• NAME
• VERSION
• DESCRIPTION
• ATTRIBUTES
• REQUIRED METHODS
• METHODS
  • Methods on Roles Supporting Stringification
• BUGS
• SEE ALSO
• AUTHOR
• COPYRIGHT

NAME

Attean::API::Iterator - Typed iterator

VERSION

This document describes Attean::API::Iterator version 0.030

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.

SEE ALSO

Attean::API::RepeatableIterator

AUTHOR

Gregory Todd Williams <gwilliams@cpan.org>

COPYRIGHT

Copyright (c) 2014--2020 Gregory Todd Williams. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.