Hello,
#declare aaa = ... ;
is probably most common exprssion in POV while using it as srcipt language, 
why the idea introduced in MegaPov ( to use $aaa=...; ) was droped / not 
included into officila Pov 3.5 ?

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Rafal 'Raf256' Maj <raf### [at] raf256com> wrote:
> Hello,
> #declare aaa = ... ;
> is probably most common exprssion in POV while using it as srcipt language, 
> why the idea introduced in MegaPov ( to use $aaa=...; ) was droped / not 
> included into officila Pov 3.5 ?

  I think it had some ambiguity problems in MegaPov, IIRC. Don't remember
the details...

-- 
#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 news:Xns### [at] 204213191226 Rafal 'Raf256' Maj
wrote: 

> #declare aaa = ... ;
> is probably most common exprssion in POV while using it as srcipt
> language, why the idea introduced in MegaPov ( to use $aaa=...; ) was
> droped / not included into officila Pov 3.5 ?
> 

Not an awnser to your question, but a question triggerd by it; Why is 
there a #declare at all?

aaa="anythingyouwantittobe"

Ingo

p.s. I have no problem with #declare and think $... is unaesthetic.

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In article <Xns### [at] 204213191226>,
 "Rafal 'Raf256' Maj" <raf### [at] raf256com> wrote:

> Hello,
> #declare aaa = ... ;
> is probably most common exprssion in POV while using it as srcipt language, 
> why the idea introduced in MegaPov ( to use $aaa=...; ) was droped / not 
> included into officila Pov 3.5 ?

1: It's ugly.
2: It's harder to read.
3: It doesn't fit in with the rest of the syntax.
4: It didn't work right. I don't know what exactly the problems were (I 
never used the patch), but there were problems with it.

I don't like the current syntax either, though...take this code for 
example:

#declare myCounter = 0;
#while(myCounter < 10)
    Code
    Code
    Code
    Code
    ...
    #declare myCountr = myCounter + 1;
#end

That's an infinite loop from a simple typo, because POV doesn't know the 
difference between modifying a variable and making a new one.

I made a patch that allowed this:
#declare myCounter = 0;
#while(myCounter < 10)
    #set myCountr = myCounter + 1;
#end

#set will modify a variable, but it will give an error if it doesn't 
already exist, something like "attempt to set nonexistant variable". It 
is also less typing, and makes less code to modify if you decide to put 
things in a macro...it works with local variables just fine, so you have 
fewer #declares to turn into #locals.

This was designed to fit in with the current syntax, though. I'd rather 
redesign the language and use something more like:

def myCounter = 0;
while(myCounter < 10) {
    myCounter += 1;
}

-- 
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:


> redesign the language and use something more like:
> 
> def myCounter = 0;
> while(myCounter < 10) {
>     myCounter += 1;
> }

Having +=, -=, etc... would certainly be nice.  Even with #declare, if 
it issued and error for uninitialized variables, for example:

#declare myCounter = 0;
#while( myCounter < 10 ) {
     #declare myCountr += 1;
}

The parser could choke and issue an error because it doesn't know what 
the initial value of "myCountr" is.

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   videotron.ca  */}camera{orthographic location<6,1.25,-6>look_at a }

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Another good thing about the operator-and-assignment is that it can
save writing and make parsing faster.
  For example, consider this:

#declare Table[Index1*2+Offset1][Index2*2+Offset2] =
Table[Index1*2+Offset1][Index2*2+Offset2] + 1;

vs:

#declare Table[Index1*2+Offset1][Index2*2+Offset2] += 1;

-- 
#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 <war### [at] tagpovrayorg> wrote in news:3db1b7e0@news.povray.org

#declare Table[Index1*2+Offset1][Index2*2+Offset2] =
Table[Index1*2+Offset1][Index2*2+Offset2] + 1; 

$Table[$Index1*2+$Offset1][$Index2*2+$Offset2]+=1;

syntax $var_name ihas one greate advantage :

$sphere = 10;
$ior = 50;

You can use variable names that are reserved words. This is in fact VERY usefull,
in stuff like :

// from #version 3.1
#declare dispersion = 5.0;  

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Rafal 'Raf256' Maj <raf### [at] raf256com> wrote:
> syntax $var_name ihas one greate advantage :

> $sphere = 10;
> $ior = 50;

> You can use variable names that are reserved words.

  How do you expect to use those variable names?

-- 
#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 <war### [at] tagpovrayorg> wrote in news:3db1bd8f$6@news.povray.org

I.e someone will write script, with variables like say :
  a, b, c, speed, displacment, size
It will work fine, until in say POV 4.0 displacment will became a 
reserved word and stop this script from working.

I like very much PHP style - where every variable name starts with '$'.

What do You think about allowing, as PHP, syntax with variant types, 
say :
$x = 100;
  "foo"+$x+"bar"  will result in "foo100bar" (x is used like string)
and :
  20 + $x         will result in 120 (x is used like number)

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Rafal 'Raf256' Maj wrote:

> I.e someone will write script, with variables like say :
>   a, b, c, speed, displacment, size
> It will work fine, until in say POV 4.0 displacment will became a
> reserved word and stop this script from working.

Just do as the docs suggest and use at least one capital letter in your 
variable names.

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