Method `^()


Method `^

mixed `^(mixed arg1)
mixed `^(mixed arg1, mixed arg2, mixed ... extras)
mixed `^(object arg1, mixed arg2)
mixed `^(mixed arg1, object arg2)
int `^(int arg1, int arg2)
string `^(string arg1, string arg2)
array `^(array arg1, array arg2)
mapping `^(mapping arg1, mapping arg2)
multiset `^(multiset arg1, multiset arg2)
type `^(program|type arg1, program|type arg2)

Description

Exclusive or.

Every expression with the ^ operator becomes a call to this function, i.e. a^b is the same as predef::`^(a,b).

Returns

If there's a single argument, that argument is returned.

If there are more than two arguments, the result is: `^(`^(arg1arg2), @extras).

Otherwise, if arg1 is an object with an lfun::`^(), that function is called with arg2 as argument, and its result is returned.

Otherwise, if arg2 is an object with an lfun::``^(), that function is called with arg1 as argument, and its result is returned.

Otherwise the result depends on the argument types:

arg1 can have any of the following types:
int

Bitwise exclusive or of arg1 and arg2.

string

The result is a string where each character is the bitwise exclusive or of the characters in the same position in arg1 and arg2. The arguments must be strings of the same length.

array

The result is an array with the elements in arg1 that doesn't occur in arg2 concatenated with those in arg2 that doesn't occur in arg1 (according to `>, `< and `==). The order between the elements that come from the same argument is kept.

Every element is only matched once against an element in the other array, so if one contains several elements that are equal to each other and are more than their counterparts in the other array, the rightmost remaining elements are kept.

mapping

The result is like arg1 but with the entries from arg1 and arg2 whose indices are different between them (according to hash_value and `==).

multiset

The result is like arg1 but with the entries from arg1 and arg2 that are different between them (according to `>, `< and `==). Subsequences with orderwise equal entries (i.e. where `< returns false) are handled just like the array case above.

type|program

The result is a type computed like this: (arg1&~arg2)|(~arg1&arg2).

The function is not destructive on the arguments - the result is always a new instance.

Note

If this operator is used with arrays or multisets containing objects which implement lfun::`==() but not lfun::`>() and lfun::`<(), the result will be undefined.

See also

`&(), `|(), lfun::`^(), lfun::``^()