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Maybe loops are not fun in common lisp the? I had much fun with loops in PicoLisp. Julia also has similar macro capabilities to common lisp. > And it's much e

Maybe loops are not fun in common lisp the? I had much fun with loops in PicoLisp. Julia also has similar macro capabilities to common lisp. > And it's much easier to figure out what the function composition does than to write a loop vectorizer I probably agree but complicated loop vectorisation would probably expressed in Einstein tensor contraction notation such as Tullio.jl provides. I wonder a Fourier transform would look using function decomposition. @tullio F[k] := S[x] * exp(-impi/8 (k-1) * x) (k ∈ axes(S,1))

jhgb 5y ago
Loops are a lot of fun in Common Lisp, what with LOOP (https://gigamonkeys.com/book/loop-for-black-belts.html https://gigamonkeys.com/book/loop-for-black-belts.html), ITERATE (https://common-lisp.net/project/iterate/doc/Don_0027t-Loop-Iterate.html https://common-lisp.net/project/iterate/doc/Don_0027t-Loop-I...), and FOR (https://shinmera.github.io/for/ https://shinmera.github.io/for/). But their fundamental problem of trying to extract a "bird's eye view" of what you're actually trying to do remains here. Maybe a new iteration construct specifically supporting parallelization would help here. Some of these things might already work quite well, for example it should not be difficult to discern from (let me use ITERATE's example) (iterate (for el in list) (finding el minimizing (length el))) that you're computing argmin using a pure function, which should be easy to do in parallel, whereas the way you'd typically write this in C would be probably difficult for the compiler to confirm as such (it would have to look for pattern such as "if (f(current)<f(best)) { best=current; }" or something like that. (BTW have you seen another loop construct supporting argmin/argmax in another language? I haven't so far.) Whether this could be done somewhat generally and extensibly is something I have to ponder on.

jhgb 5y ago

Loops are a lot of fun in Common Lisp, what with LOOP (https://gigamonkeys.com/book/loop-for-black-belts.html https://gigamonkeys.com/book/loop-for-black-belts.html), ITERATE (https://common-lisp.net/project/iterate/doc/Don_0027t-Loop-Iterate.html https://common-lisp.net/project/iterate/doc/Don_0027t-Loop-I...), and FOR (https://shinmera.github.io/for/ https://shinmera.github.io/for/). But their fundamental problem of trying to extract a "bird's eye view" of what you're actually trying to do remains here. Maybe a new iteration construct specifically supporting parallelization would help here. Some of these things might already work quite well, for example it should not be difficult to discern from (let me use ITERATE's example) (iterate (for el in list) (finding el minimizing (length el))) that you're computing argmin using a pure function, which should be easy to do in parallel, whereas the way you'd typically write this in C would be probably difficult for the compiler to confirm as such (it would have to look for pattern such as "if (f(current)<f(best)) { best=current; }" or something like that. (BTW have you seen another loop construct supporting argmin/argmax in another language? I haven't so far.) Whether this could be done somewhat generally and extensibly is something I have to ponder on.