On 26/05/2011 07:56 PM, Andrew Coppin wrote:
On 26/05/2011 10:59 AM, Jacek Generowicz wrote:
Any comments on the relative efficiency of the above as compared to
A == B in the context of
data Foo = A | B | C | D | ... lots more ...
?
(I imagine that a Sufficiently Smart Compiler could reduce (==) ::
Person Person to just integer comparison.)
My understanding is that if you have a constructor with no fields, it
gets allocated as a compile-time constant. In other words, "C" is just a
pointer to a static data structure somewhere in the program binary, and
(==) effectively becomes pointer equity.
OTOH, I am not a GHC developer...
...and what I *should* of course have written is "go benchmark it". ;-)
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