Re: Is there a similar way to do if __name__ == '__main__' as in python ?

[Rici Lake <lua@...>]

On 8-Feb-07, at 12:23 AM, Glenn Maynard wrote:

> On Wed, Feb 07, 2007 at 08:35:43PM -0800, gary ng wrote:
> > I want to write lua modules and put some self testing
> > code at the end of the script which got executed only
> > if it is run as its own and not through "require".
> >
> > In python, this is usually done through
> >
> > if __name__ = "__main__":
> >
> > How should I do it in lua ?
>
> I'm not sure (Rici probably answered that), but for this particular
> task, I'd probably do it a little differently:
>
> lua -e 'RunTests = true;' YourScript.lua
>
> and then check RunTests.

Well, in casting about for a way to simulate the Pythonic
behaviour, I did consider that, but the problem is that if
all of your modules use that system, and the target module
require()s another module, then both modules will self-test,
which may not be what you wanted (particularly if the
self-tests take a long time and/or there are a lot of
dependencies.)

So you could modify that slightly by setting
    RunTests = "modulename"
instead of just to true. However, that means hard-coding
the name of the module into the module-file, which I
wanted to avoid.

So what I was looking for was a way for a module to tell
fairly definitively whether it had been require()'d or
dofile()'d; checking the package.loaded table for a
magic undocumented sentinel may not be the most pleasant
solution, but it works. Your mileage and aesthetic sensibilities
may vary. :)