Re: Clean Lua

[Miles Bader <miles@...>]

David Manura <dm.lua@math2.org> writes:
>>> local env; env = setmetatable({
>>>   import = function(name, value) env[name] = value end
>>> }, {__index = _G})
>>
>> Hmmm, that would work, but would require one to keep tight control on
>> file loading [...]
>
> It can even be preferable.  Consider for instance trying to pass
> `import` as a callback function like `pcall(import, ...)`.  Your
> original code probably would fail there because it would attempt to
> write into the C environment of `pcall`.

Sure, that's a problem with the 5.1 version.  I'd consider acceptable
in this case to say "so don't do that!", but your implementation might
also be a good way to avoid such problems.

However, I'm more interested in what people think of the tradeoff
between the two suggested forms in 5.2:

    import (_ENV, "blah", ...)

vs.

    import ("blah", ...)
    with "magic" setting of the environment by the file-loading machinery

Is slight "ugliness" of the former justified by the additional clarity
of being explicit and possibly a bit more robust/flexible?

-Miles

-- 
Absurdity, n. A statement or belief manifestly inconsistent with one's own
opinion.