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

   1 //\r
   2 // assembly:    System\r
   3 // namespace:   System.Text.RegularExpressions\r
   4 // file:        match.cs\r
   5 //\r
   6 // author:      Dan Lewis (dlewis@gmx.co.uk)\r
   7 //              (c) 2002\r
   8 \r
   9 using System;\r
  10 \r
  11 namespace System.Text.RegularExpressions {\r
  12 \r
  13         [Serializable]\r
  14         public class Capture {\r
  15                 public int Index {\r
  16                         get {\r
  17                                 if (!IsDefined)\r
  18                                         return 0;               // capture not completed\r
  19                                 else if (start <= end)\r
  20                                         return start;           // normal capture\r
  21                                 else\r
  22                                         return end;             // reverse capture\r
  23                         }\r
  24                 }\r
  25 \r
  26                 public int Length {\r
  27                         get {\r
  28                                 if (!IsDefined)\r
  29                                         return 0;\r
  30                                 else if (start <= end)\r
  31                                         return end - start;\r
  32                                 else\r
  33                                         return start - end;\r
  34                         }\r
  35                 }\r
  36 \r
  37                 public string Value {\r
  38                         get { return IsDefined ? text.Substring (Index, Length) : ""; }\r
  39                 }\r
  40 \r
  41                 public override string ToString () {\r
  42                         return Value;\r
  43                 }\r
  44 \r
  45                 // internal members\r
  46 \r
  47                 internal Capture () {                   // empty capture\r
  48                         this.previous = null;\r
  49                         this.text = null;\r
  50                         this.checkpoint = 0;\r
  51 \r
  52                         this.start = -1;\r
  53                         this.end = -1;\r
  54                 }\r
  55 \r
  56                 internal Capture (Capture cap) {        // copy constructor\r
  57                         this.previous = cap.previous;\r
  58                         this.text = cap.text;\r
  59                         this.checkpoint = cap.checkpoint;\r
  60 \r
  61                         this.start = cap.start;\r
  62                         this.end = cap.end;\r
  63                 }\r
  64 \r
  65                 internal Capture (string text) {        // first capture\r
  66                         this.previous = null;\r
  67                         this.text = text;\r
  68                         this.checkpoint = 0;\r
  69 \r
  70                         this.start = -1;\r
  71                         this.end = -1;\r
  72                 }\r
  73                 \r
  74                 internal Capture (Capture previous, int checkpoint) {\r
  75                         this.previous = previous;\r
  76                         this.text = previous.text;\r
  77                         this.checkpoint = checkpoint;\r
  78 \r
  79                         this.start = -1;\r
  80                         this.end = -1;\r
  81                 }\r
  82 \r
  83                 internal Capture Previous {\r
  84                         get { return previous; }\r
  85                 }\r
  86 \r
  87                 internal string Text {\r
  88                         get { return text; }\r
  89                 }\r
  90 \r
  91                 internal int Checkpoint {\r
  92                         get { return checkpoint; }\r
  93                 }\r
  94 \r
  95                 internal bool IsDefined {\r
  96                         get { return start >= 0 && end >= 0; }\r
  97                 }\r
  98 \r
  99                 internal Capture GetLastDefined () {\r
 100                         Capture cap = this;\r
 101                         while (cap != null && !cap.IsDefined)\r
 102                                 cap = cap.Previous;\r
 103 \r
 104                         return cap;\r
 105                 }\r
 106 \r
 107                 internal void Open (int ptr) {\r
 108                         this.start = ptr;\r
 109                 }\r
 110 \r
 111                 internal void Close (int ptr) {\r
 112                         this.end = ptr;\r
 113                 }\r
 114 \r
 115                 // private\r
 116 \r
 117                 private int start, end;\r
 118                 private string text;\r
 119                 private int checkpoint;\r
 120                 private Capture previous;\r
 121         }\r
 122 \r
 123         public class Group : Capture {\r
 124                 public static Group Synchronized (Group inner) {\r
 125                         return inner;   // is this enough?\r
 126                 }\r
 127 \r
 128                 public CaptureCollection Captures {\r
 129                         get { return captures; }\r
 130                 }\r
 131 \r
 132                 public bool Success {\r
 133                         get { return GetLastDefined () != null; }\r
 134                 }\r
 135 \r
 136                 // internal\r
 137 \r
 138                 internal Group () : base () {\r
 139                 }\r
 140                 \r
 141                 internal Group (Capture last) : base (last) {\r
 142                         captures = new CaptureCollection (last);\r
 143 \r
 144                         // TODO make construction of captures lazy\r
 145                 }\r
 146 \r
 147                 private CaptureCollection captures;\r
 148         }\r
 149 \r
 150         public class Match : Group {\r
 151                 public static Match Empty {\r
 152                         get { return empty; }\r
 153                 }\r
 154                 \r
 155                 public static Match Synchronized (Match inner) {\r
 156                         return inner;   // FIXME need to sync on machine access\r
 157                 }\r
 158                 \r
 159                 public GroupCollection Groups {\r
 160                         get { return groups; }\r
 161                 }\r
 162 \r
 163                 public Match NextMatch () {\r
 164                         if (this == Empty)\r
 165                                 return Empty;\r
 166 \r
 167                         int scan_ptr = regex.RightToLeft ? Index : Index + Length;\r
 168 \r
 169                         // next match after an empty match: make sure scan ptr makes progress\r
 170                         \r
 171                         if (Length == 0)\r
 172                                 scan_ptr += regex.RightToLeft ? -1 : +1;\r
 173 \r
 174                         return machine.Scan (regex, Text, scan_ptr, text_length);\r
 175                 }\r
 176 \r
 177                 public virtual string Result (string replacement) {\r
 178                         return ReplacementEvaluator.Evaluate (replacement, this);\r
 179                 }\r
 180 \r
 181                 // internal\r
 182 \r
 183                 internal Match () : base () {\r
 184                         this.regex = null;\r
 185                         this.machine = null;\r
 186                         this.text_length = 0;\r
 187                         this.groups = new GroupCollection ();\r
 188 \r
 189                         groups.Add (this);\r
 190                 }\r
 191                 \r
 192                 internal Match (Regex regex, IMachine machine, int text_length, Capture[] captures) : base (captures[0]) {\r
 193                         this.regex = regex;\r
 194                         this.machine = machine;\r
 195                         this.text_length = text_length;\r
 196                         this.groups = new GroupCollection ();\r
 197 \r
 198                         groups.Add (this);\r
 199                         for (int i = 1; i < captures.Length; ++ i)\r
 200                                 groups.Add (new Group (captures[i]));\r
 201                 }\r
 202 \r
 203                 internal Regex Regex {\r
 204                         get { return regex; }\r
 205                 }\r
 206 \r
 207                 // private\r
 208 \r
 209                 private Regex regex;\r
 210                 private IMachine machine;\r
 211                 private int text_length;\r
 212                 private GroupCollection groups;\r
 213 \r
 214                 private static Match empty = new Match ();\r
 215         }\r
 216 }\r