In article <3f5f4f76$1@news.povray.org> , Florian Brucker 
<tor### [at] torfboldcom>  wrote:

> I understand this from the parser's point of view - normaly, opening
> brackets inside #ifndef() do not make sense, as identifiers aren't
> allowed to contain brackets. In the case of Parse_String(), however,
> it makes sense.

This isn't the parsers problem, it is your scene.  You simply do not
generate a valid scene with what you do.  This should be clear from the
specification of #ifndef (taking only a single identifier).

However, this isn't all.  There is a second misconception.  What you expect
is #macros to behave like macros, not functions.  However, if you read the
chapter in the documentation which explains the difference between the
POV-Ray #macro and what most people commonly expect from macros (and how
macros return something), you will notice that what you do cannot work as
expected.

Even worse, there is a third roadblock in your code, which is that a #macro
name can also be checked with an #ifndef.  And actually this is what the
parser catches first and reports an error for.  nevertheless, the first two
problems would persist even if this would be accepted by the parser.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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It would be nice if the string parsing was an internal command which
could be used anywhere.
  I suppose #parse would be a good name. This way you could do things like:

#declare #parse(concat(name1, name2)) = 5;

  That is, the parser would take the string given as parameter to #parse
and parse its contents as if it was just plain text appearing at that place
in the file. This would certainly be handy for many things.

  (OTOH it accentuates the importance of I/O restrictions because it would
allow making extremely obfuscated SDL code.)

  I think one important feature of this #parse command that differentiates
it from other commands is that it should be possible to appear *anywhere*
in the code. Even though this is not strictly indispensable, it would
certainly make it more useful.
  That is for example this:

#de#parse("cl")are ab#parse("cde")fg = 5;

would be effectively the same thing as:

#declare abcdefg = 5;

  I don't know if this behaviour would be easy to implement in the current
parser, but just an idea...

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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In article <3f5f6336@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:

>   That is for example this:
>
> #de#parse("cl")are ab#parse("cde")fg = 5;
>
> would be effectively the same thing as:
>
> #declare abcdefg = 5;
>
>   I don't know if this behaviour would be easy to implement in the current
> parser, but just an idea...

Aren't *you* the one who usually argues for well structured code? ;-) ;-)

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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Thorsten Froehlich <tho### [at] trfde> wrote:
> Aren't *you* the one who usually argues for well structured code? ;-) ;-)

  In C++ yes, but the POV-Ray SDL is a hacker language. :P

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -

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Warp wrote:
> Thorsten Froehlich <tho### [at] trfde> wrote:
> 
>>Aren't *you* the one who usually argues for well structured code? ;-) ;-)
> 
> 
>   In C++ yes, but the POV-Ray SDL is a hacker language. :P
> 
Do you mean a language for 'hacks', or a language for 'hackers'?

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Jim Charter <jrc### [at] msncom> wrote:
> >   In C++ yes, but the POV-Ray SDL is a hacker language. :P
> > 
> Do you mean a language for 'hacks', or a language for 'hackers'?

  Mainly I meant a language for hackers. You know, that type of language
which you can use to make marvelous things with an incredibly short piece
of code... which is also so obfuscated you don't understand it at all... :P

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -

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> Thanks Tim!
>
> Greetings,
> Florian

You're welcome. I figured this one pretty
fast because I had similiar ideas about dynamic
texture/array/object generation some months
ago, and gave thought to those issues at
that time. And seeing your code, it was
rather simple to just write my initial thoughts
about it... :-)

-- 
Tim Nikias v2.0
Homepage: http://www.digitaltwilight.de/no_lights
Email: no_lights (@) digitaltwilight.de


> Hi Tim!
>
> > You've got to experiment. Perhaps writing the entire
> > #ifndef () ... #debug ".." #end
> > to disc and #including that.
> That did the job!
>
> if anyone is interested, here's the code:
>
> <code>
> #include "strings.inc"
>
> #declare TestIdent = 1;
>
> #macro IFDEF2(Name)
> #declare TEMPDEF__ = 0;
>
> Parse_String(concat(
> "#ifdef(",Name,")
> #declare TEMPDEF__=1;
> #end"
> ))
>
> (TEMPDEF__)
> #end
>
> #if (IFDEF2("TestIdent"))
> #debug "defined\n"
> #else
> #debug "nope\n"
> #end
> </code>
>
> result: defined
>
> Thanks Tim!
>
> Greetings,
> Florian
> -- 
> //=================[web: http://www.torfbold.com]==================\\
> #local a=-5;#while(a<5)sphere{<sin(a*pi)*5a*10pow(a,5)*.01>sin(a*a*a*
> .1)+1pigment{rgb 9*z}}#local a=a+.01;#end camera{look_at-y*10location
> <8,-3,-8>*10}// [www.povray.org]     [www.imp.org]     [www.irtc.org]
>


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In article <3f5f6476@news.povray.org>,
 "Thorsten Froehlich" <tho### [at] trfde> wrote:

> In article <3f5f6336@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:
> 
> > #de#parse("cl")are ab#parse("cde")fg = 5;
> 
> Aren't *you* the one who usually argues for well structured code? ;-) ;-)

Aren't you forgetting who started the scrambled signature craze?

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> 
> In article <3f5f6476@news.povray.org>,
>  "Thorsten Froehlich" <tho### [at] trfde> wrote:
> 
> > In article <3f5f6336@news.povray.org> , Warp <war### [at] tagpovrayorg>  wrote:
> >
> > > #de#parse("cl")are ab#parse("cde")fg = 5;
> >
> > Aren't *you* the one who usually argues for well structured code? ;-) ;-)
> 
> Aren't you forgetting who started the scrambled signature craze?

I haven't (in case he conveniently forgets) and would be more than
happy to name names.

-- 
Ken Tyler

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Ken <tyl### [at] pacbellnet> wrote:
> > Aren't you forgetting who started the scrambled signature craze?

> I haven't (in case he conveniently forgets) and would be more than
> happy to name names.

  But I'm proud of that. :)

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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