[Haskell-beginners] program not running lazily

Rein Henrichs rein.henrichs at gmail.com
Thu Jan 21 18:42:43 UTC 2016


But not that doing so will cause the program to have an exponential runtime
as each new ys must be repeatedly traversed to append a [y].. The
alternative is to *unfold* your list by recursing on the right hand side of
the (:) to add new elements.

On Thu, Jan 21, 2016 at 5:43 AM Doug McIlroy <doug at cs.dartmouth.edu> wrote:

> Each time you find another good 9-mer, you add it to
> the head of the list. This means that the ultimate
> list will be in reverse order of discovery: the first element
> to be printed is the last one to be found.  To get
> output in the order it was discovered, build the
> output by ys++[y] rather than y:ys.
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