-- The package FUNDAMENTALS defines a type OFFSET for offset pairs
-- and a type SYMBOL_TYPE to contain both a string reprsenting a
-- symbol and its length.  It also defines pointers to both types.
-- An equality operator is defined for SYMBOL_TYPES and several
-- operations are defined for OFFSETs.
-- Also, the package declares a global symbol TOKEN

package fundamentals is

CONST_FLAG: constant integer:= 99;
LIST_SIZE: constant integer:= 20;
TOKEN_SIZE: constant integer:= 20;
ERROR_FLAG: constant integer:= -1;    -- assume this is an illegal value


type symbol_type is record
  name:string(1..TOKEN_SIZE);
  length:integer;
end record;

type symbol_type_ptr is access symbol_type;

token:symbol_type_ptr:=new symbol_type;


-- Return TRUE iff two symbols are equal
function equal(s,t:symbol_type_ptr) return BOOLEAN;


----------------------- the type OFFSET -------------------------------

type offset is record
  first:integer;
  second:integer;
end record;

type offset_ptr is access offset;

------  The three functions below operate on offset pairs as follows:
-- Return the first element of an offset pair, given a pointer to the pair
-- Return the second element of an offset pair, given a pointer to the pair
-- Print both elements of an offset pair

function get_first(o:offset_ptr) return integer;
function get_second(o:offset_ptr) return integer;
procedure print_offset(o:offset_ptr);

end fundamentals;