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.\" ========================================================================
.\"
.IX Title "RDF::Trine::Iterator 3pm"
.TH RDF::Trine::Iterator 3pm 2024-01-13 "perl v5.38.2" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
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.nh
.SH NAME
RDF::Trine::Iterator \- Iterator class for SPARQL query results
.SH VERSION
.IX Header "VERSION"
This document describes RDF::Trine::Iterator version 1.019.
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 6
\&    use RDF::Trine::Iterator;
\&    my $iterator = RDF::Trine::Iterator\->new( \e&data, \*(Aqbindings\*(Aq, \e@names );
\&    while (my $row = $iterator\->next) {
\&        my @vars        = keys %$row;
\&        # do something with @vars
\&    }
.Ve
.SH METHODS
.IX Header "METHODS"
.ie n .IP """new ( \e@results, $type, \e@names, %args )""" 4
.el .IP "\f(CWnew ( \e@results, $type, \e@names, %args )\fR" 4
.IX Item "new ( @results, $type, @names, %args )"
.PD 0
.ie n .IP """new ( \e&results, $type, \e@names, %args )""" 4
.el .IP "\f(CWnew ( \e&results, $type, \e@names, %args )\fR" 4
.IX Item "new ( &results, $type, @names, %args )"
.PD
Returns a new SPARQL Result interator object. Results must be either
an reference to an array containing results or a CODE reference that
acts as an iterator, returning successive items when called, and
returning undef when the iterator is exhausted.
.Sp
\&\f(CW$type\fR should be one of: bindings, boolean, graph.
.ie n .IP """type""" 4
.el .IP \f(CWtype\fR 4
.IX Item "type"
Returns the underlying result type (boolean, graph, bindings).
.ie n .IP """is_boolean""" 4
.el .IP \f(CWis_boolean\fR 4
.IX Item "is_boolean"
Returns true if the underlying result is a boolean value.
.ie n .IP """is_bindings""" 4
.el .IP \f(CWis_bindings\fR 4
.IX Item "is_bindings"
Returns true if the underlying result is a set of variable bindings.
.ie n .IP """is_graph""" 4
.el .IP \f(CWis_graph\fR 4
.IX Item "is_graph"
Returns true if the underlying result is an RDF graph.
.ie n .IP """to_string ( $format )""" 4
.el .IP "\f(CWto_string ( $format )\fR" 4
.IX Item "to_string ( $format )"
Returns a string representation of the stream data in the specified
\&\f(CW$format\fR. If \f(CW$format\fR is missing, defaults to XML serialization.
Other options are:
.Sp
.Vb 1
\&  http://www.w3.org/2001/sw/DataAccess/json\-sparql/
.Ve
.ie n .IP """from_string ( $xml )""" 4
.el .IP "\f(CWfrom_string ( $xml )\fR" 4
.IX Item "from_string ( $xml )"
Returns a new iterator using the supplied XML string in the SPARQL XML Results format.
.ie n .IP """from_bytes ( $xml )""" 4
.el .IP "\f(CWfrom_bytes ( $xml )\fR" 4
.IX Item "from_bytes ( $xml )"
Returns a new iterator using the supplied XML byte sequence (note: not character data)
in the SPARQL XML Results format.
.ie n .IP """from_json ( $json )""" 4
.el .IP "\f(CWfrom_json ( $json )\fR" 4
.IX Item "from_json ( $json )"
.PD 0
.ie n .IP """next_result""" 4
.el .IP \f(CWnext_result\fR 4
.IX Item "next_result"
.ie n .IP """next""" 4
.el .IP \f(CWnext\fR 4
.IX Item "next"
.PD
Returns the next item in the stream.
.ie n .IP """peek""" 4
.el .IP \f(CWpeek\fR 4
.IX Item "peek"
Returns the next value from the iterator without consuming it. The value will
remain in queue until the next call to \f(CW\*(C`next\*(C'\fR.
.ie n .IP """current""" 4
.el .IP \f(CWcurrent\fR 4
.IX Item "current"
Returns the current item in the stream.
.ie n .IP """end""" 4
.el .IP \f(CWend\fR 4
.IX Item "end"
.PD 0
.ie n .IP """finished""" 4
.el .IP \f(CWfinished\fR 4
.IX Item "finished"
.PD
Returns true if the end of the stream has been reached, false otherwise.
.ie n .IP """open""" 4
.el .IP \f(CWopen\fR 4
.IX Item "open"
Returns true if the first element of the stream has been retrieved, false otherwise.
.ie n .IP """close""" 4
.el .IP \f(CWclose\fR 4
.IX Item "close"
Closes the stream. Future attempts to retrieve data from the stream will act as
if the stream had been exhausted.
.ie n .IP """concat ( $stream )""" 4
.el .IP "\f(CWconcat ( $stream )\fR" 4
.IX Item "concat ( $stream )"
Returns a new stream resulting from the concatenation of the referant and the
argument streams. The new stream uses the stream type, and optional binding
names and \f(CW\*(C`<%args\*(C'\fR> from the referant stream.
.ie n .IP """seen_count""" 4
.el .IP \f(CWseen_count\fR 4
.IX Item "seen_count"
Returns the count of elements that have been returned by this iterator at the
point of invocation.
.ie n .IP """get_boolean""" 4
.el .IP \f(CWget_boolean\fR 4
.IX Item "get_boolean"
Returns the boolean value of the first item in the stream.
.ie n .IP """get_all""" 4
.el .IP \f(CWget_all\fR 4
.IX Item "get_all"
Returns an array containing all the items in the stream.
.ie n .IP """construct_args""" 4
.el .IP \f(CWconstruct_args\fR 4
.IX Item "construct_args"
Returns the arguments necessary to pass to a stream constructor
to re-create this stream (assuming the same closure as the first
argument).
.ie n .IP """each ( \e&callback )""" 4
.el .IP "\f(CWeach ( \e&callback )\fR" 4
.IX Item "each ( &callback )"
Calls the callback function once for each item in the iterator, passing the
item as an argument to the function. Any arguments to \f(CW\*(C`each\*(C'\fR beyond the
callback function will be passed as supplemental arguments to the callback
function.
.SH FUNCTIONS
.IX Header "FUNCTIONS"
.ie n .IP """sgrep { COND } $stream""" 4
.el .IP "\f(CWsgrep { COND } $stream\fR" 4
.IX Item "sgrep { COND } $stream"
.PD 0
.ie n .IP """smap { EXPR } $stream""" 4
.el .IP "\f(CWsmap { EXPR } $stream\fR" 4
.IX Item "smap { EXPR } $stream"
.ie n .IP """swatch { EXPR } $stream""" 4
.el .IP "\f(CWswatch { EXPR } $stream\fR" 4
.IX Item "swatch { EXPR } $stream"
.PD
.SH DEPENDENCIES
.IX Header "DEPENDENCIES"
JSON
.PP
Scalar::Util
.PP
XML::SAX
.SH BUGS
.IX Header "BUGS"
Please report any bugs or feature requests to through the GitHub web interface
at <https://github.com/kasei/perlrdf/issues>.
.SH AUTHOR
.IX Header "AUTHOR"
Gregory Todd Williams  \f(CW\*(C`<gwilliams@cpan.org>\*(C'\fR
.SH COPYRIGHT
.IX Header "COPYRIGHT"
Copyright (c) 2006\-2012 Gregory Todd Williams. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.