[metapost] accessing letters in picture (for...within loop)

[Taco Hoekwater]

Hi,

Stephan Hennig wrote:
> want to access the coordinates of single letters.  Is there any way to
> tell MetaPost to process pictures letter by letter?

With a "Thank you!" to Hans for a behind-the-scenes answer:

   string s;
   for i=0 upto length(t)-1:
     s := substring(i,i+1) of t ;
     show s;
   endfor;

Greetings, Taco