POV-Ray : Newsgroups : povray.bugreports : bump maps inverted in spherical warp : Re: bump maps inverted in spherical warp Server Time
20 Oct 2021 16:04:17 EDT (-0400)
  Re: bump maps inverted in spherical warp  
From: Thorsten
Date: 5 Aug 2021 05:42:34
Message: <610bb28a$1@news.povray.org>
On 05.08.2021 09:28, Kenneth wrote:
> "pkoning" <nomail@nomail> wrote:
>>
>> ...the parser complains that the "warp" modifier is not expected.  See
>> attached.
>>
>> Possible Parse Error: Unmatched {
>> ...
>> Parse Error: No matching }, warp found instead
> 
> By the way: As Clipka pointed out in a another recent thread, those "unmatched
> {" warnings/errors are sometimes 'generic', in that they simply flag some kind
> of 'possible' error that isn't clearly known to the parser. Yeah, it's kind of
> confusing sometimes, to figure out what the true problem is. ;-)

Actually, the reason this is called "possible error" (my naming back 
then) has to do with the message driven changes to output from POV-Ray 
3.5 onward. Before, the parser would simply output to a text stream, so 
it was perfectly feasible to output some text somewhere and the next 
line would make sense out of it (from the user's perspective). However, 
there might be a long and complex call chain of internal parser 
functions between the place that detected the likely error and the place 
that actually knows it is an error.

In modern integrated development environments (IDEs) it is at last 
handled much better because the parsers hand them a full trace of all 
the steps they took to get where they are and the user gets a kind of 
trace where the parser went with each step and what it expected or 
allowed. So yes, error reporting evolved over the last 15 years. But it 
would require a very well structured parser, which POV-Ray doesn't have 
due to its age (and no, it is not easy to rewrite either, nor is it a 
beginner's task).

Thorsten


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