-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Fri, Jun 20, 2003 at 06:23:42PM -0700, Brett Kelly wrote:
now, i know i've got a syntax problem, because i'm pretty sure my logic is correct (or at least MOSTLY correct).
Try: pyindex :: Eq a => a -> [a] -> Maybe Int pyindex c l = pyindex' 0 l where pyindex' _ [] = Nothing pyindex' n (x:xs) = if (x == c) then Just n else pyindex' (n+1) xs then, in ghci: Pyindex> pyindex 'e' "brett" Just 2 Pyindex> pyindex 'm' "brett" Nothing Pyindex> pyindex 't' "brett" Just 3 hope this helps. mike - -- mike castleman / m at mlcastle dot net / http://mlcastle.net / (646) 382-7220 aolim: mlcastle / icq: 3520821 / yahoo: mlc000 please avoid sending me microsoft word, excel, or powerpoint documents. see http://www.gnu.org/philosophy/no-word-attachments.html for more info. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+87lKrbXc6n5AevkRAtHwAJ9ARgtMHxWmlHWdgvOmIOFdi0W6FwCeOnLk TXyz94uSH3RufPx7xpZhtX4= =98Ym -----END PGP SIGNATURE-----