with Text_IO; use Text_io;
package body INTEGER_SETS is  -- array INTEGER of BOOLEAN
  package IIO is new Text_IO.Integer_io(integer); --need integer output
  use iio;
    N:constant integer:=500;
    subtype ELEMENT is INTEGER range 1..N;
    type DATA is array(ELEMENT) of boolean; -- INTEGER_SET is access DATA
    ALL_FALSE:constant DATA:=DATA'(1..N=>false);


  function  Member(I:INTEGER; ISIN:INTEGER_SET) return boolean is
  begin return ISIN.all(I);
  exception when CONSTRAINT_ERROR => return FALSE; -- ISIN=NULL
			--or I is outside range.
  end Member;


  function  Empty(ISIN:INTEGER_SET) return boolean is --Empty(NULL_SET);
  begin --return ISIN.all/=all_false;
	for i in ISIN.all'range loop
		if ISIN.all(I) then return false;
		end if;
	end loop;
	return true;
  exception when CONSTRAINT_ERROR => return TRUE; -- ISIN=NULL
  end Empty;

  function  "="(LEFT,RIGHT:INTEGER_SET) return boolean is
	EL:BOOLEAN:=Empty(LEFT);
	ER:BOOLEAN:=Empty(RIGHT);
  begin if EL or ER then return EL and ER;
	else return LEFT.all=RIGHT.all;
	end if;
  end "=";

  function  Full(ISIN:INTEGER_SET) return boolean is
  begin return FALSE;
  end Full;

  procedure Make_Empty(S:out INTEGER_SET) is -- after S=NULL_SET
  begin S:=NULL;
  end;

  function  Max(S:INTEGER_SET) return integer is
  begin for i in reverse S.all'range loop
		if S.all(I) then return I;
		end if;
	end loop;
	raise EMPTY_GET;
  exception when CONSTRAINT_ERROR => raise EMPTY_GET;
  end Max;

  function  Min (S:INTEGER_SET) return integer is
  begin for i in S.all'range loop
		if S.all(I) then return I;
		end if;
	end loop;
	raise EMPTY_GET;
  exception when CONSTRAINT_ERROR => raise EMPTY_GET;
  end Min;


  procedure Put(S:in INTEGER_SET) is -- output set to standard output
    NOT_FIRST:BOOLEAN:=false;
  begin 
    Put('{');
    if not Empty(S)  then
      for I in S.all'range loop 
        if S.all(I) then
		if NOT_FIRST then Put(',');
		end if; 
		NOT_FIRST:=TRUE; Put(I);
        end if;
      end loop;
    end if;
    Put('}');
  end Put;

  procedure NORMALIZE(S:in out INTEGER_SET)is
	dummy:integer;
  begin
	dummy:=S.all'FIRST; return;
  exception
	when CONSTRAINT_ERROR => S:= new DATA'(ELEMENT=>FALSE);return;
  end NORMALIZE;

  procedure Put(I:INTEGER; INTO:in out INTEGER_SET) is
  begin NORMALIZE(INTO);
	INTO.all(I):=true;
  end Put;

  procedure Getmin(I: out integer; FROM:in out INTEGER_SET) is
  	M:integer:=Min(FROM);
  begin Take(M,FROM); I:=M;
  end Getmin;

  procedure Get(I: out integer; FROM:in out INTEGER_SET) is
  begin  Getmin(I,FROM);
  end Get;


  procedure Getmax(I: out integer; FROM:in out INTEGER_SET) is
  	M:integer:=max(FROM);
  begin Take(M,FROM); I:=M;
  end Getmax;

  procedure Take(I: INTEGER; FROM:in out INTEGER_SET) is
  begin FROM.all(I):=FALSE;
  end Take;

end INTEGER_SETS;