NAME

       Attean::API::Expression - SPARQL expressions

VERSION

       This document describes Attean::API::Expression version 0.019

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.