[scpubgit/stemmatology.git] / lib / Text / Tradition / Parser / TEI.pm

package Text::Tradition::Parser::TEI;

use strict;
use warnings;
use Text::Tradition::Parser::Util qw( collate_variants );
use XML::LibXML;
use XML::LibXML::XPathContext;

=head1 NAME

Text::Tradition::Parser::TEI

=head1 DESCRIPTION

Parser module for Text::Tradition, given a TEI parallel-segmentation
file that describes a text and its variants.

=head1 METHODS

=over

=item B<parse>

parse( $tei_string );

Takes an initialized tradition and a string containing the TEI;
creates the appropriate nodes and edges on the graph, as well as
the appropriate witness objects.

=cut

my $text = {}; # Hash of arrays, one per eventual witness we find.
my $substitutions = {}; # Keep track of merged readings
my $app_anchors = {};   # Track apparatus references
my $app_ac = {};        # Save a.c. readings

# Create the package variables for tag names.

# Would really like to do this with varname variables, but apparently this
# is considered a bad idea.  The long way round then.
my( $LISTWIT, $WITNESS, $TEXT, $W, $SEG, $APP, $RDG, $LEM ) 
    = ( 'listWit', 'witness', 'text', 'w', 'seg', 'app', 'rdg', 'lem' );
sub make_tagnames {
    my( $ns ) = @_;
    if( $ns ) {
        $LISTWIT = "$ns:$LISTWIT";
        $WITNESS = "$ns:$WITNESS";
        $TEXT = "$ns:$TEXT";
        $W = "$ns:$W";
        $SEG = "$ns:$SEG";
        $APP = "$ns:$APP";
        $RDG = "$ns:$RDG";
        $LEM = "$ns:$LEM";
    }
}

# Parse the TEI file.
sub parse {
    my( $tradition, $xml_str ) = @_;
    
    # First, parse the XML.
    my $parser = XML::LibXML->new();
    my $doc = $parser->parse_string( $xml_str );
    my $tei = $doc->documentElement();
    my $xpc = XML::LibXML::XPathContext->new( $tei );
    my $ns;
    if( $tei->namespaceURI ) {
        $ns = 'tei';
        $xpc->registerNs( $ns, $tei->namespaceURI );
    }
    make_tagnames( $ns );

    # Then get the witnesses and create the witness objects.
    foreach my $wit_el ( $xpc->findnodes( "//$LISTWIT/$WITNESS" ) ) {
        my $sig = $wit_el->getAttribute( 'xml:id' );
        my $source = $wit_el->toString();
        $tradition->add_witness( sigil => $sig, source => $source );
    }

    map { $text->{$_->sigil} = [] } $tradition->witnesses;
    # Look for all word/seg node IDs and note their pre-existence.
    my @attrs = $xpc->findnodes( "//$W|$SEG/attribute::xml:id" );
    save_preexisting_nodeids( @attrs );

    # Now go through the children of the text element and pull out the
    # actual text.
    foreach my $xml_el ( $xpc->findnodes( "//$TEXT" ) ) {
        foreach my $xn ( $xml_el->childNodes ) {
            _get_readings( $tradition, $xn );
        }
    }
    # Our $text global now has lists of readings, one per witness.
    # Join them up.
    my $c = $tradition->collation;
    foreach my $sig ( keys %$text ) {
        next if $sig eq 'base';  # Skip base text readings with no witnesses.
        # Determine the list of readings for 
        my $sequence = $text->{$sig};
        my @real_sequence = ( $c->start );
        push( @$sequence, $c->end );
        my $source = $c->start;
        foreach( _clean_sequence( $sig, $sequence ) ) {
            my $rdg = _return_rdg( $_ );
            push( @real_sequence, $rdg );
            $c->add_path( $source, $rdg, $sig );
            $source = $rdg;
        }
        $tradition->witness( $sig )->path( \@real_sequence );
        # See if we need to make an a.c. version of the witness.
        if( exists $app_ac->{$sig} ) {
            my @uncorrected;
            push( @uncorrected, @real_sequence );
            foreach my $app ( keys %{$app_ac->{$sig}} ) {
                my $start = _return_rdg( $app_anchors->{$app}->{$sig}->{'start'} ); 
                my $end = _return_rdg( $app_anchors->{$app}->{$sig}->{'end'} );
                my @new = map { _return_rdg( $_ ) } @{$app_ac->{$sig}->{$app}};
                _replace_sequence( \@uncorrected, $start, $end, @new );
            }
            my $source = $c->start;
            foreach my $rdg ( @uncorrected ) {
                my $has_base = grep { $_->label eq $sig } $source->edges_to( $rdg );
                if( $rdg ne $c->start && !$has_base ) {
                    print STDERR sprintf( "Adding path %s from %s -> %s\n",
                        $sig.$c->ac_label, $source->name, $rdg->name );
                    $c->add_path( $source, $rdg, $sig.$c->ac_label );
                }
                $source = $rdg;
            }
            $tradition->witness( $sig )->uncorrected_path( \@uncorrected );
        }
    }
    # Delete readings that are no longer part of the graph.
    # TODO think this is useless actually
    foreach ( keys %$substitutions ) {
        $tradition->collation->del_reading( $tradition->collation->reading( $_ ) );
    }
    $tradition->collation->calculate_ranks();
}

sub _clean_sequence {
    my( $wit, $sequence ) = @_;
    my @clean_sequence;
    foreach my $rdg ( @$sequence ) {
        if( $rdg =~ /^PH-(.*)$/ ) {
            # It is a placeholder.  Keep it only if we need it.
            my $app_id = $1;
            if( exists $app_ac->{$wit}->{$app_id} ) {
                print STDERR "Retaining empty placeholder for $app_id\n";
                push( @clean_sequence, $rdg );
            }
        } else {
            push( @clean_sequence, $rdg );
        }
    }
    return @clean_sequence;
}

sub _replace_sequence {
    my( $arr, $start, $end, @new ) = @_;
    my( $start_idx, $end_idx );
    foreach my $i ( 0 .. $#{$arr} ) {
        $start_idx = $i if( $arr->[$i]->name eq $start );
        if( $arr->[$i]->name eq $end ) {
            $end_idx = $i;
            last;
        }
    }
    unless( $start_idx && $end_idx ) {
        warn "Could not find start and end";
        return;
    }
    my $length = $end_idx - $start_idx + 1;
    splice( @$arr, $start_idx, $length, @new );
}

sub _return_rdg {
    my( $rdg ) = @_;
    # If we were passed a reading name, return the name.  If we were
    # passed a reading object, return the object.
    my $wantobj = ref( $rdg ) eq 'Text::Tradition::Collation::Reading';
    my $real = $rdg;
    if( exists $substitutions->{ $wantobj ? $rdg->name : $rdg } ) {
        $real = $substitutions->{ $wantobj ? $rdg->name : $rdg };
        $real = $real->name unless $wantobj;
    }
    return $real;
}

## Recursive helper function to help us navigate through nested XML,
## picking out the text.  $tradition is the tradition, needed for
## making readings; $xn is the XML node currently being looked at,
## $in_var is a flag to say that we are inside a variant, $ac is a
## flag to say that we are inside an ante-correctionem reading, and
## @cur_wits is the list of witnesses to which this XML node applies.
## Returns the list of readings, if any, created on the run.

{
    my @active_wits;
    my $current_app;

    sub _get_readings {
        my( $tradition, $xn, $in_var, $ac, @cur_wits ) = @_;
        @cur_wits = @active_wits unless $in_var;

        my @new_readings;
        if( $xn->nodeType == XML_TEXT_NODE ) {
            # Some words, thus make some readings.
            my $str = $xn->data;
            return unless $str =~ /\S/; # skip whitespace-only text nodes
            #print STDERR "Handling text node " . $str . "\n";
            # Check that all the witnesses we have are active.
            foreach my $c ( @cur_wits ) {
                warn "Could not find $c in active wits"
                    unless grep { $c eq $_ } @active_wits;
            }
            $str =~ s/^\s+//;
            my $final = $str =~ s/\s+$//;
            foreach my $w ( split( /\s+/, $str ) ) {
                # For now, skip punctuation.
                next if $w !~ /[[:alnum:]]/;
                my $rdg = make_reading( $tradition->collation, $w );
                push( @new_readings, $rdg );
                unless( $in_var ) {
                    $rdg->make_common;
                }
                foreach ( @cur_wits ) {
                    warn "Empty wit!" unless $_;
                    warn "Empty reading!" unless $rdg;
                    push( @{$text->{$_}}, $rdg ) unless $ac;
                }
            }
        } elsif( $xn->nodeName eq 'w' ) {
            # Everything in this tag is one word.  Also save any original XML ID.
            #print STDERR "Handling word " . $xn->toString . "\n";
            # Check that all the witnesses we have are active.
            foreach my $c ( @cur_wits ) {
                warn "Could not find $c in active wits"
                    unless grep { $c eq $_ } @active_wits;
            }
            my $xml_id = $xn->getAttribute( 'xml:id' );
            my $rdg = make_reading( $tradition->collation, $xn->textContent, $xml_id );
            push( @new_readings, $rdg );
            unless( $in_var ) {
                $rdg->make_common;
            }
            foreach( @cur_wits ) {
                warn "Empty wit!" unless $_;
                warn "Empty reading!" unless $rdg;
                push( @{$text->{$_}}, $rdg ) unless $ac;
            }
        } elsif ( $xn->nodeName eq 'app' ) {
            $current_app = $xn->getAttribute( 'xml:id' );
            # print STDERR "Handling app $current_app\n";
            # Keep the reading sets in this app.
            my @sets;
            # Recurse through all children (i.e. rdgs) for sets of words.
            foreach ( $xn->childNodes ) {
                my @rdg_set = _get_readings( $tradition, $_, $in_var, $ac, @cur_wits );
                push( @sets, \@rdg_set ) if @rdg_set;
            }
            # Now collate these sets if we have more than one.
            my $subs = collate_variants( $tradition->collation, @sets ) if @sets > 1;
            map { $substitutions->{$_} = $subs->{$_} } keys %$subs;
            # TODO Look through substitutions to see if we can make anything common now.
            # Return the entire set of unique readings.
            my %unique;
            foreach my $s ( @sets ) {
                map { $unique{$_->name} = $_ } @$s;
            }
            push( @new_readings, values( %unique ) );
            # Exit the current app.
            $current_app = '';
        } elsif ( $xn->nodeName eq 'lem' || $xn->nodeName eq 'rdg' ) {
            # Alter the current witnesses and recurse.
            #print STDERR "Handling reading for " . $xn->getAttribute( 'wit' ) . "\n";
            $ac = $xn->getAttribute( 'type' ) && $xn->getAttribute( 'type' ) eq 'a.c.';
            my @rdg_wits = get_sigla( $xn );
            @rdg_wits = ( 'base' ) unless @rdg_wits;  # Allow for editorially-supplied readings
            my @words;
            foreach ( $xn->childNodes ) {
                my @rdg_set = _get_readings( $tradition, $_, 1, $ac, @rdg_wits );
                push( @words, @rdg_set ) if @rdg_set;
            }
            # If we have more than one word in a reading, it should become a segment.
            # $tradition->collation->add_segment( @words ) if @words > 1;
            
            if( $ac ) {
                # Add the reading set to the a.c. readings.
                foreach ( @rdg_wits ) {
                    $app_ac->{$_}->{$current_app} = \@words;
                }
            } else {
                # Add the reading set to the app anchors for each witness
                # or put in placeholders for empty p.c. readings
                foreach ( @rdg_wits ) {
                    my $start = @words ? $words[0]->name : "PH-$current_app";
                    my $end = @words ? $words[-1]->name : "PH-$current_app";
                    $app_anchors->{$current_app}->{$_}->{'start'} = $start;
                    $app_anchors->{$current_app}->{$_}->{'end'} = $end;
                    push( @{$text->{$_}}, $start ) unless @words;
                }
            }
            push( @new_readings, @words );
        } elsif( $xn->nodeName eq 'witStart' ) {
            # Add the relevant wit(s) to the active list.
            #print STDERR "Handling witStart\n";
            push( @active_wits, @cur_wits );
        } elsif( $xn->nodeName eq 'witEnd' ) {
            # Take the relevant wit(s) out of the list.
            #print STDERR "Handling witEnd\n";
            my $regexp = '^(' . join( '|', @cur_wits ) . ')$';
            @active_wits = grep { $_ !~ /$regexp/ } @active_wits;
        } elsif( $xn->nodeName eq 'witDetail' ) {
            # Ignore these for now.
            return;
        } else {
            # Recurse as if this tag weren't there.
            #print STDERR "Recursing on tag " . $xn->nodeName . "\n";
            foreach( $xn->childNodes ) {
                push( @new_readings, _get_readings( $tradition, $_, $in_var, $ac, @cur_wits ) );
            }
        }
        return @new_readings;
    }

}

# Helper to extract a list of witness sigla from a reading element.
sub get_sigla {
    my( $rdg ) = @_;
    # Cope if we have been handed a NodeList.  There is only
    # one reading here.
    if( ref( $rdg ) eq 'XML::LibXML::NodeList' ) {
        $rdg = $rdg->shift;
    }

    my @wits;
    if( ref( $rdg ) eq 'XML::LibXML::Element' ) {
        my $witstr = $rdg->getAttribute( 'wit' );
        $witstr =~ s/^\s+//;
        $witstr =~ s/\s+$//;
        @wits = split( /\s+/, $witstr );
        map { $_ =~ s/^\#// } @wits;
    }
    return @wits;
}

# Helper with its counters to actually make the readings.
{
    my $word_ctr = 0;
    my %used_nodeids;

    sub save_preexisting_nodeids {
        foreach( @_ ) {
            $used_nodeids{$_->getValue()} = 1;
        }
    }

    sub make_reading {
        my( $graph, $word, $xml_id ) = @_;
        if( $xml_id ) {
            if( exists $used_nodeids{$xml_id} ) {
                if( $used_nodeids{$xml_id} != 1 ) {
                    warn "Already used assigned XML ID somewhere else!";
                    $xml_id = undef;
                }
            } else {
                warn "Undetected pre-existing XML ID";
            }
        }
        if( !$xml_id ) {
            until( $xml_id ) {
                my $try_id = 'w'.$word_ctr++;
                next if exists $used_nodeids{$try_id};
                $xml_id = $try_id;
            }
        }
        my $rdg = $graph->add_reading( $xml_id );
        $rdg->text( $word );
        $used_nodeids{$xml_id} = $rdg;
        return $rdg;
    }
}

1;
Commit	Line	Data
f6066bac	1	package Text::Tradition::Parser::TEI;
	2
	3	use strict;
	4	use warnings;
910a0a6d	5	use Text::Tradition::Parser::Util qw( collate_variants );
f6066bac	6	use XML::LibXML;
	7	use XML::LibXML::XPathContext;
	8
	9	=head1 NAME
	10
	11	Text::Tradition::Parser::TEI
	12
	13	=head1 DESCRIPTION
	14
	15	Parser module for Text::Tradition, given a TEI parallel-segmentation
	16	file that describes a text and its variants.
	17
	18	=head1 METHODS
	19
	20	=over
	21
	22	=item B<parse>
	23
	24	parse( $tei_string );
	25
	26	Takes an initialized tradition and a string containing the TEI;
	27	creates the appropriate nodes and edges on the graph, as well as
	28	the appropriate witness objects.
	29
	30	=cut
	31
910a0a6d	32	my $text = {}; # Hash of arrays, one per eventual witness we find.
910a0a6d	33	my $substitutions = {}; # Keep track of merged readings
	34	my $app_anchors = {}; # Track apparatus references
	35	my $app_ac = {}; # Save a.c. readings
	36
	37	# Create the package variables for tag names.
	38
	39	# Would really like to do this with varname variables, but apparently this
	40	# is considered a bad idea. The long way round then.
	41	my( $LISTWIT, $WITNESS, $TEXT, $W, $SEG, $APP, $RDG, $LEM )
	42	= ( 'listWit', 'witness', 'text', 'w', 'seg', 'app', 'rdg', 'lem' );
	43	sub make_tagnames {
	44	my( $ns ) = @_;
	45	if( $ns ) {
	46	$LISTWIT = "$ns:$LISTWIT";
	47	$WITNESS = "$ns:$WITNESS";
	48	$TEXT = "$ns:$TEXT";
	49	$W = "$ns:$W";
	50	$SEG = "$ns:$SEG";
	51	$APP = "$ns:$APP";
	52	$RDG = "$ns:$RDG";
	53	$LEM = "$ns:$LEM";
	54	}
	55	}
	56
	57	# Parse the TEI file.
f6066bac	58	sub parse {
	59	my( $tradition, $xml_str ) = @_;
	60
	61	# First, parse the XML.
	62	my $parser = XML::LibXML->new();
	63	my $doc = $parser->parse_string( $xml_str );
	64	my $tei = $doc->documentElement();
f2b9605f	65	my $xpc = XML::LibXML::XPathContext->new( $tei );
910a0a6d	66	my $ns;
	67	if( $tei->namespaceURI ) {
	68	$ns = 'tei';
	69	$xpc->registerNs( $ns, $tei->namespaceURI );
	70	}
	71	make_tagnames( $ns );
	72
f6066bac	73	# Then get the witnesses and create the witness objects.
910a0a6d	74	foreach my $wit_el ( $xpc->findnodes( "//$LISTWIT/$WITNESS" ) ) {
	75	my $sig = $wit_el->getAttribute( 'xml:id' );
	76	my $source = $wit_el->toString();
	77	$tradition->add_witness( sigil => $sig, source => $source );
f6066bac	78	}
f6066bac	79
910a0a6d	80	map { $text->{$_->sigil} = [] } $tradition->witnesses;
	81	# Look for all word/seg node IDs and note their pre-existence.
	82	my @attrs = $xpc->findnodes( "//$W\|$SEG/attribute::xml:id" );
	83	save_preexisting_nodeids( @attrs );
	84
	85	# Now go through the children of the text element and pull out the
	86	# actual text.
	87	foreach my $xml_el ( $xpc->findnodes( "//$TEXT" ) ) {
	88	foreach my $xn ( $xml_el->childNodes ) {
	89	_get_readings( $tradition, $xn );
	90	}
	91	}
	92	# Our $text global now has lists of readings, one per witness.
	93	# Join them up.
	94	my $c = $tradition->collation;
	95	foreach my $sig ( keys %$text ) {
	96	next if $sig eq 'base'; # Skip base text readings with no witnesses.
	97	# Determine the list of readings for
	98	my $sequence = $text->{$sig};
	99	my @real_sequence = ( $c->start );
	100	push( @$sequence, $c->end );
	101	my $source = $c->start;
	102	foreach( _clean_sequence( $sig, $sequence ) ) {
	103	my $rdg = _return_rdg( $_ );
	104	push( @real_sequence, $rdg );
	105	$c->add_path( $source, $rdg, $sig );
	106	$source = $rdg;
	107	}
	108	$tradition->witness( $sig )->path( \@real_sequence );
	109	# See if we need to make an a.c. version of the witness.
	110	if( exists $app_ac->{$sig} ) {
	111	my @uncorrected;
	112	push( @uncorrected, @real_sequence );
	113	foreach my $app ( keys %{$app_ac->{$sig}} ) {
	114	my $start = _return_rdg( $app_anchors->{$app}->{$sig}->{'start'} );
	115	my $end = _return_rdg( $app_anchors->{$app}->{$sig}->{'end'} );
	116	my @new = map { _return_rdg( $_ ) } @{$app_ac->{$sig}->{$app}};
	117	_replace_sequence( \@uncorrected, $start, $end, @new );
	118	}
	119	my $source = $c->start;
	120	foreach my $rdg ( @uncorrected ) {
	121	my $has_base = grep { $_->label eq $sig } $source->edges_to( $rdg );
	122	if( $rdg ne $c->start && !$has_base ) {
	123	print STDERR sprintf( "Adding path %s from %s -> %s\n",
	124	$sig.$c->ac_label, $source->name, $rdg->name );
	125	$c->add_path( $source, $rdg, $sig.$c->ac_label );
	126	}
	127	$source = $rdg;
	128	}
	129	$tradition->witness( $sig )->uncorrected_path( \@uncorrected );
	130	}
	131	}
	132	# Delete readings that are no longer part of the graph.
	133	# TODO think this is useless actually
	134	foreach ( keys %$substitutions ) {
	135	$tradition->collation->del_reading( $tradition->collation->reading( $_ ) );
	136	}
7e450e44	137	$tradition->collation->calculate_ranks();
910a0a6d	138	}
	139
	140	sub _clean_sequence {
	141	my( $wit, $sequence ) = @_;
	142	my @clean_sequence;
	143	foreach my $rdg ( @$sequence ) {
	144	if( $rdg =~ /^PH-(.*)$/ ) {
	145	# It is a placeholder. Keep it only if we need it.
	146	my $app_id = $1;
	147	if( exists $app_ac->{$wit}->{$app_id} ) {
	148	print STDERR "Retaining empty placeholder for $app_id\n";
	149	push( @clean_sequence, $rdg );
	150	}
	151	} else {
	152	push( @clean_sequence, $rdg );
	153	}
f6066bac	154	}
910a0a6d	155	return @clean_sequence;
910a0a6d	156	}
f6066bac	157
910a0a6d	158	sub _replace_sequence {
	159	my( $arr, $start, $end, @new ) = @_;
	160	my( $start_idx, $end_idx );
	161	foreach my $i ( 0 .. $#{$arr} ) {
	162	$start_idx = $i if( $arr->[$i]->name eq $start );
	163	if( $arr->[$i]->name eq $end ) {
	164	$end_idx = $i;
	165	last;
	166	}
	167	}
	168	unless( $start_idx && $end_idx ) {
	169	warn "Could not find start and end";
	170	return;
f2b9605f	171	}
910a0a6d	172	my $length = $end_idx - $start_idx + 1;
	173	splice( @$arr, $start_idx, $length, @new );
	174	}
f6066bac	175
910a0a6d	176	sub _return_rdg {
	177	my( $rdg ) = @_;
	178	# If we were passed a reading name, return the name. If we were
	179	# passed a reading object, return the object.
	180	my $wantobj = ref( $rdg ) eq 'Text::Tradition::Collation::Reading';
	181	my $real = $rdg;
	182	if( exists $substitutions->{ $wantobj ? $rdg->name : $rdg } ) {
	183	$real = $substitutions->{ $wantobj ? $rdg->name : $rdg };
	184	$real = $real->name unless $wantobj;
	185	}
	186	return $real;
f6066bac	187	}
f6066bac	188
910a0a6d	189	## Recursive helper function to help us navigate through nested XML,
	190	## picking out the text. $tradition is the tradition, needed for
	191	## making readings; $xn is the XML node currently being looked at,
	192	## $in_var is a flag to say that we are inside a variant, $ac is a
	193	## flag to say that we are inside an ante-correctionem reading, and
	194	## @cur_wits is the list of witnesses to which this XML node applies.
	195	## Returns the list of readings, if any, created on the run.
	196
	197	{
	198	my @active_wits;
	199	my $current_app;
	200
	201	sub _get_readings {
	202	my( $tradition, $xn, $in_var, $ac, @cur_wits ) = @_;
	203	@cur_wits = @active_wits unless $in_var;
	204
	205	my @new_readings;
	206	if( $xn->nodeType == XML_TEXT_NODE ) {
	207	# Some words, thus make some readings.
	208	my $str = $xn->data;
	209	return unless $str =~ /\S/; # skip whitespace-only text nodes
	210	#print STDERR "Handling text node " . $str . "\n";
	211	# Check that all the witnesses we have are active.
	212	foreach my $c ( @cur_wits ) {
	213	warn "Could not find $c in active wits"
	214	unless grep { $c eq $_ } @active_wits;
	215	}
	216	$str =~ s/^\s+//;
	217	my $final = $str =~ s/\s+$//;
	218	foreach my $w ( split( /\s+/, $str ) ) {
	219	# For now, skip punctuation.
	220	next if $w !~ /[[:alnum:]]/;
	221	my $rdg = make_reading( $tradition->collation, $w );
	222	push( @new_readings, $rdg );
	223	unless( $in_var ) {
910a0a6d	224	$rdg->make_common;
	225	}
	226	foreach ( @cur_wits ) {
	227	warn "Empty wit!" unless $_;
	228	warn "Empty reading!" unless $rdg;
	229	push( @{$text->{$_}}, $rdg ) unless $ac;
	230	}
	231	}
	232	} elsif( $xn->nodeName eq 'w' ) {
	233	# Everything in this tag is one word. Also save any original XML ID.
	234	#print STDERR "Handling word " . $xn->toString . "\n";
	235	# Check that all the witnesses we have are active.
	236	foreach my $c ( @cur_wits ) {
	237	warn "Could not find $c in active wits"
	238	unless grep { $c eq $_ } @active_wits;
	239	}
	240	my $xml_id = $xn->getAttribute( 'xml:id' );
	241	my $rdg = make_reading( $tradition->collation, $xn->textContent, $xml_id );
	242	push( @new_readings, $rdg );
	243	unless( $in_var ) {
910a0a6d	244	$rdg->make_common;
	245	}
	246	foreach( @cur_wits ) {
	247	warn "Empty wit!" unless $_;
	248	warn "Empty reading!" unless $rdg;
	249	push( @{$text->{$_}}, $rdg ) unless $ac;
	250	}
	251	} elsif ( $xn->nodeName eq 'app' ) {
	252	$current_app = $xn->getAttribute( 'xml:id' );
	253	# print STDERR "Handling app $current_app\n";
	254	# Keep the reading sets in this app.
	255	my @sets;
	256	# Recurse through all children (i.e. rdgs) for sets of words.
	257	foreach ( $xn->childNodes ) {
	258	my @rdg_set = _get_readings( $tradition, $_, $in_var, $ac, @cur_wits );
	259	push( @sets, \@rdg_set ) if @rdg_set;
	260	}
	261	# Now collate these sets if we have more than one.
	262	my $subs = collate_variants( $tradition->collation, @sets ) if @sets > 1;
	263	map { $substitutions->{$_} = $subs->{$_} } keys %$subs;
	264	# TODO Look through substitutions to see if we can make anything common now.
	265	# Return the entire set of unique readings.
	266	my %unique;
	267	foreach my $s ( @sets ) {
	268	map { $unique{$_->name} = $_ } @$s;
	269	}
	270	push( @new_readings, values( %unique ) );
	271	# Exit the current app.
	272	$current_app = '';
	273	} elsif ( $xn->nodeName eq 'lem' \|\| $xn->nodeName eq 'rdg' ) {
	274	# Alter the current witnesses and recurse.
	275	#print STDERR "Handling reading for " . $xn->getAttribute( 'wit' ) . "\n";
	276	$ac = $xn->getAttribute( 'type' ) && $xn->getAttribute( 'type' ) eq 'a.c.';
	277	my @rdg_wits = get_sigla( $xn );
	278	@rdg_wits = ( 'base' ) unless @rdg_wits; # Allow for editorially-supplied readings
	279	my @words;
	280	foreach ( $xn->childNodes ) {
	281	my @rdg_set = _get_readings( $tradition, $_, 1, $ac, @rdg_wits );
	282	push( @words, @rdg_set ) if @rdg_set;
	283	}
	284	# If we have more than one word in a reading, it should become a segment.
	285	# $tradition->collation->add_segment( @words ) if @words > 1;
	286
	287	if( $ac ) {
	288	# Add the reading set to the a.c. readings.
	289	foreach ( @rdg_wits ) {
	290	$app_ac->{$_}->{$current_app} = \@words;
	291	}
	292	} else {
	293	# Add the reading set to the app anchors for each witness
	294	# or put in placeholders for empty p.c. readings
	295	foreach ( @rdg_wits ) {
	296	my $start = @words ? $words[0]->name : "PH-$current_app";
	297	my $end = @words ? $words[-1]->name : "PH-$current_app";
	298	$app_anchors->{$current_app}->{$_}->{'start'} = $start;
	299	$app_anchors->{$current_app}->{$_}->{'end'} = $end;
	300	push( @{$text->{$_}}, $start ) unless @words;
	301	}
	302	}
	303	push( @new_readings, @words );
	304	} elsif( $xn->nodeName eq 'witStart' ) {
	305	# Add the relevant wit(s) to the active list.
	306	#print STDERR "Handling witStart\n";
	307	push( @active_wits, @cur_wits );
308	} elsif( $xn->nodeName eq 'witEnd' ) {
309	# Take the relevant wit(s) out of the list.
310	#print STDERR "Handling witEnd\n";
311	my $regexp = '^(' . join( '\|', @cur_wits ) . ')$';
312	@active_wits = grep { $_ !~ /$regexp/ } @active_wits;
313	} elsif( $xn->nodeName eq 'witDetail' ) {
314	# Ignore these for now.
315	return;
316	} else {
317	# Recurse as if this tag weren't there.
318	#print STDERR "Recursing on tag " . $xn->nodeName . "\n";
319	foreach( $xn->childNodes ) {
320	push( @new_readings, _get_readings( $tradition, $_, $in_var, $ac, @cur_wits ) );
321	}
322	}
323	return @new_readings;
324	}
325
326	}
327
328	# Helper to extract a list of witness sigla from a reading element.
f6066bac	329	sub get_sigla {
	330	my( $rdg ) = @_;
	331	# Cope if we have been handed a NodeList. There is only
	332	# one reading here.
	333	if( ref( $rdg ) eq 'XML::LibXML::NodeList' ) {
910a0a6d	334	$rdg = $rdg->shift;
f6066bac	335	}
	336
	337	my @wits;
	338	if( ref( $rdg ) eq 'XML::LibXML::Element' ) {
910a0a6d	339	my $witstr = $rdg->getAttribute( 'wit' );
	340	$witstr =~ s/^\s+//;
	341	$witstr =~ s/\s+$//;
	342	@wits = split( /\s+/, $witstr );
	343	map { $_ =~ s/^\#// } @wits;
f6066bac	344	}
	345	return @wits;
	346	}
	347
910a0a6d	348	# Helper with its counters to actually make the readings.
f2b9605f	349	{
	350	my $word_ctr = 0;
	351	my %used_nodeids;
	352
910a0a6d	353	sub save_preexisting_nodeids {
	354	foreach( @_ ) {
	355	$used_nodeids{$_->getValue()} = 1;
	356	}
	357	}
	358
f2b9605f	359	sub make_reading {
910a0a6d	360	my( $graph, $word, $xml_id ) = @_;
	361	if( $xml_id ) {
	362	if( exists $used_nodeids{$xml_id} ) {
	363	if( $used_nodeids{$xml_id} != 1 ) {
	364	warn "Already used assigned XML ID somewhere else!";
	365	$xml_id = undef;
	366	}
	367	} else {
	368	warn "Undetected pre-existing XML ID";
	369	}
	370	}
	371	if( !$xml_id ) {
	372	until( $xml_id ) {
	373	my $try_id = 'w'.$word_ctr++;
	374	next if exists $used_nodeids{$try_id};
	375	$xml_id = $try_id;
	376	}
	377	}
	378	my $rdg = $graph->add_reading( $xml_id );
	379	$rdg->text( $word );
	380	$used_nodeids{$xml_id} = $rdg;
	381	return $rdg;
f2b9605f	382	}
	383	}
	384
f6066bac	385	1;