Reliability of trace?
Colin Paul Adams
colin at colina.demon.co.uk
Tue Mar 10 11:14:40 EDT 2009
>>>>> "Isaac" == Isaac Dupree <ml at isaac.cedarswampstudios.org> writes:
Isaac> Colin Paul Adams wrote:
>> I'm trying to use Debug.Trace to debug some tree-walking that
>> I've written.
>> It seems to me that I am missing some traces on intermediate
>> function calls. I guess that ghc is re-arranging the code in
>> such a way that some of these intermediate calls
>> disappear. Anyway of stopping this? I already specify -O0.
Isaac> right; with -O0 you get pretty much the exact amount of
Isaac> sharing that your code suggests
Isaac> are you sure those traces are attached to expressions that
Isaac> are being evaluated at all? Remember how lazy Haskell
I was was absolutely sure of what was happening, I wouldn't need to
run a trace :-).
But I do know certain things about what is happening, and I cannot see
how the code can avoid some of these trace statements.
Anyway, I think I know how to fix my code now.
When I've done it, I'll put the traces back on, and see if I can
understand what is happening. If not, I'll post the code here, and ask
the question again, for future enlightenment.
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