maximal munch rule; it assumes that '->\' is an identifier. In fact, you can define it as such:
Prelude> let (->\) a b = a + b Prelude> 5 ->\ 6 11 Prelude>
You can of course write
Prelude> let f = \x y z -> x (map (+y) z)
if you wish.
-- Hal Daume III
"Computer science is no more about computers | hdaume@isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume
On Wed, 16 Oct 2002, Bryn Keller wrote:
Prelude> let f = \x->\y->\z->x (map (+ y) z) <interactive>:1: parse error on input `->\' Prelude> let f = \x-> \y-> \z-> x (map (+ y) z) Prelude>
Are the spaces really necessary, or is this a bug?
Thanks,
Bryn
_______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
-- Bryn Keller Sr. Software Engineer Jenkon, Inc. Vancouver, WA 360.256.4400 brk@jenkon.com www.jenkon.com
participants (2)
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Bryn Keller -
Hal Daume III