Attean::API::Expression3pm

Version

This document describes Attean::API::Expression version 0.035

Overview

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.