-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1

On 5/6/11 14:57 , Mike Meyer wrote:

> I'm filling a functional itch that Haskell isn't scratching. I'm

> looking for a function to take a list of functions, and apply them all

> to a value. The signature is obvious :: [a -> b] -> a -> [b], and it's

> nearly trivial to write (\fs a -> map ($ a) [fs]), but Haskell has

> most useful list functions already provided.

It's there, but it's not a dedicated function; it's "sequence" applied to

the environment monad (-> e).

Prelude Control.Monad.Reader> :t sequence

sequence :: (Monad m) => [m a] -> m [a]

Prelude Control.Monad.Reader> :t sequence [(+1),(*2),(`subtract` 3)]

sequence [(+1),(*2),(`subtract` 3)] :: (Num a) => a -> [a]

- --

brandon s. allbery [linux,solaris,freebsd,perl] allbery.b at gmail.com

system administrator [openafs,heimdal,too many hats] kf8nh

-----BEGIN PGP SIGNATURE-----

Version: GnuPG v1.4.11 (Darwin)

Comment: Using GnuPG with Mozilla -

http://enigmail.mozdev.org/iEYEARECAAYFAk3ESD0ACgkQIn7hlCsL25XFeQCgnD2GTT4sjYKJ5Nw9QGG+qGJb

8NkAoKq07s8sUxjqw3CthG/0HNiKwnlU

=ifKQ

-----END PGP SIGNATURE-----