A guy w/ 10 weeks Rust experiance and already gave a talk at RustConf?!
(also, the author isn't a "guy")
From the luafun library readme (which uses iterators under the hood):
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.This one was particularly uninformed.