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NAME

Lingua::StanfordCoreNLP - A Perl interface to Stanford's CoreNLP tool set.

SYNOPSIS

# Note that Lingua::StanfordCoreNLP can't be instantiated.
use Lingua::StanfordCoreNLP;

# Create a new NLP pipeline (make corefs bidirectional)
my $pipeline = new Lingua::StanfordCoreNLP::Pipeline(1);

# Get annotator properties:
my $props = $pipeline->getProperties();

# These are the default annotator properties:
$props->put('annotators', 'tokenize, ssplit, pos, lemma, ner, parse, dcoref');

# Update properties:
$pipeline->setProperties($props);

# Process text
# (Will output lots of debug info from the Java classes to STDERR.)
my $result = $pipeline->process(
   'Jane looked at the IBM computer. She turned it off.'
);

my @seen_corefs;

# Print results
for my $sentence (@{$result->toArray}) {
   print "\n[Sentence ID: ", $sentence->getIDString, "]:\n";
   print "Original sentence:\n\t", $sentence->getSentence, "\n";

   print "Tagged text:\n";
   for my $token (@{$sentence->getTokens->toArray}) {
      printf "\t%s/%s/%s [%s]\n",
             $token->getWord,
             $token->getPOSTag,
             $token->getNERTag,
             $token->getLemma;
   }

   print "Dependencies:\n";
   for my $dep (@{$sentence->getDependencies->toArray}) {
      printf "\t%s(%s-%d, %s-%d) [%s]\n",
             $dep->getRelation,
             $dep->getGovernor->getWord,
             $dep->getGovernorIndex,
             $dep->getDependent->getWord,
             $dep->getDependentIndex,
             $dep->getLongRelation;
   }

   print "Coreferences:\n";
   for my $coref (@{$sentence->getCoreferences->toArray}) {
      printf "\t%s [%d, %d] <=> %s [%d, %d]\n",
             $coref->getSourceToken->getWord,
             $coref->getSourceSentence,
             $coref->getSourceHead,
             $coref->getTargetToken->getWord,
             $coref->getTargetSentence,
             $coref->getTargetHead;

      print "\t\t(Duplicate)\n"
         if(grep { $_->equals($coref) } @seen_corefs);

      push @seen_corefs, $coref;
   }
}

DESCRIPTION

This module implements a StanfordCoreNLP pipeline for annotating text with part-of-speech tags, dependencies, lemmas, named-entity tags, and coreferences.

(Note that the archive contains the CoreNLP annotation models, which is why it's so darn big. Also note that versions before 0.10 have slightly different API:s than 0.10+.)

INSTALLATION

The following should do the job:

$ perl Build.PL
$ ./Build test
$ sudo ./Build install

PREREQUISITES

Lingua::StanfordCoreNLP consists mainly of Java code, and thus needs Inline::Java installed to function.

ENVIRONMENT

Lingua::StanfordCoreNLP can use the following environmental variables

LINGUA_CORENLP_JAR_PATH

Directory containing the CoreNLP jar-files. Normally, Lingua::StanfordCoreNLP expects LINGUA_CORENLP_JAR_PATH to contain the following files:

stanford-corenlp-VERSION.jar
stanford-corenlp-VERSION-models.jar
joda-time.jar
jollyday.jar
xom.jar

(Where VERSION is 1.3.4 or the value of LINGUA_CORENLP_VERSION.) If your filenames are different, you can add *.jar to the end of the path, to make Lingua::StanfordCoreNLP use all the jar-files in LINGUA_CORENLP_JAR_PATH.

LINGUA_CORENLP_VERSION

Version of jar-files in LINGUA_CORENLP_JAR_PATH.

LINGUA_CORENLP_JAVA_ARGS

Arguments to pass to JVM (via Inline::Java). Defaults to -Xmx2000m (increase max memory to 2000 MB).

EXPORTED CLASS

Lingua::StanfordCoreNLP exports the following Java-classes via Inline::Java:

Lingua::StanfordCoreNLP::Pipeline

The main interface to StanfordCoreNLP. This class is the only one you can instantiate yourself. It is, basically, a perlified be.fivebyfive.lingua.stanfordcorenlp.Pipeline.

new
new($bidirectionalCorefs)

Creates a new Lingua::StanfordCoreNLP::Pipeline object. The optional boolean parameter $bidirectionalCorefs makes coreferences bidirectional; that is to say, the coreference is added to both the source and the target sentence of all coreferences (if the source and target sentence are different). $silent and $bidirectionalCorefs default to false.

getProperties

Returns a java.util.Properties object containing annotator options. By default it contains a single entry, "annotators", which has the value "tokenize, ssplit, pos, lemma, ner, parse, dcoref".

setProperties($prop)

Updates annotator options. Expects a java.util.Properties object. If you call this after having called process, you will have to call initPipeline to update the annotator.

getPipeline

Returns a reference to the StanfordCoreNLP pipeline used for annotation. You probably won't want to touch this.

initPipeline

Reinitializes the StanfordCoreNLP pipeline used for annotation.

process($str)

Process a string. Returns a Lingua::StanfordCoreNLP::PipelineSentenceList.

JAVA CLASSES

In addition, Lingua::StanfordCoreNLP indirectly exports the following Java-classes, all belonging to the namespace be.fivebyfive.lingua.stanfordcorenlp:

PipelineItem

Abstract superclass of Pipeline{Coreference,Dependency,Sentence,Token}. Contains ID and methods for getting and comparing it.

getID

Returns a java.util.UUID object which represents the item's ID.

getIDString

Returns the ID as a string.

identicalTo($b)

Returns true if $b has an identical ID to this item.

PipelineCoreference

An object representing a coreference between head-word W1 in sentence S1 and head-word W2 in sentence S2. Note that both sentences and words are zero-indexed, unlike the default outputs of Stanford's tools.

getSourceSentence

Index of sentence S1.

getTargetSentence

Index of sentence S2.

getSourceHead

Index of word W1 (in S1).

getTargetHead

Index of word W2 (in S2).

getSourceToken

The PipelineToken representing W1.

getTargetToken

The PipelineToken representing W2.

equals($b)

Returns true if this PipelineCoreference matches $b --- if their getSourceToken and getTargetToken have the same ID. Note that it returns true even if the orders of the coreferences are reversed (if $a->getSourceToken->getID == $b->getTargetToken->getID and $a->getTargetToken->getID == $b->getSourceToken->getID).

toCompactString

A compact String representation of the coreference --- "Word/Sentence:Head <=> Word/Sentence:Head".

toString

A String representation of the coreference --- "Word/POS-tag [sentence, head] <=> Word/POS-tag [sentence, head]".

PipelineDependency

Represents a dependency in the Stanford Typed Dependency format. For example, in the fragment "Walk hard", "Walk" is the governor and "hard" is the dependent in the relationship "advmod" ("hard" is an adverbial modifier of "Walk").

getGovernor

The governor in the relation as a PipelineToken.

getGovernorIndex

The index of the governor within the sentence.

getDependent

The dependent in the relation as a PipelineToken.

getDependentIndex

The index of the dependent within the sentence.

getRelation

Short name of the relation.

getLongRelation

Long description of the relation.

toCompactString
toCompactString($includeIndices)
toString
toString($includeIndices)

Returns a String representation of the dependency --- "relation(governor-N, dependent-N) [description]". toCompactString does not include description. The optional parameter $includeIndices controls whether governor and dependent indices are included, and defaults to true. (Note that unlike those of, e.g., the Stanford Parser, these indices start at zero, not one.)

PipelineSentence

An annotated sentence, containing the sentence itself, its dependencies, pos- and ner-tagged tokens, and coreferences.

getSentence

Returns a string containing the original sentence

getTokens

A PipelineTokenList containing the POS- and NER-tagged and lemmaized tokens of the sentence.

getDependencies

A PipelineDependencyList containing the dependencies found in the sentence.

getCoreferences

A PipelineCoreferenceList of the coreferences between this and other sentences.

toCompactString
toString

A String representation of the sentence, its coreferences, dependencies, and tokens. toCompactString separates fields by "\n", whereas toString separates them by "\n\n".

PipelineToken

A token, with POS- and NER-tag and lemma.

getWord

The textual representation of the token (i.e. the word).

getPOSTag

The token's Part-of-Speech tag.

getNERTag

The token's Named-Entity tag.

getLemma

The lemma of the the token.

toCompactString
toCompactString($lemmaize)

A compact String representation of the token --- "word/POS-tag". If the optional argument $lemmaize is true, returns "lemma/POS-tag".

toString

A String representation of the token --- "word/POS-tag/NER-tag [lemma]".

PipelineList

PipelineCoreferenceList

PipelineDependencyList

PipelineSentenceList

PipelineTokenList

PipelineList is a generic list class which extends java.Util.ArrayList. It is in turn extended by Pipeline{Coreference,Dependency,Sentence,Token}List (which are the list-types that Pipeline returns). Note that all lists are zero-indexed.

joinList($sep)
joinListCompact($sep)

Returns a string containing the output of either the toString or toCompactString methods of the elements in PipelineList, separated by $sep.

toArray

Return the elements of the list as an array-reference.

toHashMap

Return the list as a java.util.HashMap<String,PipelineItem>, with items' stringified ID:s as keys.

toCompactString
toString

Returns the elements of the PipelineList as a string containing the output of either their toCompactString or toString methods, separated by the default separator (which is "\n" for all lists except PipelineTokenList which uses " ").

TODO

  • Add representative mention to PipelineCoreference.

  • Make build system also compile LinguaSCNLP.jar.

REQUESTS & BUGS

Please file any issues, bug-reports, or feature-requests at https://github.com/raisanen/lingua-stanfordcorenlp.

AUTHORS

Kalle Räisänen <kal@cpan.org>.

COPYRIGHT

Lingua::StanfordCoreNLP (Perl bindings)

Copyright © 2011-2013 Kalle Räisänen.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Stanford CoreNLP tool set

Copyright © 2010-2012 The Board of Trustees of The Leland Stanford Junior University.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, see http://www.gnu.org/licenses/.

SEE ALSO

http://nlp.stanford.edu/software/corenlp.shtml, Text::NLP::Stanford::EntityExtract, NLP::StanfordParser, Inline::Java.