%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/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

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

/c.isdigit {
    dup 48 ge exch 57 le and
} 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

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


% end included library code

/formatphonenumber {
    0 dict begin
    s2a { c.isdigit } filter /pure exch def
    /left pure length def
    /i 0 def
    [
        left 4 gt {
            pure {
                /i i 1 add def
                /left left 1 sub def
                i 3 mod 0 eq {
                    45
                    left 4 le {
                        exit
                    } if
                } if
            } forall
        } if
        left 4 eq {
            pure i get
            pure i 1 add get
            45
            /i i 2 add def
        } if
        i 1 pure length 1 sub {
            pure exch get
        } for
    ] a2s
    end
} bind def

(formatphonenumber) test.start
(1-23-45-6) formatphonenumber (123-456) eq test
(1234) formatphonenumber (12-34) eq test
(12 345-6789) formatphonenumber (123-456-789) eq test
(123 4567) formatphonenumber (123-45-67) eq test
(123 456-78) formatphonenumber (123-456-78) eq test
test.end