> Simon Marlow wrote:
>
> | lines :: String -> [String]
> | lines s = lines' s ""
> | where
> | lines' [] acc = [acc]
> | lines' ('\n':s) acc = reverse acc : lines' s ""
> | lines' (c:s) acc = lines' s (c:acc)
> |
> | This one is more than twice as fast as the foldr
> | version, despite the fact that it needs to reverse the
> | accumulating parameter for each line.
>
> Unfortunately, it is less lazy too, so it will blow out of
> heapspace on very long lines.
Yes, so it is. But in fact, so is Wolfram's foldr version.
head (head (lines ('x':error "urk!")))
should yield 'x' according to the report definition.
Simon
