NAME

Attean::API::Expression - SPARQL expressions

VERSION

This document describes Attean::API::Expression version 0.021

DESCRIPTION

The Attean::API::Expression role defines a common API for SPARQL expressions consisting of logical, numeric, and function operators, constant terms, and variables. Expressions may be evaluated in the context of a Attean::API::Result object, and either return a Attean::API::Term object or throw a type error exception.

ROLES

This role consumes the Attean::API::DirectedAcyclicGraph role which provide the following methods:

is_leaf
walk( prefix => \&pre_cb, postfix => \&pre_cb )
cover( prefix => \&pre_cb, postfix => \&pre_cb )

and the following attributes:

children

ATTRIBUTES

The following attributes exist:

operator

A string indicating the expression operator (e.g. '+' or '||').

REQUIRED METHODS

The following methods are required by the Attean::API::Expression role:

as_string

Returns a string serialization of the expression object.

BUGS

Please report any bugs or feature requests to through the GitHub web interface at https://github.com/kasei/attean/issues.

SEE ALSO

AUTHOR

Gregory Todd Williams <gwilliams@cpan.org>

COPYRIGHT

Copyright (c) 2014--2018 Gregory Todd Williams. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.