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It's interesting because when I read about how Rust can rewrite iterators code into more performant direct loops I thought about Joe's blog posts that mentioned

• pygy_ 9y ago
  LuaJIT does the same, down to an absurd level. From the luafun library readme (which uses iterators under the hood): https://github.com/luafun/luafun https://github.com/luafun/luafun ———— > Let's see an example: > -- Functional style > require "fun" () > -- calculate sum(x for x^2 in 1..n) > n = 100 > print(reduce(operator.add, 0, map(function(x) return x^2 end, range(n)))) 328350 > -- Object-oriented style > local fun = require "fun" > -- calculate sum(x for x^2 in 1..n) > print(fun.range(n):map(function(x) return x^2 end):reduce(operator.add, 0)) 328350 > Lua Fun takes full advantage of the innovative tracing JIT compiler to achieve transcendental performance on nested functional expressions. Functional compositions and high-order functions can be translated into efficient machine code. Can you believe it? Just try to run the example above with `luajit -jdump` and see what happens: -- skip some initilization code -- ->LOOP: 0bcaffd0 movaps xmm5, xmm7 0bcaffd3 movaps xmm7, xmm1 0bcaffd6 addsd xmm7, xmm5 0bcaffda ucomisd xmm7, xmm0 0bcaffde jnb 0x0bca0024 ->5 0bcaffe4 movaps xmm5, xmm7 0bcaffe7 mulsd xmm5, xmm5 0bcaffeb addsd xmm6, xmm5 0bcaffef jmp 0x0bcaffd0 ->LOOP ---- TRACE 1 stop -> loop > The functional chain above was translated by LuaJIT to (!) one machine loop containing just 10 CPU assembly instructions without CALL.