make count(f,itr) count the number of nonzero; countnz(itr) -> count(itr) #20405
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base/reduce.jl
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| countnz(a) = count(x -> x != 0, a) | ||
| function count end | ||
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| function count{F}(pred::F, itr) |
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The static parameter shouldn't be necessary I would think
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It used to be a necessary hint in order to tell the compiler to type-specialize this on function arguments, I thought. (We want to make sure it does this, in order to inline identity etc.) Has that changed?
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I thought so but I'm probably wrong. @vtjnash?
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Hmm, I just tried it, and it seems to inline fine without the parameters now.
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IIRC, calling a function argument within the method body triggers specialization on the function argument (hence forcing specialization on pred via a static parameter is unnecessary in this case). Ref. #19137. Best!
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| Count the number of elements in `itr` for which predicate `p` returns `true`. | ||
| Count the number of elements in `itr` for which the function `p` returns |
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Would make sense to update find to use iszero too in a subsequent commit.
| """ | ||
| count(p, itr) -> Integer | ||
| count(itr) |
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Repeat -> Integer? BTW, should be written as ::Integer now.
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I don't think most of the Base docstrings have made the :: switch yet. IMO better to wait and do them all at once, keeping -> in the interim.
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| function count(pred, itr) | ||
| n = 0 | ||
| for x in itr |
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Not really related, but should we have a more efficient version for AbstractArray which would add @inbounds? When pred=identity in particular, a SIMD version should be much more efficient.
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Closing in favor of #20421 since the |
Closes #20403, #20404.