Extending assert () functionality
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Extending assert () functionality
- From: Rebel Neurofog <rebelneurofog@...>
- Date: 2011年6月25日 22:52:32 +0400
Hi!
I've been thinking about dealing with 'assert ()' in case of complex
error message evaluation.
Say, we have something like this:
local function complex_call (a)
if (math.sin (a*3 + 0.3) < 0.5) then
return "Got no idea"
else
return "Damn, I don't know"
end
end
assert (1 == 3, "Reactor response failure: "..complex_call (13))
It is known that error message is evaluated even if assertion succeeds.
It could be easy to replace it with lazy evaluation like this:
assert (1 == 3, function () return "Reactor response failure:
"..complex_call (13) end)
if assert () would accept both error message and error message
generating function.
So I suggest a patch like this for Lua 5.2.x and Lua 5.1.5:
@@ -333,8 +333,15 @@ static int luaB_dofile (lua_State *L) {
static int luaB_assert (lua_State *L) {
luaL_checkany(L, 1);
- if (!lua_toboolean(L, 1))
+ if (!lua_toboolean(L, 1)) {
+ if (lua_isfunction(L, 2)) {
+ lua_checkstack(L, 1);
+ lua_pushvalue(L, 2);
+ lua_call(L, 0, 1);
+ lua_replace(L, 2);
+ }
return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion
failed!"));
+ }
return lua_gettop(L);
}
As an alternative additional version of assert () could be added.