On Sun, 13 May 2007, David Roundy wrote:
I was just contemplating hashes, and it occurred to me that it would be
nice to be able to compute the hash of a lazily constructed bytestring and
lazily consume its output without requiring the whole string to ever be in
memory. Or in general, it'd be nice to be able to perform two simultaneous
consumptions of a lazy list without requiring that the entire list be
stored.
How about reading the same file twice?
do l1 <- readFile "foo"
l2 <- readFile "foo"
let len = length l1
writeFile "bar" l2
...
Another solution would be loop fusion:
do l <- readFile "foo"
len <- writeFileAndComputeLength "bar" l
...
A compiler might be able to do that for you.
Tom
--
Tom Schrijvers
Department of Computer Science
K.U. Leuven
Celestijnenlaan 200A
B-3001 Heverlee
Belgium
tel: +32 16 327544
e-mail: [EMAIL PROTECTED]
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