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Stanford CoreNLP provides a set of natural language analysis tools which can take raw English language text input and give the base forms of words, their parts of speech, whether they are names of companies, people, etc., normalize dates, times, and numeric quantities, mark up the structure of sentences in terms of phrases and word dependencies, and indicate which noun phrases refer to the same entities. It provides the foundational building blocks for higher level text understanding applications.
// TregexPatternCompiler
// Copyright (c) 2004-2007 The Board of Trustees of
// The Leland Stanford Junior University. All Rights Reserved.
//
// 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, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
//
// For more information, bug reports, fixes, contact:
// Christopher Manning
// Dept of Computer Science, Gates 1A
// Stanford CA 94305-9010
// USA
// Support/Questions: [email protected]
// Licensing: [email protected]
// http://www-nlp.stanford.edu/software/tregex.shtml
package edu.stanford.nlp.trees.tregex;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Function;
import edu.stanford.nlp.util.Pair;
import edu.stanford.nlp.trees.CollinsHeadFinder;
import edu.stanford.nlp.trees.HeadFinder;
import edu.stanford.nlp.trees.PennTreebankLanguagePack;
/**
* A class for compiling TregexPatterns with specific HeadFinders and or
* basicCategoryFunctions.
*
* @author Galen Andrew
*/
public class TregexPatternCompiler {
static final Function DEFAULT_BASIC_CAT_FUNCTION =
new PennTreebankLanguagePack().getBasicCategoryFunction();
static final HeadFinder DEFAULT_HEAD_FINDER = new CollinsHeadFinder();
private final Function basicCatFunction;
private final HeadFinder headFinder;
private final List> macros =
new ArrayList<>();
public static final TregexPatternCompiler defaultCompiler =
new TregexPatternCompiler();
public TregexPatternCompiler() {
this(DEFAULT_HEAD_FINDER, DEFAULT_BASIC_CAT_FUNCTION);
}
/**
* A compiler that uses this basicCatFunction and the default HeadFinder.
*
* @param basicCatFunction the function mapping Strings to Strings
*/
public TregexPatternCompiler(Function basicCatFunction) {
this(DEFAULT_HEAD_FINDER, basicCatFunction);
}
/**
* A compiler that uses this HeadFinder and the default basicCategoryFunction
*
* @param headFinder the HeadFinder
*/
public TregexPatternCompiler(HeadFinder headFinder) {
this(headFinder, DEFAULT_BASIC_CAT_FUNCTION);
}
/**
* A compiler that uses this HeadFinder and this basicCategoryFunction
*
* @param headFinder the HeadFinder
* @param basicCatFunction The function mapping Strings to Strings
*/
public TregexPatternCompiler(HeadFinder headFinder,
Function basicCatFunction) {
this.headFinder = headFinder;
this.basicCatFunction = basicCatFunction;
}
// todo [cdm 2013]: Provide an easy way to do Matcher.quoteReplacement(): This would be quite useful, since the replacement will often contain $ or \
/** Define a macro for rewriting a pattern in any tregex expression compiled
* by this compiler. The semantics of this is that all instances of the
* original in the pattern are replaced by the replacement, using exactly
* the semantics of String.replaceAll(original, replacement) and the
* result will then be compiled by the compiler. As such, note that a
* macro can replace any part of a tregex expression, in a syntax
* insensitive way. Here's an example:
* {@code tpc.addMacro("FINITE_BE_AUX", "/^(?i:am|is|are|was|were)$/");}
*
* @param original The String to match; becomes the first argument of a
* String.replaceAll()
* @param replacement The replacement String; becomes the second argument
* of a String.replaceAll()
*/
public void addMacro(String original, String replacement) {
macros.add(new Pair<>(original, replacement));
}
/**
* Create a TregexPattern from this tregex string using the headFinder and
* basicCat function this TregexPatternCompiler was created with.
*
* Implementation note: If there is an invalid token in the Tregex
* parser, JavaCC will throw a TokenMgrError. This is a class
* that extends Error, not Exception (OMG! - bad!), and so rather than
* requiring clients to catch it, we wrap it in a ParseException.
* (The original Error's are thrown in TregexParserTokenManager.)
*
* @param tregex The pattern to parse
* @return A new TregexPattern object based on this string
* @throws TregexParseException If the expression is syntactically invalid
*/
public TregexPattern compile(String tregex) {
for (Pair macro : macros) {
tregex = tregex.replaceAll(macro.first(), macro.second());
}
TregexPattern pattern;
try {
TregexParser parser = new TregexParser(new StringReader(tregex + '\n'),
basicCatFunction, headFinder);
pattern = parser.Root();
} catch (TokenMgrError tme) {
throw new TregexParseException("Could not parse " + tregex, tme);
} catch (ParseException e) {
throw new TregexParseException("Could not parse " + tregex, e);
}
pattern.setPatternString(tregex);
return pattern;
}
}