26 Dec
2007
26 Dec
'07
1:30 p.m.
Well I certainly hope the standard defines that both fred and bob will only be evaluated once, because my programs depend on that :) Peter Neil wrote:
fred = 2 + 2 bob = fred + fred In a Haskell implementation fred would be evaluated once to 4, then used twice. The 2+2 would only happen once (ignore defaulting and overloaded numerics for now). Is this sharing mandated by the standard? (I don't think so) Is there some paper that describes why this is desirable, and gives any detail? Do all Haskell compilers support the sharing?