Re: Bug: \textext inside \*MPinclusions causes error

[Hans Hagen <pragma@wxs.nl>]

On 1/16/2017 8:31 PM, Sergey Slyusarev wrote:
>> the (subtle) difference between the two [*MPinclusions and */MPinitializations/] is not a bug but a feature
>
> If I understood correctly, *MPinitializations affects everything and can't be assigned to a specific instance (or can it?),
> in some cases (like mine) this difference is not so subtle.
>
> Look at the following example (not so minimal):
>
> \startMPinitializations
>
> picture p;
>
> p := image(
>
> draw fullsquare scaled 1cm;
>
> draw textext("1");
>
> );
>
> \stopMPinitializations
>
> \startMPinitializations
>
> picture s;
>
> s := image(
>
> draw (fullsquare rotated 45) scaled 1cm;
>
> draw textext("2");
>
> );
>
> \stopMPinitializations
>
> \defineMPinstance[foo][initializations=yes]
>
> \startMPcode{foo}
>
> picture q;
>
> q := image(
>
> draw fullcircle scaled 1cm;
>
> draw textext("3");
>
> );
>
> draw q;
>
> \stopMPcode
>
> \startMPcode{foo}
>
> draw p;
>
> draw q shifted (2cm, 0);
>
> draw s shifted (4cm, 0);
>
> \stopMPcode
>
> \defineMPinstance[bar][initializations=yes]
>
> \startMPcode{bar}
>
> picture r;
>
> r := image(
>
> draw fullcircle scaled 1cm;
>
> draw textext("4");
>
> );
>
> draw r;
>
> \stopMPcode
>
> \startMPcode{bar}
>
> draw p;
>
> draw r shifted (2cm, 0);
>
> draw s shifted (4cm, 0);
>
> \stopMPcode
>
>
> First, it shows why *MPinitializations can't replace *MPinclusions for
> me (it affects all instances),
>
> and second, it silently produces produces some really unexpected results:
>
> It looks like it should produce (by line)
>
> A circle with "3" inside (yes)
>
> A square with "1" inside (yes); A circle with "3" inside again (no,
> instead it produces circle with "2" inside); A rhombus with "2" inside
> (no, instead it produces a rhombus with "1")
>
> and so on.
>
> (tested on http://live.contextgarden.net/)
>
> In fact, I failed to declare picture variable inside with text inside
> one *MPcode environment and pass it to another safely
>
> (text either disappears or changes to other text, and this time ConTeXt
> returns no error), that surely is a bug?

no, it's the way it works ... but keep in mind that textexts are 
something bound to a specific code snippet so you can bets do something 
like this:

\starttext

\defineMPinstance[foo][definitions=yes]
\defineMPinstance[bar][definitions=yes]

\startMPdefinitions{foo}
     vardef p =
         image(
             draw fullsquare scaled 1cm;
             draw textext("1");
         )
     enddef ;
\stopMPdefinitions

\startMPdefinitions{bar}
     vardef p =
         image(
             draw (fullsquare rotated 45) scaled 1cm;
             draw textext("2");
         )
     enddef;
\stopMPdefinitions

\startMPcode{foo}
     draw p;
     draw image(
         draw fullcircle scaled 1cm;
         draw textext("3");
     );
     draw p;
\stopMPcode

\startMPcode{bar}
     draw p;
     draw image(
         draw fullcircle scaled 1cm;
         draw textext("4");
     );
\stopMPcode

\stoptext



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                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
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