* Serge D. Mechveliani <mech...@botik.ru> [2012-10-17 19:02:37+0400]
> People,
> consider the following contrived program for division with remainder:
>
> ----------------------------------------------------------------
> qRem :: Int -> Int -> (Int, Int)
> qRem m n = if m < 0 || n <= 0 then error "\nwrong arguments in qRem.\n"
> else qRem' 0 m
> where
> qRem' q r = if r < n then (q, r) else qRem' (succ q) (r - n)
You need to force evaluation of 'q' here, otherwise it becomes a growing
chain of 'succ' applications.
E.g.
qRem' q r = if r < n then (q, r) else (qRem' $! succ q) (r - n)
Roman
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