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 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant.types;

import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.regexp.Regexp;
import org.apache.tools.ant.util.regexp.RegexpFactory;

A regular expression datatype.  Keeps an instance of the
compiled expression for speed purposes.  This compiled
expression is lazily evaluated (it is compiled the first
time it is needed).  The syntax is the dependent on which
regular expression type you are using.  The system property
"ant.regexp.regexpimpl" will be the classname of the implementation
that will be used.
Available implementations:
  org.apache.tools.ant.util.regexp.Jdk14RegexpRegexp (default)
       Based on the JDK's built-in regular expression package
  org.apache.tools.ant.util.regexp.JakartaOroRegexp
       Based on the jakarta-oro package
  org.apache.tools.ant.util.regexp.JakartaRegexpRegexp
       Based on the jakarta-regexp package

  <regexp [ [id="id"] pattern="expression" | refid="id" ]
  />

See Also:
Perl5Compiler
RE
Pattern
Regexp
@ant.datatype
name="regexp"/**
 * A regular expression datatype.  Keeps an instance of the
 * compiled expression for speed purposes.  This compiled
 * expression is lazily evaluated (it is compiled the first
 * time it is needed).  The syntax is the dependent on which
 * regular expression type you are using.  The system property
 * "ant.regexp.regexpimpl" will be the classname of the implementation
 * that will be used.
 *
 * <pre>
 * Available implementations:
 *
 *   org.apache.tools.ant.util.regexp.Jdk14RegexpRegexp (default)
 *        Based on the JDK's built-in regular expression package
 *
 *   org.apache.tools.ant.util.regexp.JakartaOroRegexp
 *        Based on the jakarta-oro package
 *
 *   org.apache.tools.ant.util.regexp.JakartaRegexpRegexp
 *        Based on the jakarta-regexp package
 * </pre>
 *
 * <pre>
 *   &lt;regexp [ [id="id"] pattern="expression" | refid="id" ]
 *   /&gt;
 * </pre>
 *
 * @see org.apache.oro.text.regex.Perl5Compiler
 * @see org.apache.regexp.RE
 * @see java.util.regex.Pattern
 *
 * @see org.apache.tools.ant.util.regexp.Regexp
 *
 * @ant.datatype name="regexp"
 */
public class RegularExpression extends DataType {
    
Name of this data type /** Name of this data type */
    public static final String DATA_TYPE_NAME = "regexp";
    private boolean alreadyInit = false;

    // The regular expression factory
    private static final RegexpFactory FACTORY = new RegexpFactory();

    private Regexp regexp = null;
    // temporary variable
    private String myPattern;
    private boolean setPatternPending = false;

    private void init(Project p) {
        if (!alreadyInit) {
            this.regexp = FACTORY.newRegexp(p);
            alreadyInit = true;
        }
    }
    private void setPattern() {
        if (setPatternPending) {
            regexp.setPattern(myPattern);
            setPatternPending = false;
        }
    }
    
sets the regular expression pattern
Params:
pattern – regular expression pattern/**
     * sets the regular expression pattern
     * @param pattern regular expression pattern
     */
    public void setPattern(String pattern) {
        if (regexp == null) {
            myPattern = pattern;
            setPatternPending = true;
        } else {
            regexp.setPattern(pattern);
        }
    }

    
Gets the pattern string for this RegularExpression in the
given project.
Params:
p – project
Returns:
pattern/***
     * Gets the pattern string for this RegularExpression in the
     * given project.
     * @param p project
     * @return pattern
     */
    public String getPattern(Project p) {
        init(p);
        if (isReference()) {
            return getRef(p).getPattern(p);
        }
        setPattern();
        return regexp.getPattern();
    }

    
provides a reference to the Regexp contained in this
Params:
p –  project
Returns:
  Regexp instance associated with this RegularExpression instance/**
     * provides a reference to the Regexp contained in this
     * @param p  project
     * @return   Regexp instance associated with this RegularExpression instance
     */
    public Regexp getRegexp(Project p) {
        init(p);
        if (isReference()) {
            return getRef(p).getRegexp(p);
        }
        setPattern();
        return this.regexp;
    }

    
Get the RegularExpression this reference refers to in
the given project.  Check for circular references too
Params:
p – project
Returns:
resolved RegularExpression instance/***
     * Get the RegularExpression this reference refers to in
     * the given project.  Check for circular references too
     * @param p project
     * @return resolved RegularExpression instance
     */
    public RegularExpression getRef(Project p) {
        return getCheckedRef(RegularExpression.class, getDataTypeName(), p);
    }
}