BUILTINS

Used Exports

	MODULE BUILTINS; (pseudo module declaring all the builtin types and procedures )

	TYPE
	BOOLEAN * = RECORD (* the truth values TRUE and FALSE *) END;
	CHAR * = RECORD (* the characters of a standard character set *) END;
	INTEGER * = RECORD (* the integers *) END;
	REAL * = RECORD (* real numbers *) END;
	BYTE * = RECORD (* the integers between 0 and 255 *) END;
	SET * = RECORD (* the sets of integers between 0 and an implementation-dependent limit *) END;

	(* LONGINT is synonym to INTEGER, LONGREAL to REAL *)
	LONGINT * = RECORD (* INTEGER *) END;
	LONGREAL * = RECORD (* REAL *) END;

	(* pseudo types used by the builtin procedures *)
	NumericType = RECORD (* any numeric type *) END;
	ArrayType = ARRAY 1 OF NumericType;
	CharBooleanSet = RECORD (* one of CHAR, BOOLEAN, SET *) END;
	PointerType = RECORD (* pointer type *) END;

	PROCEDURE ABS *(x: NumericType): NumericType;
	BEGIN RETURN (* absolute value of *) x
	END ABS;

	PROCEDURE ODD *(x: INTEGER): BOOLEAN;
	BEGIN RETURN x MOD 2 = 1
	END ODD;

	PROCEDURE LEN *(v: ArrayType): INTEGER;
	BEGIN RETURN (* length of array *) v
	END LEN;

	PROCEDURE LSL *(x, n: INTEGER): INTEGER;
	BEGIN RETURN x * (* 2^ *) n
	END LSL;

	PROCEDURE ASR *(x, n: INTEGER): INTEGER;
	BEGIN RETURN x DIV (* 2^ *) n
	END ASR;

	PROCEDURE ROR *(x, n: INTEGER): INTEGER;
	BEGIN RETURN x (* rotated right by n bits *)
	END ROR;

	PROCEDURE FLOOR *(x: REAL): INTEGER;
	BEGIN RETURN x (* rounded down *)
	END FLOOR;

	PROCEDURE FLT *(x: INTEGER): REAL;
	BEGIN RETURN x
	END FLT;

	PROCEDURE ORD *(x: CharBooleanSet): INTEGER;
	BEGIN RETURN (* ordinal number of *) x
	END ORD;

	PROCEDURE CHR *(x: INTEGER): CHAR;
	BEGIN RETURN (* character with ordinal number *) x
	END CHR;

	PROCEDURE INC (VAR v: INTEGER; (OPTIONAL*) n: INTEGER);
	BEGIN v := v + n (* or 1 if not given *)
	END INC;

	PROCEDURE DEC (VAR v: INTEGER; (OPTIONAL*) n: INTEGER);
	BEGIN v := v - n (* or 1 if not given *)
	END DEC;

	PROCEDURE INCL *(VAR v: SET; x: INTEGER);
	BEGIN v := v + (* set of only *) x
	END INCL;

	PROCEDURE EXCL *(VAR v: SET; x: INTEGER);
	BEGIN v := v - (* set of only *) x
	END EXCL;

	PROCEDURE NEW *(VAR v: PointerType);
	BEGIN (* allocate pointer *)
	END NEW;

	PROCEDURE ASSERT *(VAR b: BOOLEAN);
	BEGIN IF ~b THEN (* abort *) END
	END ASSERT;

	PROCEDURE PACK *(VAR x: REAL; n: INTEGER);
	BEGIN (* pack x * 2 ^ n into x *)
	END PACK;

	PROCEDURE UNPK *(VAR x: REAL; VAR n: INTEGER);
	BEGIN (* unpack x into x * 2 ^ n so that 1.0 <= x < 2.0 *)
	END UNPK;

	(* UML, LED, ADC, SBC are not in language definition,
	but UML, ADC and SBC are not used by Project Oberon *)

	PROCEDURE LED *(VAR n: INTEGER);
	BEGIN (* display n on LEDs *)
	END LED;

	END BUILTINS.