Google Git
Sign in
apache / opennlp-site / asf-site / . / docs / 2.5.6 / apidocs / opennlp-tools / opennlp / tools / stemmer / PorterStemmer.html
blob: 8ab4a9b036185c8897d158d00829e90533800ef5 [file] [log] [blame]
<!DOCTYPE HTML>
<html lang>
<head>
<!-- Generated by javadoc (17) -->
<title>PorterStemmer (Apache OpenNLP Tools 2.5.6 API)</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="description" content="declaration: package: opennlp.tools.stemmer, class: PorterStemmer">
<meta name="generator" content="javadoc/ClassWriterImpl">
<link rel="stylesheet" type="text/css" href="../../../stylesheet.css" title="Style">
<link rel="stylesheet" type="text/css" href="../../../script-dir/jquery-ui.min.css" title="Style">
<link rel="stylesheet" type="text/css" href="../../../jquery-ui.overrides.css" title="Style">
<script type="text/javascript" src="../../../script.js"></script>
<script type="text/javascript" src="../../../script-dir/jquery-3.7.1.min.js"></script>
<script type="text/javascript" src="../../../script-dir/jquery-ui.min.js"></script>
</head>
<body class="class-declaration-page">
<script type="text/javascript">var evenRowColor = "even-row-color";
var oddRowColor = "odd-row-color";
var tableTab = "table-tab";
var activeTableTab = "active-table-tab";
var pathtoroot = "../../../";
loadScripts(document, 'script');</script>
<noscript>
<div>JavaScript is disabled on your browser.</div>
</noscript>
<div class="flex-box">
<header role="banner" class="flex-header">
<nav role="navigation">
<!-- ========= START OF TOP NAVBAR ======= -->
<div class="top-nav" id="navbar-top">
<div class="skip-nav"><a href="#skip-navbar-top" title="Skip navigation links">Skip navigation links</a></div>
<ul id="navbar-top-firstrow" class="nav-list" title="Navigation">
<li><a href="../../../index.html">Overview</a></li>
<li><a href="package-summary.html">Package</a></li>
<li class="nav-bar-cell1-rev">Class</li>
<li><a href="package-tree.html">Tree</a></li>
<li><a href="../../../deprecated-list.html">Deprecated</a></li>
<li><a href="../../../index-all.html">Index</a></li>
<li><a href="../../../help-doc.html#class">Help</a></li>
</ul>
</div>
<div class="sub-nav">
<div>
<ul class="sub-nav-list">
<li>Summary:&nbsp;</li>
<li>Nested&nbsp;|&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor-summary">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method-summary">Method</a></li>
</ul>
<ul class="sub-nav-list">
<li>Detail:&nbsp;</li>
<li>Field&nbsp;|&nbsp;</li>
<li><a href="#constructor-detail">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method-detail">Method</a></li>
</ul>
</div>
<div class="nav-list-search"><label for="search-input">SEARCH:</label>
<input type="text" id="search-input" value="search" disabled="disabled">
<input type="reset" id="reset-button" value="reset" disabled="disabled">
</div>
</div>
<!-- ========= END OF TOP NAVBAR ========= -->
<span class="skip-nav" id="skip-navbar-top"></span></nav>
</header>
<div class="flex-content">
<main role="main">
<!-- ======== START OF CLASS DATA ======== -->
<div class="header">
<div class="sub-title"><span class="package-label-in-type">Package</span>&nbsp;<a href="package-summary.html">opennlp.tools.stemmer</a></div>
<h1 title="Class PorterStemmer" class="title">Class PorterStemmer</h1>
</div>
<div class="inheritance" title="Inheritance Tree"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">java.lang.Object</a>
<div class="inheritance">opennlp.tools.stemmer.PorterStemmer</div>
</div>
<section class="class-description" id="class-description">
<dl class="notes">
<dt>All Implemented Interfaces:</dt>
<dd><code><a href="Stemmer.html" title="interface in opennlp.tools.stemmer">Stemmer</a></code></dd>
</dl>
<hr>
<div class="type-signature"><span class="modifiers">public class </span><span class="element-name type-name-label">PorterStemmer</span>
<span class="extends-implements">extends <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">Object</a>
implements <a href="Stemmer.html" title="interface in opennlp.tools.stemmer">Stemmer</a></span></div>
<div class="block">A <a href="Stemmer.html" title="interface in opennlp.tools.stemmer"><code>Stemmer</code></a>, implementing the <a href="https://tartarus.org/martin/PorterStemmer/">
Porter Stemming Algorithm</a>
<p>
The Stemmer implementation transforms a word into its root form. The input
word can be provided a character at time (by calling <a href="#add(char)"><code>add(char)</code></a>),
or at once by calling one of the various <code>stem(..)</code> methods.</div>
</section>
<section class="summary">
<ul class="summary-list">
<!-- ======== CONSTRUCTOR SUMMARY ======== -->
<li>
<section class="constructor-summary" id="constructor-summary">
<h2>Constructor Summary</h2>
<div class="caption"><span>Constructors</span></div>
<div class="summary-table two-column-summary">
<div class="table-header col-first">Constructor</div>
<div class="table-header col-last">Description</div>
<div class="col-constructor-name even-row-color"><code><a href="#%3Cinit%3E()" class="member-name-link">PorterStemmer</a>()</code></div>
<div class="col-last even-row-color">&nbsp;</div>
</div>
</section>
</li>
<!-- ========== METHOD SUMMARY =========== -->
<li>
<section class="method-summary" id="method-summary">
<h2>Method Summary</h2>
<div id="method-summary-table">
<div class="table-tabs" role="tablist" aria-orientation="horizontal"><button id="method-summary-table-tab0" role="tab" aria-selected="true" aria-controls="method-summary-table.tabpanel" tabindex="0" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table', 3)" class="active-table-tab">All Methods</button><button id="method-summary-table-tab2" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab2', 3)" class="table-tab">Instance Methods</button><button id="method-summary-table-tab4" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab4', 3)" class="table-tab">Concrete Methods</button></div>
<div id="method-summary-table.tabpanel" role="tabpanel" aria-labelledby="method-summary-table-tab0">
<div class="summary-table three-column-summary">
<div class="table-header col-first">Modifier and Type</div>
<div class="table-header col-second">Method</div>
<div class="table-header col-last">Description</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>void</code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#add(char)" class="member-name-link">add</a><wbr>(char&nbsp;ch)</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Add a character to the word being stemmed.</div>
</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>char[]</code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#getResultBuffer()" class="member-name-link">getResultBuffer</a>()</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Returns a reference to a character buffer containing the results of
the stemming process.</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>int</code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#getResultLength()" class="member-name-link">getResultLength</a>()</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Returns the length of the word resulting from the stemming process.</div>
</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>void</code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#reset()" class="member-name-link">reset</a>()</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">reset() resets the stemmer so it can stem another word.</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>boolean</code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem()" class="member-name-link">stem</a>()</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem the word placed into the Stemmer buffer through calls to add().</div>
</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>boolean</code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(char%5B%5D)" class="member-name-link">stem</a><wbr>(char[]&nbsp;word)</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem a word contained in a char[].</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>boolean</code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(char%5B%5D,int)" class="member-name-link">stem</a><wbr>(char[]&nbsp;word,
int&nbsp;wordLen)</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem a word contained in a leading portion of a char[] array.</div>
</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>boolean</code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(char%5B%5D,int,int)" class="member-name-link">stem</a><wbr>(char[]&nbsp;wordBuffer,
int&nbsp;offset,
int&nbsp;wordLen)</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem a word contained in a portion of a char[] array.</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>boolean</code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(int)" class="member-name-link">stem</a><wbr>(int&nbsp;i0)</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">&nbsp;</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/CharSequence.html" title="class or interface in java.lang" class="external-link">CharSequence</a></code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(java.lang.CharSequence)" class="member-name-link">stem</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/CharSequence.html" title="class or interface in java.lang" class="external-link">CharSequence</a>&nbsp;word)</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem a word provided as a CharSequence.</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></code></div>
<div class="col-second even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#stem(java.lang.String)" class="member-name-link">stem</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;s)</code></div>
<div class="col-last even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">Stem a word provided as a String.</div>
</div>
<div class="col-first odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></code></div>
<div class="col-second odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code><a href="#toString()" class="member-name-link">toString</a>()</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<div class="block">After a word has been stemmed, it can be retrieved by toString(),
or a reference to the internal buffer can be retrieved by getResultBuffer
and getResultLength (which is generally more efficient.)</div>
</div>
</div>
</div>
</div>
<div class="inherited-list">
<h3 id="methods-inherited-from-class-java.lang.Object">Methods inherited from class&nbsp;java.lang.<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">Object</a></h3>
<code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#equals(java.lang.Object)" title="class or interface in java.lang" class="external-link">equals</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#getClass()" title="class or interface in java.lang" class="external-link">getClass</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#hashCode()" title="class or interface in java.lang" class="external-link">hashCode</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#notify()" title="class or interface in java.lang" class="external-link">notify</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#notifyAll()" title="class or interface in java.lang" class="external-link">notifyAll</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#wait()" title="class or interface in java.lang" class="external-link">wait</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#wait(long)" title="class or interface in java.lang" class="external-link">wait</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#wait(long,int)" title="class or interface in java.lang" class="external-link">wait</a></code></div>
</section>
</li>
</ul>
</section>
<section class="details">
<ul class="details-list">
<!-- ========= CONSTRUCTOR DETAIL ======== -->
<li>
<section class="constructor-details" id="constructor-detail">
<h2>Constructor Details</h2>
<ul class="member-list">
<li>
<section class="detail" id="&lt;init&gt;()">
<h3>PorterStemmer</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="element-name">PorterStemmer</span>()</div>
</section>
</li>
</ul>
</section>
</li>
<!-- ============ METHOD DETAIL ========== -->
<li>
<section class="method-details" id="method-detail">
<h2>Method Details</h2>
<ul class="member-list">
<li>
<section class="detail" id="reset()">
<h3>reset</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">void</span>&nbsp;<span class="element-name">reset</span>()</div>
<div class="block">reset() resets the stemmer so it can stem another word. If you invoke
the stemmer by calling add(char) and then stem(), you must call reset()
before starting another word.</div>
</section>
</li>
<li>
<section class="detail" id="add(char)">
<h3>add</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">void</span>&nbsp;<span class="element-name">add</span><wbr><span class="parameters">(char&nbsp;ch)</span></div>
<div class="block">Add a character to the word being stemmed. When you are finished
adding characters, you can call stem(void) to process the word.</div>
</section>
</li>
<li>
<section class="detail" id="toString()">
<h3>toString</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></span>&nbsp;<span class="element-name">toString</span>()</div>
<div class="block">After a word has been stemmed, it can be retrieved by toString(),
or a reference to the internal buffer can be retrieved by getResultBuffer
and getResultLength (which is generally more efficient.)</div>
<dl class="notes">
<dt>Overrides:</dt>
<dd><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html#toString()" title="class or interface in java.lang" class="external-link">toString</a></code>&nbsp;in class&nbsp;<code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">Object</a></code></dd>
</dl>
</section>
</li>
<li>
<section class="detail" id="getResultLength()">
<h3>getResultLength</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">int</span>&nbsp;<span class="element-name">getResultLength</span>()</div>
<div class="block">Returns the length of the word resulting from the stemming process.</div>
</section>
</li>
<li>
<section class="detail" id="getResultBuffer()">
<h3>getResultBuffer</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">char[]</span>&nbsp;<span class="element-name">getResultBuffer</span>()</div>
<div class="block">Returns a reference to a character buffer containing the results of
the stemming process. You also need to consult getResultLength()
to determine the length of the result.</div>
</section>
</li>
<li>
<section class="detail" id="stem(java.lang.String)">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;s)</span></div>
<div class="block">Stem a word provided as a String. Returns the result as a String.</div>
</section>
</li>
<li>
<section class="detail" id="stem(java.lang.CharSequence)">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/CharSequence.html" title="class or interface in java.lang" class="external-link">CharSequence</a></span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/CharSequence.html" title="class or interface in java.lang" class="external-link">CharSequence</a>&nbsp;word)</span></div>
<div class="block">Stem a word provided as a CharSequence.
Returns the result as a CharSequence.</div>
<dl class="notes">
<dt>Specified by:</dt>
<dd><code><a href="Stemmer.html#stem(java.lang.CharSequence)">stem</a></code>&nbsp;in interface&nbsp;<code><a href="Stemmer.html" title="interface in opennlp.tools.stemmer">Stemmer</a></code></dd>
</dl>
</section>
</li>
<li>
<section class="detail" id="stem(char[])">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(char[]&nbsp;word)</span></div>
<div class="block">Stem a word contained in a char[]. Returns true if the stemming process
resulted in a word different from the input. You can retrieve the
result with getResultLength()/getResultBuffer() or toString().</div>
</section>
</li>
<li>
<section class="detail" id="stem(char[],int,int)">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(char[]&nbsp;wordBuffer,
int&nbsp;offset,
int&nbsp;wordLen)</span></div>
<div class="block">Stem a word contained in a portion of a char[] array. Returns
true if the stemming process resulted in a word different from
the input. You can retrieve the result with
getResultLength()/getResultBuffer() or toString().</div>
</section>
</li>
<li>
<section class="detail" id="stem(char[],int)">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(char[]&nbsp;word,
int&nbsp;wordLen)</span></div>
<div class="block">Stem a word contained in a leading portion of a char[] array.
Returns true if the stemming process resulted in a word different
from the input. You can retrieve the result with
getResultLength()/getResultBuffer() or toString().</div>
</section>
</li>
<li>
<section class="detail" id="stem()">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">stem</span>()</div>
<div class="block">Stem the word placed into the Stemmer buffer through calls to add().
Returns true if the stemming process resulted in a word different
from the input. You can retrieve the result with
getResultLength()/getResultBuffer() or toString().</div>
</section>
</li>
<li>
<section class="detail" id="stem(int)">
<h3>stem</h3>
<div class="member-signature"><span class="modifiers">public</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">stem</span><wbr><span class="parameters">(int&nbsp;i0)</span></div>
</section>
</li>
</ul>
</section>
</li>
</ul>
</section>
<!-- ========= END OF CLASS DATA ========= -->
</main>
<footer role="contentinfo">
<hr>
<p class="legal-copy"><small>Copyright &#169; 2025 <a href="https://www.apache.org/">The Apache Software Foundation</a>. All rights reserved.</small></p>
</footer>
</div>
</div>
</body>
</html>