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Performance of contextual variables (Score:1)
Hi patrick
while I agree that contextual variables are a very neat solution, do they not make using these variables very slow?
Even when not using contextual variables explicitly, every use of say() would need to check that no caller has overridden the value of $*OUT
Clint
Re:Performance of contextual variables (Score:2)
From what I can tell, contextuals don't appear to me to be all that much slower than ordinary lexicals. There might be a case where a deeply nested call stack could increase the search time, but I suspect that will be rather rare.
Beyond that, there are all sorts of ways to optimize for the cases where speed ends up being more important than flexibility. For example, a block that is going to make a lot of calls to say() can do:
and this will reduce the number of caller contexts that say() will need to search in order to find $*OUT.
I suspect it will even be possible for compilers to detect frequent use of say() in a set of blocks and optimize the contextual lookup similar to what I've done above.
Pm
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