%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/dget {
    3 1 roll
    2 copy
    known {
        get exch pop
    } {
        pop pop
    } ifelse
} 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

/values { % dict -> array of dict values
    [ exch
      {
          exch pop
      } forall
    ]
} bind def

/reduce { % array proc -> value
    2 dict begin
    /p exch def
    /a exch def
    a 0 get
    1 1 a length 1 sub {
        a exch get
        p
    } for
    end
} bind def

/filter { % array proc(bool) -> array
    1 dict begin
    /p exch def
    [ exch
      {
          dup p not
          {
              pop
          } if
      } forall
    ]
    end
} bind def

/keys { % dict -> array of dict keys
    [ exch
      {
          pop
      } forall
    ]
} bind def

/s2a {
    [ exch { } forall ]
} bind def

/a2s {
    2 dict begin
    /i exch def
    i length dup string /o exch def
    1 sub 0 exch 1 exch {
        dup i 3 -1 roll get o 3 1 roll put
    } for
    o
    end
} bind def

/listmax {
    { max } reduce
} 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

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


% end included library code

/isalpha {
    dup
    dup 65 ge exch 90 le and exch
    dup 97 ge exch 122 le and or
} bind def

/splitalpha {
    0 dict begin
    s2a /s exch def
    /state false def
    [
        /x -1 def
        0 1 s length 1 sub {
            /i exch def
            s i get isalpha {
                state not {
                    /x i def
                } if
                /state true def
            } {
                state {
                    [ x i ]
                } if
                /state false def
            } ifelse
        } for
        state {
            [ x i ]
        } if
    ]
    [ exch {
          aload pop
          1 index exch sub neg
          s 3 1 roll
          getinterval a2s
      } forall
    ]
    end
} bind def

/mostfrequentword {
    0 dict begin
    exch
    /words 0 dict def
    splitalpha {
        /c exch def
        words c 0 dget 1 add words exch c exch put
    } forall
    words exch undef
    /m words values listmax def
    /k words keys { words exch get m eq } filter def
    k 0 get
    end
} bind def

(mostfrequentword) test.start
(Joe hit a ball, the hit ball flew far after it was hit.) (hit) mostfrequentword (ball) eq test
(Perl and Raku belong to the same family. Perl is the most popular language in the weekly challenge.) (the) mostfrequentword (Perl) eq test
test.end