reti.vim でメモ化

vim

こんな感じで書けるかな。

[ソース]

function! s:memoize(func)
    let Func = a:func
    let cache = {}
    return reti#execute(join([
\       "if !has_key(cache, string(a:000))",
\       "    let cache[string(a:000)] = call(Func, a:000)",
\       "endif",
\       "return cache[string(a:000)]",
\   ], "|"), l:)
endfunction


let s:memoizer_cache = {}

function! s:memoizer(func)
    if !has_key(s:memoizer_cache, string(a:func))
        let s:memoizer_cache[string(a:func)] = s:memoize(reti#function(a:func))
    endif
    return s:memoizer_cache[string(a:func)]
endfunction


function! s:fib(n)
    let F = s:memoizer("s:fib")
    return a:n < 2 ? a:n
\        : F(a:n - 1) + F(a:n - 2)
endfunction

function! s:main()
    for n in range(1, 30)
        echo s:fib(n)
    endfor
endfunction
call s:main()

[出力]

1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597
2584
4181
6765
10946
17711
28657
46368
75025
121393
196418
317811
514229
832040