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author | Pavel Labath <pavelo@centrum.sk> | 2011-05-16 10:58:21 (GMT) |
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committer | Paul Tagliamonte <paultag@fluxbox.org> | 2012-04-07 02:08:41 (GMT) |
commit | 0fa62fe1598c5b04925c0b7b98d0d00d28d10d88 (patch) | |
tree | ccc2dd040a03b294b17abaa4da55ca00ed9b82a7 /libs/lua/etc/strict.lua | |
parent | 7b6dc2ad72a4c4ecd20eddbfb6f1b4c3bd2a7024 (diff) | |
download | fluxbox_paul-0fa62fe1598c5b04925c0b7b98d0d00d28d10d88.zip fluxbox_paul-0fa62fe1598c5b04925c0b7b98d0d00d28d10d88.tar.bz2 |
Add lua as an internal library in libs/lua
Diffstat (limited to 'libs/lua/etc/strict.lua')
-rw-r--r-- | libs/lua/etc/strict.lua | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/libs/lua/etc/strict.lua b/libs/lua/etc/strict.lua new file mode 100644 index 0000000..604619d --- /dev/null +++ b/libs/lua/etc/strict.lua | |||
@@ -0,0 +1,41 @@ | |||
1 | -- | ||
2 | -- strict.lua | ||
3 | -- checks uses of undeclared global variables | ||
4 | -- All global variables must be 'declared' through a regular assignment | ||
5 | -- (even assigning nil will do) in a main chunk before being used | ||
6 | -- anywhere or assigned to inside a function. | ||
7 | -- | ||
8 | |||
9 | local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget | ||
10 | |||
11 | local mt = getmetatable(_G) | ||
12 | if mt == nil then | ||
13 | mt = {} | ||
14 | setmetatable(_G, mt) | ||
15 | end | ||
16 | |||
17 | mt.__declared = {} | ||
18 | |||
19 | local function what () | ||
20 | local d = getinfo(3, "S") | ||
21 | return d and d.what or "C" | ||
22 | end | ||
23 | |||
24 | mt.__newindex = function (t, n, v) | ||
25 | if not mt.__declared[n] then | ||
26 | local w = what() | ||
27 | if w ~= "main" and w ~= "C" then | ||
28 | error("assign to undeclared variable '"..n.."'", 2) | ||
29 | end | ||
30 | mt.__declared[n] = true | ||
31 | end | ||
32 | rawset(t, n, v) | ||
33 | end | ||
34 | |||
35 | mt.__index = function (t, n) | ||
36 | if not mt.__declared[n] and what() ~= "C" then | ||
37 | error("variable '"..n.."' is not declared", 2) | ||
38 | end | ||
39 | return rawget(t, n) | ||
40 | end | ||
41 | |||