func-closure を使わない実装

autoload/vital/__vital__/Data/List.vim

@@ -81,6 +81,7 @@ function! s:uniq_by(list, f) abort
  call add(result, x)
  call add(applied, y)
  endif
+ unlet x y
  endfor
  return result
 endfunction
@@ -136,10 +137,37 @@ endfunction
 " s:sort_expr must be defined as the string expression of the binary function
 " before this is called.
 " a:a and a:b are used in s:sort_expr .
+" @vimlint(EVL103, 1)
 function! s:_compare_by_string_expr(a, b) abort
  return eval(s:sort_expr)
 endfunction
+" @vimlint(EVL103, 0)
 
+" Sorts a list using a set of keys generated by mapping the values in the list
+" through the given {unary_f}.
+function! s:sort_by(list, unary_f) abort
+ let list = s:zip(a:list, s:map(copy(a:list), a:unary_f))
+ return map(sort(list, 's:_compare_with'), 'v:val[0]')
+endfunction
+
+let s:__number_pair = [type(10), type(10)]
+let s:__string_pair = [type(''), type('')]
+let s:__list_pair = [type([]), type([])]
+let s:__dict_pair = [type({}), type({})]
+let s:__function_pair = [type(function('function')), type(function('function'))]
+function! s:_compare_with(x, y) abort
+ let x = a:x[1]
+ let y = a:y[1]
+
+ let type_pair = [type(x), type(y)]
+ return type_pair ==# s:__number_pair ? s:_basic_comparator(x, y)
+ \ : type_pair ==# s:__string_pair ? s:_basic_comparator(x, y)
+ \ : type_pair ==# s:__list_pair ? s:_list_comparator(x, y)
+ \ : type_pair ==# s:__dict_pair ? 1
+ \ : type_pair ==# s:__function_pair
+ \ ? execute('throw "vital: Data.List: sort_by() cannot compare a function and a function"', 1)
+ \ : execute(printf("throw 'vital: Data.List: sort_by() cannot compare %s and %s'", string(x), string(y)), 1)
+endfunction
 
 " The basic comparator for Number and String
 function! s:_basic_comparator(x, y) abort
@@ -310,7 +338,9 @@ function! s:foldl(f, init, xs) abort
  let l:Call = s:_get_binary_caller(a:f)
  let memo = a:init
  for x in a:xs
- let memo = l:Call(a:f, [memo, x])
+ let memo_new = l:Call(a:f, [memo, x])
+ unlet memo
+ let memo = memo_new
  endfor
  return memo
 endfunction
@@ -488,8 +518,9 @@ function! s:group_by(xs, f) abort
  let l:Call = s:_get_unary_caller(a:f)
 
  for l:X in a:xs
- let key = l:Call(a:f, [l:X])
- let key = type(key) isnot type('') ? string(key) : key
+ let a_key = l:Call(a:f, [l:X])
+ let key = type(a_key) isnot type('') ? string(a_key) : a_key
+ unlet a_key
 
  if has_key(result, key)
  call add(result[key], l:X)

test/Data/List.vimspec

@@ -608,10 +608,15 @@ Describe Data.List
  End
 
  It sorts list with given the string expression
- let list = ['pineapple', 'orange', 'banana', 'apple']
-
  Assert Equals(List.sort([3, 1, 2], 'a:a - a:b'), [1, 2, 3])
- Assert Equals(List.sort(copy(list), 'len(a:a)-len(a:b)'), ['apple', 'orange', 'banana', 'pineapple'])
+ if v:version > 704 || v:version == 704 && has('patch358')
+ " sort() is stable after 7.4.358
+ let list = ['pineapple', 'orange', 'banana', 'apple']
+ Assert Equals(List.sort(copy(list), 'len(a:a)-len(a:b)'), ['apple', 'orange', 'banana', 'pineapple'])
+ else
+ let list = ['pineapple', 'banana', 'apple']
+ Assert Equals(List.sort(copy(list), 'len(a:a)-len(a:b)'), ['apple', 'banana', 'pineapple'])
+ endif
  End
 
  It sorts list with given the funcref