const

  buckets = 20;

type

  domain = char;
  range  = integer;

  mapcell = record
            d : domain;
            r : range;
            end;

  listelement = mapcell;

  listlink = ^listcell;

  listcell = record
    left : listlink;
    right : listlink;
    element : mapcell;
  end;

  list = ^listcell;

  listposition = listlink;    

  bucket = list;

  map = array[0..buckets] of bucket;


function maphash(d : domain):integer;
{+--- on entry - d exists and is a single character
 |    on exit  - maphash contains a number between 1 and maphashbuckets
 +-----------------------------------------------------------------------}

begin
maphash := ord(d) mod buckets;
end;


function compare(e1,e2 : listelement):integer;
{+--- on entry - e1 and e2 are transfered in for a comparison
 |    on exit  - compare returns +1 iff e1 > e2
 |                                0 iff e1 = e2
 |                               -1 iff e1 < e2
 +----------------------------------------------------------------------}

begin {compare}
if e1.d > e2.d then compare := 1
           else if e1.d < e2.d then compare := -1
                           else compare := 0;
end; {compare}


procedure print(var out:text; e:listelement);
{+--- on entry - e is contained in the list and is ready for output
 |    on exit  - e has been written to the corresponding out file
 +------------------------------------------------------------------------}

begin {print}
writeln (out,e.d:4,'   'e.r:4);
end; {print}


.