On 22 April 2015 at 10:31, Shishir Srivastava
Hi,
Continuing on from my previous question about powerset using filterM - Thanks to Alexey and Chaddaï.
filterM is implemented as below -
----
filterM _ [] = return [] filterM p (x:xs) = do flg <- p x ys <- filterM p xs return (if flg then x:ys else ys)
---
I still don't quite understand how 'flg' being a boolean [] is used in the last 'if statement' of implementation because when I try to do the same thing outside in GHCi it fails miserably even though I am casting it to [Int] -
-- return (if [True, False] then "4" else "3")::[Int] --
`flg` has type `Bool`, not `[Bool]`.
Offtopic : Also if someone can explain how do I reply to individual mails/responses to my queries because I only get a digest on my gmail and there is no way to isolate and reply to individual mails either this list's page or from digest.
I suspect you'll have to go to the list server and modify your settings there; it sounds like you have instructed it to send digests, so you need to change it to send every individual email. Alternatively you switch to a more capable mail reader, e.g. mutt, which handles digests better than gmail does. /M -- Magnus Therning OpenPGP: 0xAB4DFBA4 email: magnus@therning.org jabber: magnus@therning.org twitter: magthe http://therning.org/magnus