[Haskell-cafe] missing optimization for (++)

[Ben Franksen]

Am 04.03.2018 um 22:40 schrieb Josef Svenningsson:
> The rule "foldr/id" will replace 'foldr (:) [] xs' with 'xs'.

Ah, thanks a lot. That was the missing piece. And good to know, too,
this means I can avoid a number of case distinctions I thought I needed
for optimum performance.

Cheers
Ben