[Haskell] Image manipulation

[Simon Peyton-Jones]

[Redirecting to ghc-bugs]

| > I'm not sure if the GC hack proposed by Wadler¹ that lets the garbage
| > collector replace "fst (a,b)" with "a" (and similar for other unchecked
| > selectors) counts as optimistic evaluation, but I wonder what the
| > status of this is.  GHC doesn't seem to do it, and I wonder if there
| > is any particular reason?  Too specific?
|
| GHC nominally does do it (look for 'selector thunks' in the RTS and
| commentary), but it doesn't work and we don't know why.
|
| http://hackage.haskell.org/trac/ghc/ticket/1038

That bug is alleged to be fixed.  Do you think it isn't?

Simon