src/swipl-devel/packages/xpce/man/refmanual/md/equal.md

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class equal {#class-equal}

Test for equality. Succeeds if both <-left and <-right are equal (compared by reference). The following example returns the first object called gnu in Chain:

get(Chain, find, @arg1?name == gnu, Gnu)

See also class \== and object ->equal.

@see object->equal @see class \== @see topic Conditions @see object->is_on @see object->is_off @see object->has_value

Instance variables {#class-equal-instvars}

• equal-left Operant. If it is a function object, it will be evaluated by ->_execute.

• equal-right Inherits description from: ==-left

Send methods {#class-equal-send}

• equal->_execute If either or both operant is a function, evaluate it. Next succeed if the references of both operants is the same.

• equal->initialise Create from <-left and <-right operant. Either or both may be a function, which is evaluated by ->_execute.

rswipl documentation built on June 16, 2026, 5:07 p.m.