ls9-types.nw

Special Objects

<<ls9 definitions>>=
#define ATOM_TAG	0x01	/* Atom, CAR = type, CDR = next */
#define MARK_TAG	0x02	/* Mark */
#define TRAV_TAG	0x04	/* Traversal */
#define VECTOR_TAG	0x08	/* Vector, CAR = type, CDR = content */
#define PORT_TAG	0x10	/* Atom is an I/O port (with ATOM_TAG) */
#define USED_TAG	0x20	/* Port: used flag */
#define LOCK_TAG	0x40	/* Port: locked (do not close) */
#define CONST_TAG	0x80	/* Node is immutable */
@

<<ls9 definitions>>=
#define NIL		((full)-1)
#define TRUE		((full)(NIL - 1))
#define EOFMARK		((full)(NIL - 2))
#define UNDEF		((full)(NIL - 3))
#define RPAREN		((full)(NIL - 4))
#define DOT		((full)(NIL - 5))
@

Tagged data types

<<ls9 definitions>>=
#define T_BYTECODE	((full)(DOT - 1))
#define T_CATCHTAG	((full)(T_BYTECODE - 1))
#define T_CHAR		((full)(T_BYTECODE - 2))
#define T_CLOSURE	((full)(T_BYTECODE - 3))
#define T_FIXNUM	((full)(T_BYTECODE - 4))
#define T_INPORT	((full)(T_BYTECODE - 5))
#define T_OUTPORT	((full)(T_BYTECODE - 6))
#define T_STRING	((full)(T_BYTECODE - 7))
#define T_SYMBOL	((full)(T_BYTECODE - 8))
#define T_VECTOR	((full)(T_BYTECODE - 9))
@

<<ls9 macros>>=
#define specialp(x)	((full)(x) >= T_VECTOR)

#define cons(a, d)	cons3((a), (d), 0)
#define mkatom(a, d)	cons3(a, d, ATOM_TAG)

#define mkfix(n) mkatom(T_FIXNUM, mkatom(n, NIL))

#define mkchar(c) mkatom(T_CHAR, mkatom((c) & 0xff, NIL))

#define fixval(n) (cadr(n))

#define charval(n) (cadr(n))

#define add_ovfl(a,b) \
	((((ifull)(b) > 0) && ((ifull)(a) > IFULL_MAX - (ifull)(b))) || \
	 (((ifull)(b) < 0) && ((ifull)(a) < IFULL_MIN - (ifull)(b))))

#define sub_ovfl(a,b) \
	((((ifull)(b) < 0) && ((ifull)(a) > IFULL_MAX + (ifull)(b))) || \
	 (((ifull)(b) > 0) && ((ifull)(a) < IFULL_MIN + (ifull)(b))))
@

<<ls9 impl>>=
full mkstr(char *s, size_t k) {
	full	n;

	if (0 == k) return Nullstr;
	n = newvec(T_STRING, k+1);
	if (NULL == s) {
		memset(string(n), 0, k+1);
	}
	else {
		memcpy(string(n), s, k);
		string(n)[k] = 0;
	}
	return n;
}

full mkvec(full k) {
	full	n, *v, i;
	if (0 == k) return Nullvec;
	n = newvec(T_VECTOR, k * sizeof(full));
	v = vector(n);
	for (i=0; i<k; i++) v[i] = NIL;
	return n;
}

full mkport(full portno, full type) {
	full	n, pf;

	pf = Port_flags[portno];
	Port_flags[portno] |= LOCK_TAG;
	n = mkatom(portno, NIL);
	n = cons3(type, n, ATOM_TAG|PORT_TAG);
	Port_flags[portno] = (byte)pf;
	return n;
}
@