Re: do you use the pre-processor?
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- Subject: Re: do you use the pre-processor?
- From: Roberto Ierusalimschy <roberto@...>
- Date: 2000年5月26日 11:18:31 -0300
On 2000年5月12日, Dave Gordon wrote:
> |
> | How about starting it with "comment = [[" and ending with "]]". That's
> | what I usually do...
>
> That's a good idea, but it doesn't work well in some cases. At least
> I don't see a way to make it work in a situation I encounter often
> while debugging my renderer. I use $if, $end to comment out sections
> of large data arrays (vertex and polygon lists to be precise) to try
> to locate regions of the data were a problem is occuring. For that
> purpose "comment = [[...]]" doesn't work because (I believe) there's
> no valid syntax that allows it to be put it in the middle of table
> constructor consisting of a list of objects. So unless there's
> another trick I'm missing I still think a block comment delimiter
> would be helpful. That is in the absence of $if, $end of course.
There is a valid syntax for this case (a dirty trick, in fact)! If you
have a constructor like
a = { 1.0, 2.0, 3.0, 4.0, 5.0 }
you can remove part of it with
a = { 1.0, [[2.0, 3.0, 4.0,]] and 5.0 }
A string is always true, so this `and' results in its second operand. It
does not work only when you want ro remove a sufix of the constructor.
-- Roberto