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
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
--- Stricter version of compat52.
-- Attempts to emulate Lua 5.2 when built without LUA_COMPAT_ALL.
if _VERSION == "Lua 5.1" then
require("compat52")
local function not_available()
error("This function is not available in Lua 5.2!", 2)
end
local exclude_from_G = {
module = not_available,
getfenv = not_available,
setfenv = not_available,
loadstring = not_available,
unpack = not_available,
loadlib = not_available,
math = {
log10 = not_available,
mod = not_available,
},
table = {
getn = not_available,
setn = not_available,
},
string = {
gfind = not_available,
},
}
local next = next
local function make_pairs_iterator(lookup)
return function(st, var)
local k, v = next(st, var)
if k ~= nil then
local new_v = lookup[k]
if new_v ~= nil then v = new_v end
return k, v
end
end
end
local rawget = rawget
local function make_ipairs_iterator(lookup)
return function(st, var)
var = var + 1
local v = rawget(st, var)
if v ~= nil then
local new_v = lookup[var]
if new_v ~= nil then v = new_v end
return var, v
end
end
end
local function make_copy(value, excl)
local v_type, e_type = type(value), type(excl)
if v_type == e_type then
if v_type == "table" then
local l_table = {}
for k, v in pairs(excl) do
l_table[k] = make_copy(rawget(value, k), v)
end
local pairs_iterator = make_pairs_iterator(l_table)
local ipairs_iterator = make_ipairs_iterator(l_table)
return setmetatable({}, {
__index = function(_, k)
local v = l_table[k]
if v ~= nil then
return v
else
return value[k]
end
end,
__newindex = function(_, k, v)
if l_table[k] ~= nil then
l_table[k] = nil
end
value[k] = v
end,
__pairs = function()
return pairs_iterator, value, nil
end,
__ipairs = function()
return ipairs_iterator, value, 0
end,
}), l_table
elseif v_type == "function" then
return excl
end
end
end
local new_G, G_lookup = make_copy(_G, exclude_from_G)
G_lookup._G = new_G
return function()
setfenv(2, new_G)
end
else
return function() end
end
-- vi: set expandtab softtabstop=3 shiftwidth=3 :
|
