1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
--- Module for private utility functions
--- @alias vim.func.MemoObj { _hash: (fun(...): any), _weak: boolean?, _cache: table<any> }
--- @param argc integer?
--- @return fun(...): any
local function concat_hash(argc)
return function(...)
return table.concat({ ... }, '%%', 1, argc)
end
end
--- @param idx integer
--- @return fun(...): any
local function idx_hash(idx)
return function(...)
return select(idx, ...)
end
end
--- @param hash integer|string|fun(...): any
--- @return fun(...): any
local function resolve_hash(hash)
if type(hash) == 'number' then
hash = idx_hash(hash)
elseif type(hash) == 'string' then
local c = hash == 'concat' or hash:match('^concat%-(%d+)')
if c then
hash = concat_hash(tonumber(c))
else
error('invalid value for hash: ' .. hash)
end
end
--- @cast hash -integer
return hash
end
--- @param weak boolean?
--- @return table
local create_cache = function(weak)
return setmetatable({}, {
__mode = weak ~= false and 'kv',
})
end
--- @generic F: function
--- @param hash integer|string|fun(...): any
--- @param fn F
--- @param weak? boolean
--- @return F
return function(hash, fn, weak)
vim.validate('hash', hash, { 'number', 'string', 'function' })
vim.validate('fn', fn, 'function')
vim.validate('weak', weak, 'boolean', true)
--- @type vim.func.MemoObj
local obj = {
_cache = create_cache(weak),
_hash = resolve_hash(hash),
_weak = weak,
--- @param self vim.func.MemoObj
clear = function(self, ...)
if select('#', ...) == 0 then
self._cache = create_cache(self._weak)
return
end
local key = self._hash(...)
self._cache[key] = nil
end,
}
return setmetatable(obj, {
--- @param self vim.func.MemoObj
__call = function(self, ...)
local key = self._hash(...)
local cache = self._cache
if cache[key] == nil then
cache[key] = vim.F.pack_len(fn(...))
end
return vim.F.unpack_len(cache[key])
end,
})
end
|
