or.md
In rswipl: Embed 'SWI'-'Prolog'

class or {#class-or}

Class or defines a logical or for its associated statements. An or is not just binary but can have any number of arguments.

When executed, or will execute its argument code objects starting from the first. It stops with success as soon as one of the arguments succeeds or returns failure if no argument succeed. An or without arguments simply fails.

See also class if, class and and class not.

@see topic Conditions

or<-members: chain List of disjunctive statements. Note that class or delegates to this chain, so all methods applicable to chains may be used to manipulate the set of statements in the or.

or->_execute Execute the code objects from <-members until one succeeds or the end of the chain is reached. Succeeds in the first case and fails in the second.
or->initialise: test=code ... Create an or object from a series of statements. Or objects are almost exclusively used to realise disjunction in conditions for if objects or while objects.