add morphology support for Latin, dependent on Perseus morphology

[scpubgit/stemmatology.git] / lib / Text / Tradition / Language / Latin.pm

diff --git a/lib/Text/Tradition/Language/Latin.pm b/lib/Text/Tradition/Language/Latin.pm
new file mode 100644 (file)
index 0000000..07dc611
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+++ b/lib/Text/Tradition/Language/Latin.pm
@@ -0,0 +1,158 @@
+package Text::Tradition::Language::Latin;
+
+use strict;
+use warnings;
+use Module::Load;
+use Text::Tradition::Language::Base qw/ lemmatize_treetagger treetagger_struct /;
+use TryCatch;
+
+=head1 NAME
+
+Text::Tradition::Language::Latin - language-specific module for Latin
+
+=head1 DESCRIPTION
+
+Implements morphology lookup for French words in context.  This module
+depends on the Morph::Perseus module for access to PhiloLogic database data.
+It also depends on the TreeTagger software
+(L<http://www.ims.uni-stuttgart.de/projekte/corplex/TreeTagger/>), which is
+(for now) expected to be installed in $MORPHDIR/TreeTagger.
+
+=head1 SUBROUTINES
+
+=head2 lemmatize( $text )
+
+Evaluates the string using the Flemm package, and returns the results.
+
+=begin testing
+
+use Text::Tradition;
+use_ok( 'Text::Tradition::Language::Latin' );
+
+eval "use Morph::Perseus";
+my $err = $@;
+
+SKIP: {
+       skip "Package Morph::Perseus not found" if $err;
+
+       my $trad = Text::Tradition->new(
+               'language' => 'Latin',
+               'file' => 't/data/legendfrag.xml',
+               'input' => 'Self' );
+       $trad->lemmatize();
+       my $ambig = 0;
+       foreach my $r ( $trad->collation->readings ) {
+               next if $r->is_meta;
+               ok( $r->has_lexemes, "Reading $r has one or more lexemes" );
+               my @lex = $r->lexemes;
+               my $lexstr = join( '', map { $_->string } @lex );
+               my $textstr = $r->text;
+               $textstr =~ s/\s+//g;
+               is( $textstr, $lexstr, "Lexemes for reading $r match the reading" );
+               foreach my $l ( @lex ) {
+                       next if $l->is_disambiguated;
+                       printf( "Ambiguous lexeme %s for reading %s:\n\t%s\n", $l->string, $r->id,
+                               join( "\n\t", map { $_->lemma . ': ' . $_->morphology->to_string } $l->matching_forms ) );
+                       $ambig++;
+               }
+       }
+       is( $ambig, 19, "Found 19 ambiguous forms as expected" );
+}
+
+=end testing
+
+=cut
+
+sub lemmatize {
+       my $tradition = shift;
+       my %opts = ( 
+               'language' => 'Latin', 
+               'callback' => sub { _perseus_lookup_tt( @_ ) } 
+               );
+       return lemmatize_treetagger( $tradition, %opts );
+}
+
+=head2 reading_lookup( $rdg[, $rdg, ...] )
+
+Looks up one or more readings using the Perseus package, and returns the
+possible results.  This skips the tree tagger / tokenizer, returning any
+match for the word string(s) in the morphology DB.
+
+=cut
+
+sub reading_lookup {
+       my @words = @_;
+       return map { _perseus_lookup_str( $_ ) } @words;
+}
+
+{
+       my $morph;
+       
+       sub _morph_connect {
+               unless( $morph ) {
+                       try {
+                               load 'Morph::Perseus';
+                               load 'Morph::Perseus::Structure';
+                               $morph = Morph::Perseus->connect( 'Latin' );
+                       } catch {
+                               warn "Cannot do Latin word lemmatization without Morph::Perseus: @_";
+                               return;
+                       }
+               }
+       }
+               
+       sub _perseus_lookup_tt {
+               my( $orig, $pos, $lemma ) = split( /\t/, $_[0] );
+               _morph_connect();
+               my $result = $morph->lookup( $orig );
+               # Discard results that don't match the lemma, unless lemma is unknown
+               my @ret;
+               unless( $lemma eq '<unknown>' ) {
+                       # TODO Perseus lemma might have a number on the end, yuck.
+                       @ret = grep { $_->lemma =~ /^$lemma(\d*)$/ } @{$result->{'objects'}};
+               }
+               unless( @ret ) {
+                       @ret = @{$result->{'objects'}};
+                       warn "TreeTagger lemma $lemma matched no results from Perseus for $orig"
+                               if @ret;
+               }
+               
+               # Discard results that don't match the given TreeTagger POS, unless
+               # that leaves zero results
+               my @wordforms;
+               foreach my $obj ( @ret ) {
+                       push( @wordforms, _wordform_from_row( $obj ) );
+               }
+               ## TODO Use TreeTagger info - requires serious hacking of Lingua::TagSet
+#              my $ttstruct = treetagger_struct( $pos );
+#              my @ttmatch = grep { $ttstruct->is_compatible( $_->morphology ) } @wordforms;
+#              unless( @ttmatch ) {
+#                      warn "TreeTagger POS $pos matched no results from Perseus for $orig";
+#                      @ttmatch = @wordforms;
+#              }
+#              return @ttmatch;
+               return @wordforms;
+       }
+       
+       sub _perseus_lookup_str {
+               my( $orig ) = @_;
+               _morph_connect();
+               # Simple morph DB lookup, and return the results.
+               my $result = $morph->lookup( $orig );
+               return map { _wordform_from_row( $_ ) } @{$result->{'objects'}};
+       }
+       
+       sub _wordform_from_row {
+               my( $rowobj ) = @_;
+               my $mpstruct = Morph::Perseus::Structure->from_tag( $rowobj->code );
+               my $wf = Text::Tradition::Collation::Reading::WordForm->new(
+                       'language' => 'Latin',
+                       'lemma' => $rowobj->lemma,
+                       'morphology' => $mpstruct,
+                       );
+               return $wf;
+       }
+       
+}
+
+1;
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