Tony Davie wrote:
>
> analyse "abbe" = an array, pos, such that pos ! 'a' == 0, pos ! 'b' ==1, pos !
> 'e' ==3, and all other pos ! i are -1 (say). [Note my correction to the
> specification below]
-- <CODE>
import Monad
import Array
firstIndexes :: (Ix a, Num b, Enum b) => (a,a) -> [a] -> Array a (Maybe
b)
firstIndexes bnds l = accumArray mplus Nothing bnds (zip l (map Just
[0..]))
analyse l = firstIndexes ('a','z') l
-- </CODE>
That's the most efficient way I know to do it in Haskell.
Matt Harden
