dadaprolog.ps

%!PS
%%Creator: acb
%%CreationDate: July 11, 1995

%% This is code for resolving recursive grammars in PostScript.
%% This code is part of the Dada Engine and copyright of Andrew C. Bulhak
%% You may use, distribute and modify this code in any way provided that
%% this copyright notice remains intact.

/bd {bind def} bind def

% choose an element from an array at random
% syntax: [array] choose elem

/choose {
  dup length rand exch mod get
} bd

% concatenate an array of strings into a string
% [array] strcat (str)
/strcat {
  dup 
} bd

% syntax: name value conddef -

/conddef {
  1 index where { pop pop pop } { def } ifelse
} bd

% (str) n repeat [array]

/rep {
  dup 1 1 3 -1 roll {
    pop exch dup 3 -1 roll
  } for
  [ exch 1 add 1 roll ] exch pop
} bd

% syntax: string star [strings]

/star {
  0 { rand 5 mod 1 le {exit} if 1 add } loop
  rep
%  dup array exch 1 1 3 -1 roll
%  { 1 sub 1 index exch 3 index put } for
%  exch pop
} bd

/plus {
  1 { rand 5 mod 1 le {exit} if 1 add } loop
  rep
%  dup array exch 1 1 3 -1 roll
%  { 1 sub 1 index exch 3 index put } for
%  exch pop
} bd

%% End of Dada Engine prologue