Re: [ANN] Lua Fun - a functional programming library for tracing JIT compiler

[Greg Fitzgerald <garious@...>]

> sum(map(function(x) return x^2 end, take(n, tabulate(math.sin(x)))))

Wow, LuaJIT translates that to one loop?  amazing!  Does it implement
stream fusion?

http://citeseer.ist.psu.edu/viewdoc/summary?doi=10.1.1.104.7401


How general is this mechanism?  Will it fuse maps over trees?

Thanks,
Greg

On Wed, Nov 20, 2013 at 10:41 AM, Roman Tsisyk <roman@tarantool.org> wrote:
>
> I'm happy to announce the release of Lua Fun [1] - a high-performance functional
> programming library designed for superb LuaJIT tracing just-in-time compiler.
>
> The library provides a set of more than 50 programming primitives like `map`,
> `filter`, `reduce`, `zip`, etc. to help you writing simple and efficient code.
>
> Lua Fun takes the full advantage of the innovative tracing JIT compiler [2] to
> achieve transcendental performance on functional compositions and high-order
> functions. Functional expressions can be compiled into efficient asm code!
>
> An example:
>
>     require "fun" ()
>     n = 100
>     ans = sum(map(function(x) return x^2 end, take(n, tabulate(math.sin(x)))))
>     -- calculate sum(sin(x)^2 for x in 0..n-1)
>     print(ans)
>
> LuaJIT 2.0 translates code above to:
>
>     -- some initilization code --
>     ->LOOP:
>     394cffd0  movsd [rsp+0x8], xmm7
>     394cffd6  addsd xmm4, xmm5
>     394cffda  ucomisd xmm6, xmm1
>     394cffde  jnb 0x394c0028        ->6
>     394cffe4  addsd xmm6, xmm0
>     394cffe8  addsd xmm7, xmm0
>     394cffec  fld qword [rsp+0x8]
>     394cfff0  fsin
>     394cfff2  fstp qword [rsp]
>     394cfff5  movsd xmm5, [rsp]
>     394cfffa  mulsd xmm5, xmm5
>     394cfffe  jmp 0x394cffd0        ->LOOP
>     ---- TRACE 1 stop -> loop
>
> Simple, Efficient and Functional.
> In Lua. With JIT.
>
> Lua Fun is fully documented [2] and tested. A Rockspec is available [3].
> This is the first public release. Feedback is very welcome!
>
> [1] https://github.com/rtsisyk/luafun
> [2] http://luajit.org/luajit.html
> [3] http://rtsisyk.github.io/luafun
> [4] https://raw.github.com/rtsisyk/luafun/master/fun-scm-1.rockspec
>
> Thank you for your attention!
> Have Fun!
>
> --
> WBR,
>   Roman Tsisyk <roman@tarantool.org>
>   http://tarantool.org/ - an efficient in-memory database and a Lua application server