Hi
> | {-# INLINE foo #-}
> | foo = large
> |
> | bar x = if x then res else res
> | where res = foo
> |
> | By putting an INLINE on foo I am able to persuade it to be inlined
> | into the binding of bar, but I can't then persuade it to be inlined at
> | the let expression.
>
>
> I'm not certain what you mean here. I think you mean that in the above code
> you end up with
> bar x = let res = large in if x then res else res
> whereas what you wanted was
> bar x = if x then large else large
Yes, that is exactly it.
> In your example, you want 'res' to inline "first". You can get that by
> explicit control:
>
> {-# NOINLINE [0] foo #-}
>
> That says "don't inline foo before phase 0", which in turn gives time for
> 'res' to get inlined first. I'm not certain whether that'll help in your
> actual example.
It worked, with:
{-# INLINE [1] begin1 #-}
{-# INLINE begin2 #-}
I don't think this approach will compose particularly well, and in the
real case I was trying (not this reduced example) I don't think it
will work because there is some recursion and RULES involved. I'll
have another go with the full example in future.
I did however notice an issue while doing this work - in GHC 6.8.2 and
HEAD from Christmas.
{-# INLINE begin2
#-}
Temp.hs:7:1: lexical error at character '}'
In particular if you use the RULES example from the manual, then it
doesn't work.
Thanks
Neil
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