---
name: "RDF::Query::Algebra"
section: "3pm"
platform: "linux"
package: "librdf-query-perl"
version: "2.919-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/RDF::Query::Algebra"
---

# RDF::Query::Algebra(3pm)

Base class for Algebra expressions

## NAME

RDF::Query::Algebra - Base class for Algebra expressions

## VERSION

This document describes RDF::Query::Algebra version 2.919.

## METHODS

- "potentially\_bound"

  Returns a list of the variable names used in this algebra expression that will bind values during execution.

- "referenced\_blanks"

  Returns a list of the blank node names used in this algebra expression.

- "referenced\_functions"

  Returns a list of the Function URIs used in this algebra expression.

- "check\_duplicate\_blanks"

  Returns true if blank nodes respect the SPARQL rule of no blank-label re-use across BGPs, otherwise throws a RDF::Query::Error::QueryPatternError exception.

- "qualify\_uris ( \\%namespaces, $base\_uri )"

  Returns a new algebra pattern where all referenced Resource nodes representing QNames (ns:local) are qualified using the supplied `%namespaces`.

- "bind\_variables ( \\%bound )"

  Returns a new algebra pattern with variables named in `%bound` replaced by their corresponding bound values.

- "is\_solution\_modifier"

  Returns true if this node is a solution modifier.

- "subpatterns\_of\_type ( $type \[, $block\] )"

  Returns a list of Algebra patterns matching `$type` (tested with `"isa"`). If `$block` is given, then matching stops descending a subtree if the current node is of type `$block`, continuing matching on other subtrees. This list includes the current algebra object if it matches `$type`, and is generated in infix order.

- "from\_sse ( $sse, \\%context )"

  Given an SSE serialization, returns the corresponding algebra expression.

## FUNCTIONS

- "triple ( $subj, $pred, $obj )"

  Returns a RDF::Query::Algebra::Triple object with the supplied node objects.

- "bgp ( @triples )"

  Returns a RDF::Query::Algebra::BasicGraphPattern object with the supplied triples.

- "ggp ( @patterns )"

  Returns a RDF::Query::Algebra::GroupGraphPattern object with the supplied algebra patterns.

## AUTHOR

```
 Gregory Todd Williams <gwilliams@cpan.org>
```