libjava/classpath/gnu/java/util/regex/RETokenStart.java

   1 /*  gnu/regexp/RETokenStart.java
   2     Copyright (C) 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.java.util.regex;
  39
  40 import gnu.java.lang.CPStringBuilder;
  41
  42 class RETokenStart extends REToken
  43 {
  44   private String newline;       // matches after a newline
  45   private boolean check_java_line_terminators;
  46
  47   RETokenStart (int subIndex, String newline)
  48   {
  49     super (subIndex);
  50     this.newline = newline;
  51     this.check_java_line_terminators = false;
  52   }
  53
  54   RETokenStart (int subIndex, String newline, boolean b)
  55   {
  56     super (subIndex);
  57     this.newline = newline;
  58     this.check_java_line_terminators = b;
  59   }
  60
  61   @Override
  62     int getMaximumLength ()
  63   {
  64     return 0;
  65   }
  66
  67   @Override
  68     REMatch matchThis (CharIndexed input, REMatch mymatch)
  69   {
  70     // charAt(index-n) may be unknown on a Reader/InputStream. FIXME
  71     // Match after a newline if in multiline mode
  72
  73     if (check_java_line_terminators)
  74       {
  75         char ch = input.charAt (mymatch.index - 1);
  76         if (ch != CharIndexed.OUT_OF_BOUNDS)
  77           {
  78             if (ch == '\n')
  79               return mymatch;
  80             if (ch == '\r')
  81               {
  82                 char ch1 = input.charAt (mymatch.index);
  83                 if (ch1 != '\n')
  84                   return mymatch;
  85                 return null;
  86               }
  87             if (ch == '\u0085')
  88               return mymatch;   // A next-line character
  89             if (ch == '\u2028')
  90               return mymatch;   // A line-separator character
  91             if (ch == '\u2029')
  92               return mymatch;   // A paragraph-separator character
  93           }
  94       }
  95
  96     if (newline != null)
  97       {
  98         int len = newline.length ();
  99         if (mymatch.offset >= len)
 100           {
 101             boolean found = true;
 102             char z;
 103             int i = 0;          // position in REToken.newline
 104             char ch = input.charAt (mymatch.index - len);
 105             do
 106               {
 107                 z = newline.charAt (i);
 108                 if (ch != z)
 109                   {
 110                     found = false;
 111                     break;
 112                   }
 113                 ++i;
 114                 ch = input.charAt (mymatch.index - len + i);
 115               }
 116             while (i < len);
 117
 118             if (found)
 119               return mymatch;
 120           }
 121       }
 122
 123     // Don't match at all if REG_NOTBOL is set.
 124     if ((mymatch.eflags & RE.REG_NOTBOL) > 0)
 125       return null;
 126
 127     if ((mymatch.eflags & RE.REG_ANCHORINDEX) > 0)
 128       return (mymatch.anchor == mymatch.offset) ? mymatch : null;
 129     else
 130       return ((mymatch.index == 0) && (mymatch.offset == 0)) ? mymatch : null;
 131   }
 132
 133   @Override
 134     boolean returnsFixedLengthMatches ()
 135   {
 136     return true;
 137   }
 138
 139   @Override
 140     int findFixedLengthMatches (CharIndexed input, REMatch mymatch, int max)
 141   {
 142     if (matchThis (input, mymatch) != null)
 143       return max;
 144     else
 145       return 0;
 146   }
 147
 148   @Override
 149     void dump (CPStringBuilder os)
 150   {
 151     os.append ('^');
 152   }
 153 }