I am getting a list of lists from chop9.  I want to somehow filter each element in the list.  How do I do that.

I have encoded binary data eg [1,1,0,0,1,0] etc

Each 9th bit is a parity bit which is checked using this function:

type Bit = Int

paritychecker :: [Bit] -> Bool

paritychecker xs | length xs == 9 && ((sum (init xs)) `mod` 2) == (last xs) = True

                 | otherwise = False

In the stream (the list) I use chop to retrieve each block of 9 bits as in:

chop9 :: [Bit] -> [[Bit]]

chop9 [] = []

chop9 bits = take 8 bits : chop9 (drop 8 bits)

I have been playing with this sort of thing:

filter paritychecker ??? chop9 [1,0,0,0,1,1,1,0,0,...]

But doesn't work.

I want to end up with all the 9 bit chunks which pass the filter.  So my end type should be [[Bit]]

paritychecker requires a list - eg [Bit] . So I want to run paritychecker on each element returned from chop9.  How do I do that?

Example encoded data stream:

[1,0,0,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,0,1,0,0,1,1,0,0,0,1,0,0,1,1,1,0,0,0,0,1,0,1,1,1,0,0,1,0,0,1,1,1,1,0,1]

Angus