INTERFACE TWord;

This interface provides simulations of the target machine's unsigned integer operations.

Unless otherwise specified, the arithmetic operations defined below return TRUE if they succeed in producing a new target value, otherwise they return FALSE.

FROM Target IMPORT Int;

PROCEDURE New (READONLY chars: ARRAY OF CHAR;  base: [2..16];  n: CARDINAL;
               VAR i: Int): BOOLEAN;

converts the string of characters in 'chars' representing a base 'base' number to an integer value in 'i'

PROCEDURE Add (READONLY a, b: Int;  VAR i: Int);

returns 'Word.Plus (a, b)'

PROCEDURE Subtract (READONLY a, b: Int;  VAR i: Int);

returns 'Word.Minus (a, b)'

PROCEDURE Multiply (READONLY a, b: Int;  VAR i: Int);

returns 'Word.Times (a, b)'

PROCEDURE Div (READONLY a, b: Int;  VAR i: Int): BOOLEAN;

returns 'Word.Divide (a, b)' unless b is zero.

PROCEDURE Mod (READONLY a, b: Int;  VAR i: Int): BOOLEAN;

returns 'Word.Mod (a, b)' unless b is zero.

PROCEDURE DivMod (READONLY x, y: Int;  VAR q, r: Int);

returns 'q = x DIV y', and 'r = x MOD y', but assumes that 'y # 0'

PROCEDURE LT (READONLY a, b: Int): BOOLEAN;

returns 'Word.LT (a, b)'

PROCEDURE LE (READONLY a, b: Int): BOOLEAN;

returns 'Word.LE (a, b)'

PROCEDURE And (READONLY a, b: Int;  VAR i: Int);

returns 'Word.And (a, b)'

PROCEDURE Or (READONLY a, b: Int;  VAR i: Int);

returns 'Word.Or (a, b)'

PROCEDURE Xor (READONLY a, b: Int;  VAR i: Int);

returns 'Word.Xor (a, b)'

PROCEDURE Not (READONLY a: Int;  VAR i: Int);

returns 'Word.Not (a)'

PROCEDURE Shift (READONLY x: Int;  n: INTEGER;  VAR r: Int);

returns 'Word.Shift (x, n)'

PROCEDURE Rotate (READONLY x: Int;  n: INTEGER;  VAR r: Int);

returns 'Word.Rotate (x, n)'

PROCEDURE Extract (READONLY x: Int;  i, n: CARDINAL;  VAR r: Int): BOOLEAN;

returns 'Word.Extract (x, i, n)'

PROCEDURE Insert (READONLY x, y: Int;  i, n: CARDINAL;  VAR r: Int): BOOLEAN;

returns 'Word.Insert (x, y, i, n)'

END TWord.