mcs/class/System/System.Text.RegularExpressions/match.cs

   1 //
   2 // assembly:    System
   3 // namespace:   System.Text.RegularExpressions
   4 // file:        match.cs
   5 //
   6 // author:      Dan Lewis (dlewis@gmx.co.uk)
   7 //              (c) 2002
   8
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31
  32 namespace System.Text.RegularExpressions {
  33
  34         [Serializable]
  35         public class Capture {
  36                 public int Index {
  37                         get { return index; }
  38                 }
  39
  40                 public int Length {
  41                         get { return length; }
  42                 }
  43
  44                 public string Value {
  45                         get {
  46                                 if (text!= null)
  47                                         return text.Substring (index, length);
  48                                 else
  49                                         return String.Empty;
  50                         }
  51                 }
  52
  53                 public override string ToString () {
  54                         return Value;
  55                 }
  56
  57                 // internal members
  58
  59                 internal Capture (string text) : this (text, 0, 0) { }
  60
  61                 internal Capture (string text, int index, int length) {
  62                         this.text = text;
  63                         this.index = index;
  64                         this.length = length;
  65                 }
  66
  67                 internal string Text {
  68                         get { return text; }
  69                 }
  70
  71                 // private
  72
  73                 internal int index, length;
  74                 internal string text;
  75         }
  76
  77         [Serializable]
  78         public class Group : Capture {
  79                 public static Group Synchronized (Group inner) {
  80                         return inner;   // is this enough?
  81                 }
  82
  83                 public CaptureCollection Captures {
  84                         get { return captures; }
  85                 }
  86
  87                 public bool Success {
  88                         get { return success; }
  89                 }
  90
  91                 // internal
  92
  93                 internal Group (string text, int[] caps) : base (text) {
  94                         this.captures = new CaptureCollection ();
  95
  96                         if (caps == null || caps.Length == 0) {
  97                                 this.success = false;
  98                                 return;
  99                         }
 100
 101                         this.success = true;
 102                         this.index = caps[0];
 103                         this.length = caps[1];
 104                         captures.Add (this);
 105                         for (int i = 2; i < caps.Length; i += 2)
 106                                 captures.Add (new Capture (text, caps[i], caps[i + 1]));
 107                         captures.Reverse ();
 108                 }
 109
 110                 internal Group (): base ("")
 111                 {
 112                         captures = new CaptureCollection ();
 113                 }
 114
 115                 private bool success;
 116                 private CaptureCollection captures;
 117         }
 118
 119         [Serializable]
 120         public class Match : Group {
 121                 public static Match Empty {
 122                         get { return empty; }
 123                 }
 124
 125                 public static Match Synchronized (Match inner) {
 126                         return inner;   // FIXME need to sync on machine access
 127                 }
 128
 129                 public virtual GroupCollection Groups {
 130                         get { return groups; }
 131                 }
 132
 133                 public Match NextMatch () {
 134                         if (this == Empty)
 135                                 return Empty;
 136
 137                         int scan_ptr = regex.RightToLeft ? Index : Index + Length;
 138
 139                         // next match after an empty match: make sure scan ptr makes progress
 140
 141                         if (Length == 0)
 142                                 scan_ptr += regex.RightToLeft ? -1 : +1;
 143
 144                         return machine.Scan (regex, Text, scan_ptr, text_length);
 145                 }
 146
 147                 public virtual string Result (string replacement) {
 148                         return ReplacementEvaluator.Evaluate (replacement, this);
 149                 }
 150
 151                 // internal
 152
 153                 internal Match () : base (null, null) {
 154                         this.regex = null;
 155                         this.machine = null;
 156                         this.text_length = 0;
 157                         this.groups = new GroupCollection ();
 158
 159                         groups.Add (this);
 160                 }
 161
 162                 internal Match (Regex regex, IMachine machine, string text, int text_length, int[][] grps) :
 163                         base (text, grps[0])
 164                 {
 165                         this.regex = regex;
 166                         this.machine = machine;
 167                         this.text_length = text_length;
 168
 169                         this.groups = new GroupCollection ();
 170                         groups.Add (this);
 171                         for (int i = 1; i < grps.Length; ++ i)
 172                                 groups.Add (new Group (text, grps[i]));
 173                 }
 174
 175                 internal Regex Regex {
 176                         get { return regex; }
 177                 }
 178
 179                 // private
 180
 181                 private Regex regex;
 182                 private IMachine machine;
 183                 private int text_length;
 184                 private GroupCollection groups;
 185
 186                 private static Match empty = new Match ();
 187         }
 188 }