1Attean::API::Iterator(3U)ser Contributed Perl DocumentatiAotntean::API::Iterator(3)
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NAME

6       Attean::API::Iterator - Typed iterator
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VERSION

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

12       The Attean::API::Iterator role defines a common API for typed
13       iterators.  This package also defines several type-specific iterator
14       roles:
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16       •   Attean::API::TripleIterator
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18       •   Attean::API::QuadIterator
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20       •   Attean::API::MixedStatementIterator
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22       •   Attean::API::ResultIterator
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24       These roles will automatically be applied to iterators during
25       construction when appropriate.
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ATTRIBUTES

28       The following attributes exist:
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30       "item_type"
31           A string indicating the type of elements returned by the iterator.
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REQUIRED METHODS

34       The following methods are required by the Attean::API::Iterator role:
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36       "next"
37           Returns the next element from the iterator, or "undef" upon
38           exhaustion.
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METHODS

41       The Attean::API::Iterator role provides default implementations of the
42       following methods:
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44       "elements"
45           Returns a list of all remaining elements in the iterator.
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47       "map( \&mapper [, $result_type] )"
48           Returns a new Attean::API::Iterator object with each element mapped
49           using the supplied &mapper function. If the iterator elements are
50           of the same type as those in the referent iterator, only a mapping
51           function is required.  Otherwise, the supplied Type::Tiny
52           $result_type object must indicate the new iterator's type
53           information.
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55       "grep( \&filter )"
56           Returns a new Attean::API::Iterator object that filters elements
57           from the referent iterator based on whether calling "&filter(
58           $element )" for each $element results in a true value.
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60       "offset( $offset )"
61           Returns the Attean::API::Iterator referent after skipping the first
62           $offset elements.
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64       "limit( $limit )"
65           Returns a new Attean::API::Iterator object which returns the first
66           $limit elements of the referent.
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68       "materialize"
69           Returns a new Attean::API::RepeatableIterator object containing all
70           the elements from the referent.
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72       "debug( [$name] )"
73           Print each item as it is consumed (with the string generated by
74           "as_string"), prepended by $name.
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76   Methods on Roles Supporting Stringification
77       For iterators over roles that provide an "as_string" method, extra
78       methods are provided. These iterators are:
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80       Attean::API::ResultOrTermIterator Attean::API::StatementIterator
81       Attean::API::MixedStatementIterator Attean::API::ResultIterator
82       Attean::API::TermIterator
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84       They provide the following methods:
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86       "uniq"
87           Returns a new iterator providing unique results (based on the
88           stringified value of the underlying elements).
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BUGS

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

95       Attean::API::RepeatableIterator
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AUTHOR

98       Gregory Todd Williams  "<gwilliams@cpan.org>"
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101       Copyright (c) 2014--2020 Gregory Todd Williams.  This program is free
102       software; you can redistribute it and/or modify it under the same terms
103       as Perl itself.
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107perl v5.34.0                      2022-01-20          Attean::API::Iterator(3)
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