🚀 go-pugleaf

From: Brian Reid <reid@Glacier>

Not being a TEX user myself, I'm not ready to jump in and fix this
problem, but those of you who are working on complicated
font-space-management PostScript software might want to study carefully
the following example, and remember that the bitmaps in bitmap fonts
are stored in strings, and remember further that the "getinterval"
operator will construct a new string descriptor pointing to a piece of
existing string body. This will allow you to construct a large buffer in
string space, whose contents will not be changed by save/restore, and
which can be managed using an allocate/free protocol like any other
buffer pool. 

%!
% PostScript program to show an obscure semantic property of strings in
% the presence of save/restore. See the looseleaf (first edition) PS
% manual, page 94, section 3.4.11 (Virtual Memory Operators), second
% paragraph, lines 5 and 6.

/ss (Prunes taste wonderful) def	% define two sample strings
/dd (Oranges are sour.) def
dd					% push dd body on the stack
/saveobj save def			% save the world
/ss (Prunes are awful) def		% redefine ss
/dd (Oranges are lemons) def		% redefine dd
  0 (Oranges are sweet) putinterval 	% use stacked dd body
saveobj restore				% restore the world
/Courier findfont 10 scalefont setfont	% print the answers
100 600 moveto ss show
100 588 moveto dd show
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