mcs/ilasm/scanner/ILReader.cs

   1 // ILReader.cs\r
   2 // Author: Sergey Chaban (serge@wildwestsoftware.com)\r
   3 \r
   4 using System;\r
   5 using System.IO;\r
   6 using System.Text;\r
   7 using System.Collections;\r
   8 \r
   9 namespace Mono.ILASM {\r
  10 \r
  11 \r
  12         /// <summary>\r
  13         /// </summary>\r
  14         public class ILReader {\r
  15                 \r
  16                 private StreamReader reader;\r
  17                 private Stack putback_stack;\r
  18                 private Location location;\r
  19                 private Location markedLocation;\r
  20                 \r
  21                 public ILReader (StreamReader reader)\r
  22                 {\r
  23                         this.reader = reader;\r
  24                         putback_stack = new Stack ();\r
  25                         \r
  26                         location = new Location ();\r
  27                         markedLocation = Location.Unknown;\r
  28                 }\r
  29 \r
  30 \r
  31 \r
  32                 /// <summary>\r
  33                 /// </summary>\r
  34                 public Location Location {\r
  35                         get {\r
  36                                 return location;\r
  37                         }\r
  38                 }\r
  39 \r
  40 \r
  41                 /// <summary>\r
  42                 /// Provides access to underlying StreamReader.\r
  43                 /// </summary>\r
  44                 public StreamReader BaseReader {\r
  45                         get {\r
  46                                 return reader;\r
  47                         }\r
  48                 }\r
  49 \r
  50                 private int DoRead ()\r
  51                 {\r
  52                         if (putback_stack.Count > 0) \r
  53                                 return (char) putback_stack.Pop ();\r
  54                         \r
  55                         return reader.Read ();\r
  56                 }\r
  57 \r
  58                 private int DoPeek ()\r
  59                 {\r
  60                         if (putback_stack.Count > 0)\r
  61                                 return (char) putback_stack.Peek ();\r
  62                         \r
  63                         return reader.Peek ();\r
  64                 }\r
  65 \r
  66                 /// <summary>\r
  67                 /// </summary>\r
  68                 /// <returns></returns>\r
  69                 public int Read ()\r
  70                 {\r
  71                         return DoRead ();\r
  72                 }\r
  73 \r
  74                 /// <summary>\r
  75                 /// </summary>\r
  76                 /// <returns></returns>\r
  77                 public int Peek ()\r
  78                 {\r
  79                         return DoPeek ();\r
  80                 }\r
  81 \r
  82 \r
  83                 /// <summary>\r
  84                 /// </summary>\r
  85                 public void Unread (char c)\r
  86                 {\r
  87                         putback_stack.Push (c);\r
  88 \r
  89                         if ('\n' == c)\r
  90                                 location.PreviousLine ();\r
  91 \r
  92                         location.PreviousColumn ();\r
  93                 }\r
  94 \r
  95 \r
  96                 /// <summary>\r
  97                 /// </summary>\r
  98                 /// <param name="chars"></param>\r
  99                 public void Unread (char [] chars)\r
 100                 {\r
 101                         for (int i=chars.Length-1; i>=0; i--)\r
 102                                 Unread (chars[i]);                                      \r
 103                 }\r
 104 \r
 105                 /// <summary>\r
 106                 /// </summary>\r
 107                 /// <param name="c"></param>\r
 108                 public void Unread (int c)\r
 109                 {\r
 110                         Unread ((char)c);\r
 111                 }\r
 112 \r
 113 \r
 114                 /// <summary>\r
 115                 /// </summary>\r
 116                 public void SkipWhitespace ()\r
 117                 {\r
 118                         int ch = Read ();\r
 119                         for (; ch != -1 && Char.IsWhiteSpace((char) ch); ch = Read ());\r
 120                         if (ch != -1) Unread (ch);\r
 121                 }\r
 122 \r
 123 \r
 124                 /// <summary>\r
 125                 /// </summary>\r
 126                 /// <returns></returns>\r
 127                 public string ReadToWhitespace ()\r
 128                 {\r
 129                         StringBuilder sb = new StringBuilder ();\r
 130                         int ch = Read ();\r
 131                         for (; ch != -1 && !Char.IsWhiteSpace((char) ch); sb.Append ((char) ch), ch = Read ());\r
 132                         if (ch != -1) Unread (ch);\r
 133                         return sb.ToString ();\r
 134                 }\r
 135 \r
 136 \r
 137                 /// <summary>\r
 138                 /// </summary>\r
 139                 public void MarkLocation ()\r
 140                 {\r
 141                         if (markedLocation == Location.Unknown) {\r
 142                                 markedLocation = new Location (location);\r
 143                         } else {\r
 144                                 markedLocation.CopyFrom (location);\r
 145                         }\r
 146                 }\r
 147 \r
 148 \r
 149                 /// <summary>\r
 150                 /// </summary>\r
 151                 public void RestoreLocation ()\r
 152                 {\r
 153                         if (markedLocation != Location.Unknown) {\r
 154                                 location.CopyFrom (markedLocation);\r
 155                         }\r
 156                 }\r
 157 \r
 158         }\r
 159 \r
 160 }\r
 161 \r