search-xapian/Xapian/PositionIterator.pm

   1 package Search::Xapian::PositionIterator;
   2
   3 use 5.006;
   4 use strict;
   5 use warnings;
   6 use Carp;
   7 use Scalar::Util 'blessed';
   8
   9 require DynaLoader;
  10
  11 our @ISA = qw(DynaLoader);
  12
  13 # Preloaded methods go here.
  14
  15 # In a new thread, copy objects of this class to unblessed, undef values.
  16 sub CLONE_SKIP { 1 }
  17
  18 use overload '++' => sub { $_[0]->inc() },
  19              '='  => sub { $_[0]->clone() },
  20              'eq' => sub { $_[0]->equal($_[1]) },
  21              'ne' => sub { $_[0]->nequal($_[1]) },
  22              '==' => sub { $_[0]->equal($_[1]) },
  23              '!=' => sub { $_[0]->nequal($_[1]) },
  24              '""' => sub { $_[0]->get_description() },
  25              '0+' => sub { $_[0]->get_termpos() },
  26              'fallback' => 1;
  27
  28 sub clone() {
  29   my $self = shift;
  30   my $class = ref( $self );
  31   my $copy = new2( $self );
  32   bless $copy, $class;
  33   return $copy;
  34 }
  35
  36 sub equal() {
  37   my ($self, $other) = @_;
  38   if( blessed($other) && $other->isa('Search::Xapian::PositionIterator') ) {
  39     $self->equal1($other);
  40   } else {
  41     ($self+0) == ($other+0);
  42   }
  43 }
  44
  45 sub nequal() {
  46   my ($self, $other) = @_;
  47   if( blessed($other) && $other->isa('Search::Xapian::PositionIterator') ) {
  48     $self->nequal1($other);
  49   } else {
  50     ($self+0) != ($other+0);
  51   }
  52 }
  53
  54
  55 sub new() {
  56   my $class = shift;
  57   my $iterator;
  58   my $invalid_args;
  59   if( scalar(@_) == 0 ) {
  60     $iterator = new1();
  61   } elsif( scalar(@_) == 1 and ref( $_[1] ) eq $class ) {
  62     $iterator = new2(@_);
  63   } else {
  64     $invalid_args = 1;
  65   }
  66   if( $invalid_args ) {
  67     Carp::carp( "USAGE: $class->new(), $class->new(\$iterator)" );
  68     exit;
  69   }
  70   bless $iterator, $class;
  71   return $iterator;
  72 }
  73
  74 1;
  75
  76 __END__
  77
  78 =head1 NAME
  79
  80 Search::Xapian::PositionIterator - Iterate over sets of positions.
  81
  82 =head1 DESCRIPTION
  83
  84 This iterator represents a stream of positions for a term. It overloads
  85 C<++> for advancing the iterator, or you can explicitly call the C<inc> method.
  86 This class also overloads C<eq>, C<ne>, C<==>, C<!=>, C<"">
  87 (stringification) and C<0+> (conversion to an integer).
  88
  89 =head1 METHODS
  90
  91 =over 4
  92
  93 =item new
  94
  95 Constructor. Defaults to an uninitialized iterator.
  96
  97 =item clone
  98
  99 =item inc
 100
 101 Advance the iterator by one. (Called implictly by C<++> overloading).
 102
 103 =item skip_to <termpos>
 104
 105 Skip the iterator to term position termpos, or the first term position after
 106 termpos if termpos isn't in the list of term positions being iterated.
 107
 108 =item equal <term>
 109
 110 Checks if a term is the same as this term. Also overloaded to the C<eq>
 111 and C<==> operators.
 112
 113 =item nequal <term>
 114
 115 Checks if a term is different from this term. Also overloaded to the C<ne>
 116 and C<!=> operators.
 117
 118 =item get_termpos
 119
 120 Return the term position the iterator is currently on. Also implemented as
 121 conversion to an integer.
 122
 123 =item get_description
 124
 125 Return a description of this object.  Also implemented as stringification.
 126
 127 =back
 128
 129 =head1 SEE ALSO
 130
 131 L<Search::Xapian>,
 132 L<Search::Xapian::Document>
 133
 134 =cut