NAME

       Attean::API::Iterator - Typed iterator

VERSION

       This document describes Attean::API::Iterator version 0.033

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--2022 Gregory Todd Williams.  This program is free software; you can
       redistribute it and/or modify it under the same terms as Perl itself.