SPVM::EqualityChecker - Interface Type for Object Equality Checking Callback

Name  Usage  Description  Interface Methods  Class Methods  default_equality_checker  Copyright & License 

---

Name

SPVM::EqualityChecker − Interface Type for Object Equality Checking Callback

Usage

use EqualityChecker;
use Point;
my $equality_checker = (EqualityChecker)method : int ($object1 : object, $object2 : object) {
my $point1 = (Point)$object1;
my $point2 = (Point)$object2;
if ($point1−>x == $point2−>x && $point1−>y == $point2−>y) {
return 1;
}
else {
return 0;
}
};
my $point1 = Point−>new(1, 2);
my $point2 = Point−>new(5, 6);
my $is_equal = $equality_checker−>($point1, $point2);

Description

EqualityChecker is the interface type for the object equality checking callback.

Interface Methods

"required method : int ($object1 : object, $object2 : object)"

The implementation must receive two objects and if they are equal, return 1. Otherwise, return 0.

Class Methods

default_equality_checker

"static method default_equality_checker : EqualityChecker ();"

Returns a default default equality checker.

The implementation of the default equality checker is

method : int ($object1 : EqualityCheckable, $object2 : EqualityCheckable) {
my $eq = 0;
if ($object1 && $object2) {
$eq = $object1−>eq($object1, $object2);
}
elsif ($object1) {
$eq = 0;
}
elsif ($object2) {
$eq = 0;
}
else {
$eq = 1;
}
return $eq;
};

If $object1 and $object2 are defined, the check of equality is perfermed by EqualityCheckable#eq method in the class of $object1, and returns its return value.

If only $object1 is defined, returns 0.

If only $object2 is defined, returns 0.

If both $object1 and $object2 are not defined, returns 1.

Copyright & License

Copyright (c) 2023 Yuki Kimoto

MIT License

---