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1
21
22 package org.armedbear.lisp;
23
24 import java.math.BigInteger  ;
25
26 public final class logxor extends Primitive
30 {
31 private logxor()
32 {
33 super("logxor", "&rest integers");
34 }
35
36 public LispObject execute()
37 {
38 return Fixnum.ZERO;
39 }
40
41 public LispObject execute(LispObject arg) throws ConditionThrowable
42 {
43 if (arg instanceof Fixnum || arg instanceof Bignum)
44 return arg;
45 return signal(new TypeError(arg, Symbol.INTEGER));
46 }
47
48 public LispObject execute(LispObject first, LispObject second)
49 throws ConditionThrowable
50 {
51 if (first instanceof Fixnum && second instanceof Fixnum)
52 return new Fixnum(((Fixnum)first).value ^ ((Fixnum)second).value);
53 BigInteger n1, n2;
54 if (first instanceof Fixnum)
55 n1 = ((Fixnum)first).getBigInteger();
56 else if (first instanceof Bignum)
57 n1 = ((Bignum)first).value;
58 else
59 return signal(new TypeError(first, Symbol.INTEGER));
60 if (second instanceof Fixnum)
61 n2 = ((Fixnum)second).getBigInteger();
62 else if (second instanceof Bignum)
63 n2 = ((Bignum)second).value;
64 else
65 return signal(new TypeError(second, Symbol.INTEGER));
66 return number(n1.xor(n2));
67 }
68
69 public LispObject execute(LispObject[] args) throws ConditionThrowable
70 {
71 final int limit = args.length;
72 int i = 0;
73 int r = 0;
75 do {
76 if (args[i] instanceof Fixnum) {
77 r ^= ((Fixnum)args[i]).value;
78 ++i;
79 } else
80 break;
81 } while (i < limit);
82 if (i == limit)
83 return number(r);
84 BigInteger result = BigInteger.valueOf(r);
86 while (i < limit) {
87 BigInteger n;
88 if (args[i] instanceof Fixnum)
89 n = ((Fixnum)args[i]).getBigInteger();
90 else if (args[i] instanceof Bignum)
91 n = ((Bignum)args[i]).value;
92 else
93 return signal(new TypeError(args[i], Symbol.INTEGER));
94 result = result.xor(n);
95 ++i;
96 }
97 return number(result);
98 }
99
100 private static final Primitive LOGXOR = new logxor();
101 }
102 |
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Java API By Example, From Geeks To Geeks.