PostScript 条件分岐

% ---variables---------------------------------------------
/LM 72 def
/RM 212 3 mul def
/ypos 720 def
/lineheight 40 def
% ---procedures--------------------------------------------
/newline{
    ypos lineheight sub
    /ypos exch def
    LM ypos moveto
} def
/prtstr{
    dup stringwidth pop
    currentpoint pop
    add RM gt
    {newline} if
    show
} def
/choosefont{
    exch findfont exch scalefont setfont
} def
% ---main program------------------------------------------
/Times-Italic findfont 50 scalefont setfont
LM ypos moveto
(If ) prtstr
(you ) prtstr
(tell ) prtstr
(the ) prtstr
(truth, ) prtstr
(you ) prtstr
(don't ) prtstr
(have ) prtstr
(to ) prtstr
(remember ) prtstr
(anything. ) prtstr
(- Mark ) prtstr
(Twain ) prtstr
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% --- variables ----------------------------------------
/scalefactor 1 def
/counter 0 def
% --- procedures ---------------------------------------
/DecreaseScale {
    scalefactor .2 sub
    /scalefactor exch def
} def
/IncreaseConter {
    /counter counter 1 add def
} def
/trappath {
    0 0 moveto
    90 0 rlineto
    -20 45 rlineto
    -50 0 rlineto
    closepath
} def
/doATrap {
    gsave
    1 scalefactor scale
    trappath
    counter 2 mod
    0 eq {.5} {0} ifelse
    setgray fill
    grestore
} def
% --- programs -----------------------------------------
0 0 moveto
250 350 translate
10 {
    IncreaseConter
    doATrap
    DecreaseScale
    0 20 translate
} repeat
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• eq =
• ne ≠
• gt >
• lt <
• ge >=
• le <=

• P.62 - 7.1 CONDITIONAL EXECUTION
• PostScript - PDF,Web まとめ