neosnippet.vim/autoload/vital/_neosnippet/Data/List.vim
2015-05-11 22:11:55 -07:00

443 lines
11 KiB
VimL

" Utilities for list.
let s:save_cpo = &cpo
set cpo&vim
function! s:pop(list) abort
return remove(a:list, -1)
endfunction
function! s:push(list, val) abort
call add(a:list, a:val)
return a:list
endfunction
function! s:shift(list) abort
return remove(a:list, 0)
endfunction
function! s:unshift(list, val) abort
return insert(a:list, a:val)
endfunction
function! s:cons(x, xs) abort
return [a:x] + a:xs
endfunction
function! s:conj(xs, x) abort
return a:xs + [a:x]
endfunction
" Removes duplicates from a list.
function! s:uniq(list) abort
return s:uniq_by(a:list, 'v:val')
endfunction
" Removes duplicates from a list.
function! s:uniq_by(list, f) abort
let list = map(copy(a:list), printf('[v:val, %s]', a:f))
let i = 0
let seen = {}
while i < len(list)
let key = string(list[i][1])
if has_key(seen, key)
call remove(list, i)
else
let seen[key] = 1
let i += 1
endif
endwhile
return map(list, 'v:val[0]')
endfunction
function! s:clear(list) abort
if !empty(a:list)
unlet! a:list[0 : len(a:list) - 1]
endif
return a:list
endfunction
" Concatenates a list of lists.
" XXX: Should we verify the input?
function! s:concat(list) abort
let memo = []
for Value in a:list
let memo += Value
endfor
return memo
endfunction
" Take each elements from lists to a new list.
function! s:flatten(list, ...) abort
let limit = a:0 > 0 ? a:1 : -1
let memo = []
if limit == 0
return a:list
endif
let limit -= 1
for Value in a:list
let memo +=
\ type(Value) == type([]) ?
\ s:flatten(Value, limit) :
\ [Value]
unlet! Value
endfor
return memo
endfunction
" Sorts a list with expression to compare each two values.
" a:a and a:b can be used in {expr}.
function! s:sort(list, expr) abort
if type(a:expr) == type(function('function'))
return sort(a:list, a:expr)
endif
let s:expr = a:expr
return sort(a:list, 's:_compare')
endfunction
function! s:_compare(a, b) abort
return eval(s:expr)
endfunction
" Sorts a list using a set of keys generated by mapping the values in the list
" through the given expr.
" v:val is used in {expr}
function! s:sort_by(list, expr) abort
let pairs = map(a:list, printf('[v:val, %s]', a:expr))
return map(s:sort(pairs,
\ 'a:a[1] ==# a:b[1] ? 0 : a:a[1] ># a:b[1] ? 1 : -1'), 'v:val[0]')
endfunction
" Returns a maximum value in {list} through given {expr}.
" Returns 0 if {list} is empty.
" v:val is used in {expr}
function! s:max_by(list, expr) abort
if empty(a:list)
return 0
endif
let list = map(copy(a:list), a:expr)
return a:list[index(list, max(list))]
endfunction
" Returns a minimum value in {list} through given {expr}.
" Returns 0 if {list} is empty.
" v:val is used in {expr}
" FIXME: -0x80000000 == 0x80000000
function! s:min_by(list, expr) abort
return s:max_by(a:list, '-(' . a:expr . ')')
endfunction
" Returns List of character sequence between [a:from, a:to]
" e.g.: s:char_range('a', 'c') returns ['a', 'b', 'c']
function! s:char_range(from, to) abort
return map(
\ range(char2nr(a:from), char2nr(a:to)),
\ 'nr2char(v:val)'
\)
endfunction
" Returns true if a:list has a:value.
" Returns false otherwise.
function! s:has(list, value) abort
return index(a:list, a:value) isnot -1
endfunction
" Returns true if a:list[a:index] exists.
" Returns false otherwise.
" NOTE: Returns false when a:index is negative number.
function! s:has_index(list, index) abort
" Return true when negative index?
" let index = a:index >= 0 ? a:index : len(a:list) + a:index
return 0 <= a:index && a:index < len(a:list)
endfunction
" similar to Haskell's Data.List.span
function! s:span(f, xs) abort
let border = len(a:xs)
for i in range(len(a:xs))
if !eval(substitute(a:f, 'v:val', string(a:xs[i]), 'g'))
let border = i
break
endif
endfor
return border == 0 ? [[], copy(a:xs)] : [a:xs[: border - 1], a:xs[border :]]
endfunction
" similar to Haskell's Data.List.break
function! s:break(f, xs) abort
return s:span(printf('!(%s)', a:f), a:xs)
endfunction
" similar to Haskell's Data.List.takeWhile
function! s:take_while(f, xs) abort
return s:span(a:f, a:xs)[0]
endfunction
" similar to Haskell's Data.List.partition
function! s:partition(f, xs) abort
return [filter(copy(a:xs), a:f), filter(copy(a:xs), '!(' . a:f . ')')]
endfunction
" similar to Haskell's Prelude.all
function! s:all(f, xs) abort
return !s:any(printf('!(%s)', a:f), a:xs)
endfunction
" similar to Haskell's Prelude.any
function! s:any(f, xs) abort
return !empty(filter(map(copy(a:xs), a:f), 'v:val'))
endfunction
" similar to Haskell's Prelude.and
function! s:and(xs) abort
return s:all('v:val', a:xs)
endfunction
" similar to Haskell's Prelude.or
function! s:or(xs) abort
return s:any('v:val', a:xs)
endfunction
function! s:map_accum(expr, xs, init) abort
let memo = []
let init = a:init
for x in a:xs
let expr = substitute(a:expr, 'v:memo', init, 'g')
let expr = substitute(expr, 'v:val', x, 'g')
let [tmp, init] = eval(expr)
call add(memo, tmp)
endfor
return memo
endfunction
" similar to Haskell's Prelude.foldl
function! s:foldl(f, init, xs) abort
let memo = a:init
for x in a:xs
let expr = substitute(a:f, 'v:val', string(x), 'g')
let expr = substitute(expr, 'v:memo', string(memo), 'g')
unlet memo
let memo = eval(expr)
endfor
return memo
endfunction
" similar to Haskell's Prelude.foldl1
function! s:foldl1(f, xs) abort
if len(a:xs) == 0
throw 'foldl1'
endif
return s:foldl(a:f, a:xs[0], a:xs[1:])
endfunction
" similar to Haskell's Prelude.foldr
function! s:foldr(f, init, xs) abort
return s:foldl(a:f, a:init, reverse(copy(a:xs)))
endfunction
" similar to Haskell's Prelude.fold11
function! s:foldr1(f, xs) abort
if len(a:xs) == 0
throw 'foldr1'
endif
return s:foldr(a:f, a:xs[-1], a:xs[0:-2])
endfunction
" similar to python's zip()
function! s:zip(...) abort
return map(range(min(map(copy(a:000), 'len(v:val)'))), "map(copy(a:000), 'v:val['.v:val.']')")
endfunction
" similar to zip(), but goes until the longer one.
function! s:zip_fill(xs, ys, filler) abort
if empty(a:xs) && empty(a:ys)
return []
elseif empty(a:ys)
return s:cons([a:xs[0], a:filler], s:zip_fill(a:xs[1 :], [], a:filler))
elseif empty(a:xs)
return s:cons([a:filler, a:ys[0]], s:zip_fill([], a:ys[1 :], a:filler))
else
return s:cons([a:xs[0], a:ys[0]], s:zip_fill(a:xs[1 :], a:ys[1: ], a:filler))
endif
endfunction
" Inspired by Ruby's with_index method.
function! s:with_index(list, ...) abort
let base = a:0 > 0 ? a:1 : 0
return s:zip(a:list, range(base, len(a:list)+base-1))
endfunction
" similar to Ruby's detect or Haskell's find.
function! s:find(list, default, f) abort
for x in a:list
if eval(substitute(a:f, 'v:val', string(x), 'g'))
return x
endif
endfor
return a:default
endfunction
" Returns the index of the first element which satisfies the given expr.
function! s:find_index(xs, f, ...) abort
let len = len(a:xs)
let start = a:0 > 0 ? (a:1 < 0 ? len + a:1 : a:1) : 0
let default = a:0 > 1 ? a:2 : -1
if start >=# len || start < 0
return default
endif
for i in range(start, len - 1)
if eval(substitute(a:f, 'v:val', string(a:xs[i]), 'g'))
return i
endif
endfor
return default
endfunction
" Returns the index of the last element which satisfies the given expr.
function! s:find_last_index(xs, f, ...) abort
let len = len(a:xs)
let start = a:0 > 0 ? (a:1 < 0 ? len + a:1 : a:1) : len - 1
let default = a:0 > 1 ? a:2 : -1
if start >=# len || start < 0
return default
endif
for i in range(start, 0, -1)
if eval(substitute(a:f, 'v:val', string(a:xs[i]), 'g'))
return i
endif
endfor
return default
endfunction
" Similar to find_index but returns the list of indices satisfying the given expr.
function! s:find_indices(xs, f, ...) abort
let len = len(a:xs)
let start = a:0 > 0 ? (a:1 < 0 ? len + a:1 : a:1) : 0
let result = []
if start >=# len || start < 0
return result
endif
for i in range(start, len - 1)
if eval(substitute(a:f, 'v:val', string(a:xs[i]), 'g'))
call add(result, i)
endif
endfor
return result
endfunction
" Return non-zero if a:list1 and a:list2 have any common item(s).
" Return zero otherwise.
function! s:has_common_items(list1, list2) abort
return !empty(filter(copy(a:list1), 'index(a:list2, v:val) isnot -1'))
endfunction
function! s:intersect(list1, list2) abort
let items = []
" for funcref
for X in a:list1
if index(a:list2, X) != -1 && index(items, X) == -1
let items += [X]
endif
endfor
return items
endfunction
" similar to Ruby's group_by.
function! s:group_by(xs, f) abort
let result = {}
let list = map(copy(a:xs), printf('[v:val, %s]', a:f))
for x in list
let Val = x[0]
let key = type(x[1]) !=# type('') ? string(x[1]) : x[1]
if has_key(result, key)
call add(result[key], Val)
else
let result[key] = [Val]
endif
unlet Val
endfor
return result
endfunction
function! s:_default_compare(a, b) abort
return a:a <# a:b ? -1 : a:a ># a:b ? 1 : 0
endfunction
function! s:binary_search(list, value, ...) abort
let Predicate = a:0 >= 1 ? a:1 : 's:_default_compare'
let dic = a:0 >= 2 ? a:2 : {}
let start = 0
let end = len(a:list) - 1
while 1
if start > end
return -1
endif
let middle = (start + end) / 2
let compared = call(Predicate, [a:value, a:list[middle]], dic)
if compared < 0
let end = middle - 1
elseif compared > 0
let start = middle + 1
else
return middle
endif
endwhile
endfunction
function! s:product(lists) abort
let result = [[]]
for pool in a:lists
let tmp = []
for x in result
let tmp += map(copy(pool), 'x + [v:val]')
endfor
let result = tmp
endfor
return result
endfunction
function! s:permutations(list, ...) abort
if a:0 > 1
throw 'vital: Data.List: too many arguments'
endif
let r = a:0 == 1 ? a:1 : len(a:list)
if r > len(a:list)
return []
elseif r < 0
throw 'vital: Data.List: {r} must be non-negative integer'
endif
let n = len(a:list)
let result = []
for indices in s:product(map(range(r), 'range(n)'))
if len(s:uniq(indices)) == r
call add(result, map(indices, 'a:list[v:val]'))
endif
endfor
return result
endfunction
function! s:combinations(list, r) abort
if a:r > len(a:list)
return []
elseif a:r < 0
throw 'vital: Data:List: {r} must be non-negative integer'
endif
let n = len(a:list)
let result = []
for indices in s:permutations(range(n), a:r)
if s:sort(copy(indices), 'a:a - a:b') == indices
call add(result, map(indices, 'a:list[v:val]'))
endif
endfor
return result
endfunction
let &cpo = s:save_cpo
unlet s:save_cpo
" vim:set et ts=2 sts=2 sw=2 tw=0: