%!PS

% begin library code

/strconcat % (a) (b) -> (ab)  
{ exch dup length
  2 index length add string
  dup dup 4 2 roll copy length
  4 -1 roll putinterval
} bind def

/strjoin % [(a) (b) (c)] (j) -> (ajbjc)
{
    3 dict begin
    /j exch def
    dup 0 get /out exch def
    /first true def
    {
        first {
            /first false def
        } {
            out j strconcat
            exch strconcat
            /out exch def
        } ifelse
    } forall
    out
    end
} def

/apush { % [a b] c -> [a b c]
    exch
    [ exch aload length 2 add -1 roll ]
} bind def

/deepeq {
    2 dict begin
    /a exch def
    /b exch def
    a type b type eq {
        a type /dicttype eq {
            a length b length eq {
                <<
                    a {
                        pop
                        true
                    } forall
                    b {
                        pop
                        true
                    } forall
                >>
                true exch
                {
                    pop
                    dup a exch known {
                        dup b exch known {
                            dup a exch get exch b exch get deepeq not {
                                pop false
                            } if
                        } {
                            false
                        } ifelse
                    } {
                        false
                    } ifelse
                } forall
            } {
                false
            } ifelse
        } {
            a type dup /arraytype eq exch /stringtype eq or {
                a length b length eq {
                    true
                    0 1 a length 1 sub {
                        dup a exch get exch b exch get deepeq not {
                            pop false
                            exit
                        } if
                    } for
                } {
                    false
                } ifelse
            } {
                a b eq
            } ifelse
        } ifelse
    } {
        false
    } ifelse
    end
} bind def

/test {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def

/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} bind def

/test.end {
    ( ) print
    test.count 0 gt {
        (Passed ) print
        test.pass (...) cvs print
        (/) print
        test.count (...) cvs print
        ( \() print
        test.pass 100 mul test.count idiv (...) cvs print
        (%\)) print
        (\r\n) print
    } if
} bind def

% end library code

/fid {
    3 dict begin
    /words [ (zero) (one) (two) (three) (four)
             (five) (six) (seven) (eight) (nine) ] def
    /p 0 array def
        {
            dup
            words exch get ( is ) strconcat /s exch def
            dup 4 eq {
                pop
                /s s (magic.) strconcat def
                /p p s apush def
                exit
            } {
                words exch get length
                dup words exch get s exch strconcat /s exch def
                /p p s apush def
            } ifelse
        } loop
    p (, ) strjoin
    dup 0 get 32 sub exch dup 3 -1 roll 0 exch put
    end
} bind def

(fid) test.start

5 fid
(Five is four, four is magic.)
deepeq test

7 fid
(Seven is five, five is four, four is magic.)
deepeq test

6 fid
(Six is three, three is five, five is four, four is magic.)
deepeq test

4 fid
(Four is magic.)
deepeq test

test.end