/* Booleans, Equality/Equivalence
 */

#include "scheme.h"

Object P_Booleanp (x) Object x; {
    return TYPE(x) == T_Boolean ? True : False;
}

Object P_Not (x) Object x; {
    return Truep (x) ? False : True;
}

Object P_Eq (x1, x2) Object x1, x2; {
    return EQ(x1, x2) ? True : False;
}

Object P_Eqv (x1, x2) Object x1, x2; {
    return Eqv (x1, x2) ? True : False;
}

Object P_Equal (x1, x2) Object x1, x2; {
    return Equal (x1, x2) ? True : False;
}

Eqv (x1, x2) Object x1, x2; {
    register t1, t2;
    if (EQ(x1, x2))
	return 1;
    t1 = TYPE(x1);
    t2 = TYPE(x2);
    if (Numeric (t1) && Numeric (t2))
	return Generic_Equal (x1, x2);
    if (t1 != t2)
	return 0;
    switch (t1) {
    case T_String:
        return STRING(x1)->size == 0 && STRING(x2)->size == 0;
    case T_Vector:
	return VECTOR(x1)->size == 0 && VECTOR(x2)->size == 0;
    case T_Primitive:
	return strcmp (PRIM(x1)->name, PRIM(x2)->name) == 0;
    default:
	if (t1 < 0 || t1 >= MAX_TYPE || !Types[t1].name)
	    Panic ("bad type in eqv");
	if (Types[t1].eqv == NOFUNC)
	    return 0;
	return (*Types[t1].eqv)(x1, x2);
    }
    /*NOTREACHED*/
}

Equal (x1, x2) Object x1, x2; {
    register t1, t2, i;

again:
    if (EQ(x1, x2))
	return 1;
    t1 = TYPE(x1);
    t2 = TYPE(x2);
    if (Numeric (t1) && Numeric (t2))
	return Generic_Equal (x1, x2);
    if (t1 != t2)
	return 0;
    switch (t1) {
    case T_Boolean:
    case T_Character:
    case T_Compound:
    case T_Control_Point:
    case T_Promise:
    case T_Port:
    case T_Macro:
	return 0;
    case T_Primitive:
	return Eqv (x1, x2);
    case T_Symbol:
	return Equal (SYMBOL(x1)->name, SYMBOL(x2)->name) &&
	    Equal (SYMBOL(x1)->plist, SYMBOL(x2)->plist);
    case T_Environment:
    case T_Pair:
	if (!Equal (Car (x1), Car (x2)))
	    return 0;
	x1 = Cdr (x1); x2 = Cdr (x2);
	goto again;
    case T_String:
	return STRING(x1)->size == STRING(x2)->size &&
	    bcmp (STRING(x1)->data, STRING(x2)->data, STRING(x1)->size) == 0;
    case T_Vector:
	if (VECTOR(x1)->size != VECTOR(x2)->size)
	    return 0;
	for (i = 0; i < VECTOR(x1)->size; i++)
	    if (!Equal (VECTOR(x1)->data[i], VECTOR(x2)->data[i]))
		return 0;
	return 1;
    default:
	if (t1 < 0 || t1 >= MAX_TYPE || !Types[t1].name)
	    Panic ("bad type in equal");
	if (Types[t1].equal == NOFUNC)
	    return 0;
	return (*Types[t1].equal)(x1, x2);
    }
    /*NOTREACHED*/
}