[Haskell-cafe] lambda abstraction
wren ng thornton
wren at freegeek.org
Mon Jun 6 04:52:28 CEST 2011
On 6/5/11 1:33 PM, Brandon Allbery wrote:
> On Sun, Jun 5, 2011 at 07:45, Patrick Browne<patrick.browne at dit.ie> wrote:
>> Are the following two functions equivalent? (i.e. do they describe the
>> same computation)
>> let add1 a = a + 2
>> let add2 = \ a -> a + 2
> Mostly. The monomorphism restriction can cause Haskell to restrict
> the type of the second to "Integer -> Integer".
Also, in GHC 7 they may have different behavior with regards to
inlining. That is, GHC 7 changed its rules to only inline when the
arguments to the left of "=" have been saturated (I'm not sure how this
interacts with the INLINE or INLINEABLE pragma).
Whether this operational difference would count as "different" depends
on how fine-grained you want your operational semantics to be. It
wouldn't show up in the denotational semantics side of things.
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