directive

# `alias/2`

## Description

    alias(Entity, [Name/Arity as Alias/Arity, ...])
    alias(Entity, [Name//Arity as Alias//Arity, ...])

Declares predicate and grammar rule non-terminal aliases. A predicate (non-terminal) alias is an alternative name for a predicate (non-terminal) declared or defined in an extended protocol, an implemented protocol, an extended category, an imported category, an extended prototype, an instantiated class, or a specialized class. Predicate aliases may be used to solve conflicts between imported or inherited predicates. It may also be used to give a predicate (non-terminal) a name more appropriated in its usage context. This directive may be used in objects, protocols, and categories.

Predicate (and non-terminal) aliases are specified using (preferably) the notation `Name/Arity as Alias/Arity` or, in alternative, the notation `Name/Arity::Alias/Arity`.

It is also possible to declare predicate and grammar rule non-terminal aliases in implicit qualification directives for sending messages to objects and calling module predicates.

## Template and modes

    alias(@entity_identifier, +list(predicate_indicator_alias))
    alias(@entity_identifier, +list(non_terminal_indicator_alias))

## Examples

    % resolve a predicate name conflict:
    :- alias(list, [member/2 as list_member/2]).
    :- alias(set,  [member/2 as set_member/2]).

    % define an alternative name for a non-terminal:
    :- alias(words, [singular//0 as peculiar//0]).

See also

uses/2, use_module/2, uses/1