Using RIDE, what's the proper way to make a namespace that I can enter code into? Currently I'm going )ed ∘#.foo and then changing interface to namespace. What's the correct way?
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@Adám it's not as low as ÷3, maybe ÷2 ... ÷2.5, but still unexpected
@Adám I'm pretty sure Dyalog's impl of ⍳ already has the hell optimised out of it. But from my point of view your memory manager sucks as it was designed for a different age - before virtual memory, caches, and prefetching existed.
@Zacharý right, 0≤i<n, just like the result of % (modulo)
@Zacharý division and mod are terribly slow compared to addition and multiplication - that may be a bit surprising to you and me, but it's probably just obvious to those who spend their lifetimes squeezing performance out of cpus...
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another surprising fact: I thought I might be able to speed up some primitives, like the k equivalents of transpose and iota, by batch-allocating N lists (i.e. a k matrix) before filling them up
it turns out that's slower because when allocating I have to initialise the headers, and I end up touching memory in a bad interleaved jumpy pattern - first the headers, then the data
if the order is header0, data0, header1, data1, etc, prefetching takes effect and it's faster
@dzaima clang -03 definitely doesn't - in one case it generates instructions like cqo and idiv, in the other - a very tight loop with only inc, add, and mov
@Zacharý well, at least in my example, i stays in-bounds always and that optimization would be perfectly valid. I'd expect compilers to work very hard to get division/modulo out of the code
@Adám I didn't get around to trying using emacs for )ed until now. RIDE_EDITOR needs to be set as an environment variable in the shell (at first I thought it went along with the things like MAXWS until I realised it'd make little sense for it to be there). The temporary file it opens gets given a .dyalog extension which makes it trivial to autoload my input mode. For an undocumented feature it works really well
