Attean::API::Iterator(3pm)

NAME

Attean::API::Iterator - Typed iterator

VERSION

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

DESCRIPTION

The Attean::API::Iterator role defines a common API for typed iterators. This package also defines several type-specific iterator roles:

•: Attean::API::TripleIterator

•: Attean::API::QuadIterator

•: Attean::API::MixedStatementIterator

•: Attean::API::ResultIterator

These roles will automatically be applied to iterators during construction when appropriate.

ATTRIBUTES

The following attributes exist:

"item_type": A string indicating the type of elements returned by the iterator.

REQUIRED METHODS

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

"next": Returns the next element from the iterator, or "undef" upon exhaustion.

METHODS

The Attean::API::Iterator role provides default implementations of the following methods:

"elements": Returns a list of all remaining elements in the iterator.

"map( \&mapper [, $result_type] )": Returns a new Attean::API::Iterator object with each element mapped using the supplied &mapper function. If the iterator elements are of the same type as those in the referent iterator, only a mapping function is required. Otherwise, the supplied Type::Tiny $result_type object must indicate the new iterator's type information.

grep( \&filter ): Returns a new Attean::API::Iterator object that filters elements from the referent iterator based on whether calling &filter( $element ) for each $element results in a true value.

offset( $offset ): Returns the Attean::API::Iterator referent after skipping the first $offset elements.

limit( $limit ): Returns a new Attean::API::Iterator object which returns the first $limit elements of the referent.

"materialize": Returns a new Attean::API::RepeatableIterator object containing all the elements from the referent.

debug( [$name] ): Print each item as it is consumed (with the string generated by "as_string"), prepended by $name.

Methods on Roles Supporting Stringification

For iterators over roles that provide an "as_string" method, extra methods are provided. These iterators are:

Attean::API::ResultOrTermIterator Attean::API::StatementIterator Attean::API::MixedStatementIterator Attean::API::ResultIterator Attean::API::TermIterator

They provide the following methods:

"uniq": Returns a new iterator providing unique results (based on the stringified value of the underlying elements).

BUGS

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

AUTHOR

Gregory Todd Williams "<[email protected]>"