[Haskell-cafe] convert a list of booleans into Word*

[Aai]

Sorry, msb rigthmost

> Here's another approach for Bool lists with msb leftmost:
>
> bitsToInt :: [Bool] -> Integer
> bitsToInt = foldr((.(flip shiftL 1)).(+)) 0. map (fromIntegral.fromEnum)
>
>
>
> Hallo Paul.Brauner at loria.fr, je schreef op 30-09-09 11:18:
>   
>> Hello,
>>
>> I haven't found a function in hackage or in the standard library that
>> takes a list of booleans (or a list of 0s and 1s, or a tuple of booleans
>> or 0s and 1s) and outputs a Word8 or Word32.
>>
>> I have written one which seems very inefficient :
>>
>> toWord8 :: [Bool] -> Word8
>> toWord8 bs = go 0 0 bs
>>   where go n r []     = r
>>         go n r (b:bs) = go (n+1) (if b then setBit r n else clearBit r n) bs
>>
>> Is there a better way to do this out there ?
>>
>> (If it helps, i'm writting a toy compression algorithm, which outputs
>> binary as lists of booleans, and I'd like to output that in a file).
>>
>> Cheers
>> Paul
>> _______________________________________________
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>   
>>     
>
>   

-- 
Met vriendelijke groet,
=@@i

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