mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionTokenizer.cs

   1 //
   2 // ConditionTokenizer.cs
   3 //
   4 // Author:
   5 //   Marek Sieradzki (marek.sieradzki@gmail.com)
   6 //   Jaroslaw Kowalski <jaak@jkowalski.net>
   7 //
   8 // (C) 2006 Marek Sieradzki
   9 // (C) 2004-2006 Jaroslaw Kowalski
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29
  30 #if NET_2_0
  31
  32 using System;
  33 using System.Collections;
  34 using System.Collections.Generic;
  35 using System.Collections.Specialized;
  36 using System.Text;
  37
  38 namespace Microsoft.Build.BuildEngine {
  39
  40         internal sealed class ConditionTokenizer {
  41
  42                 string  inputString = null;
  43                 int     position = 0;
  44                 int     tokenPosition = 0;
  45
  46                 Token   token;
  47
  48 //              bool    ignoreWhiteSpace = true;
  49
  50                 static TokenType[] charIndexToTokenType = new TokenType[128];
  51                 static Dictionary <string, TokenType> keywords = new Dictionary <string, TokenType> (StringComparer.InvariantCultureIgnoreCase);
  52
  53                 static ConditionTokenizer ()
  54                 {
  55                         for (int i = 0; i < 128; i++)
  56                                 charIndexToTokenType [i] = TokenType.Invalid;
  57
  58                         foreach (CharToTokenType cht in charToTokenType)
  59                                 charIndexToTokenType [(int) cht.ch] = cht.tokenType;
  60
  61                         keywords.Add ("and", TokenType.And);
  62                         keywords.Add ("or", TokenType.Or);
  63                 }
  64
  65                 public ConditionTokenizer ()
  66                 {
  67 //                      this.ignoreWhiteSpace = true;
  68                 }
  69
  70                 public void Tokenize (string s)
  71                 {
  72                         if (s == null)
  73                                 throw new ArgumentNullException ("s");
  74
  75                         this.inputString = s;
  76                         this.position = 0;
  77                         this.token = new Token (null, TokenType.BOF);
  78
  79                         GetNextToken ();
  80                 }
  81
  82                 void SkipWhiteSpace ()
  83                 {
  84                         int ch;
  85
  86                         while ((ch = PeekChar ()) != -1) {
  87                                 if (!Char.IsWhiteSpace ((char)ch))
  88                                         break;
  89                                 ReadChar ();
  90                         }
  91                 }
  92
  93                 int PeekChar ()
  94                 {
  95                         if (position < inputString.Length)
  96                                 return (int) inputString [position];
  97                         else
  98                                 return -1;
  99                 }
 100
 101                 int ReadChar ()
 102                 {
 103                         if (position < inputString.Length)
 104                                 return (int) inputString [position++];
 105                         else
 106                                 return -1;
 107                 }
 108
 109                 public void Expect (TokenType type)
 110                 {
 111                         if (token.Type != type)
 112                                 throw new ExpressionParseException ("Expected token type of type: " + type + ", got " + token.Type +
 113                                         " (" + token.Value + ") .");
 114
 115                         GetNextToken ();
 116                 }
 117
 118                 public bool IsEOF ()
 119                 {
 120                         return token.Type == TokenType.EOF;
 121                 }
 122
 123                 public bool IsNumber ()
 124                 {
 125                         return token.Type == TokenType.Number;
 126                 }
 127
 128                 public bool IsToken (TokenType type)
 129                 {
 130                         return token.Type == type;
 131                 }
 132
 133                 public bool IsPunctation ()
 134                 {
 135                         return (token.Type >= TokenType.FirstPunct && token.Type < TokenType.LastPunct);
 136                 }
 137
 138                 // FIXME: add 'and' and 'or' tokens
 139                 public void GetNextToken ()
 140                 {
 141                         if (token.Type == TokenType.EOF)
 142                                 throw new ExpressionParseException ("Cannot read past the end of stream.");
 143
 144                         SkipWhiteSpace ();
 145
 146                         tokenPosition = position;
 147
 148 //                      int i = PeekChar ();
 149                         int i = ReadChar ();
 150
 151                         if (i == -1) {
 152                                 token = new Token (null, TokenType.EOF);
 153                                 return;
 154                         }
 155
 156                         char ch = (char) i;
 157
 158
 159                         // FIXME: looks like a hack: if '-' is here '->' won't be tokenized
 160                         // maybe we should treat item reference as a token
 161                         if (Char.IsDigit (ch) || ch == '-') {
 162                                 StringBuilder sb = new StringBuilder ();
 163
 164                                 sb.Append (ch);
 165
 166                                 while ((i = PeekChar ()) != -1) {
 167                                         ch = (char) i;
 168
 169                                         if (Char.IsDigit (ch) || ch == '.')
 170                                                 sb.Append ((char) ReadChar ());
 171                                         else
 172                                                 break;
 173                                 }
 174
 175                                 token = new Token (sb.ToString (), TokenType.Number);
 176                         } else if (ch == '\'') {
 177                                 StringBuilder sb = new StringBuilder ();
 178                                 string temp;
 179
 180                                 sb.Append (ch);
 181
 182                                 while ((i = PeekChar ()) != -1) {
 183                                         ch = (char) i;
 184
 185                                         sb.Append ((char) ReadChar ());
 186
 187                                         if (ch == '\'')
 188                                                 break;
 189                                 }
 190
 191                                 temp = sb.ToString ();
 192
 193                                 token = new Token (temp.Substring (1, temp.Length - 2), TokenType.String);
 194
 195                         } else  if (ch == '_' || Char.IsLetter (ch)) {
 196                                 StringBuilder sb = new StringBuilder ();
 197
 198                                 sb.Append ((char) ch);
 199
 200                                 while ((i = PeekChar ()) != -1) {
 201                                         if ((char) i == '_' || Char.IsLetterOrDigit ((char) i))
 202                                                 sb.Append ((char) ReadChar ());
 203                                         else
 204                                                 break;
 205                                 }
 206
 207                                 string temp = sb.ToString ();
 208
 209                                 if (keywords.ContainsKey (temp))
 210                                         token = new Token (temp, keywords [temp]);
 211                                 else
 212                                         token = new Token (temp, TokenType.String);
 213
 214                         } else if (ch == '!' && PeekChar () == (int) '=') {
 215                                 token = new Token ("!=", TokenType.NotEqual);
 216                                 ReadChar ();
 217                         } else if (ch == '<' && PeekChar () == (int) '=') {
 218                                 token = new Token ("<=", TokenType.LessOrEqual);
 219                                 ReadChar ();
 220                         } else if (ch == '>' && PeekChar () == (int) '=') {
 221                                 token = new Token (">=", TokenType.GreaterOrEqual);
 222                                 ReadChar ();
 223                         } else if (ch == '=' && PeekChar () == (int) '=') {
 224                                 token = new Token ("==", TokenType.Equal);
 225                                 ReadChar ();
 226                         } else if (ch >= 32 && ch < 128) {
 227                                 if (charIndexToTokenType [ch] != TokenType.Invalid) {
 228                                         token = new Token (new String (ch, 1), charIndexToTokenType [ch]);
 229                                         return;
 230                                 } else
 231                                         throw new ExpressionParseException (String.Format ("Invalid punctuation: {0}", ch));
 232                         } else
 233                                 throw new ExpressionParseException (String.Format ("Invalid token: {0}", ch));
 234                 }
 235
 236                 public int TokenPosition {
 237                         get { return tokenPosition; }
 238                 }
 239
 240                 public Token Token {
 241                         get { return token; }
 242                 }
 243
 244 /*
 245                 public bool IgnoreWhiteSpace {
 246                         get { return ignoreWhiteSpace; }
 247                         set { ignoreWhiteSpace = value; }
 248                 }
 249 */
 250
 251                 struct CharToTokenType {
 252                         public char ch;
 253                         public TokenType tokenType;
 254
 255                         public CharToTokenType (char ch, TokenType tokenType)
 256                         {
 257                                 this.ch = ch;
 258                                 this.tokenType = tokenType;
 259                         }
 260                 }
 261
 262                 static CharToTokenType[] charToTokenType = {
 263                         new CharToTokenType ('<', TokenType.Less),
 264                         new CharToTokenType ('>', TokenType.Greater),
 265                         new CharToTokenType ('=', TokenType.Equal),
 266                         new CharToTokenType ('(', TokenType.LeftParen),
 267                         new CharToTokenType (')', TokenType.RightParen),
 268                         new CharToTokenType ('.', TokenType.Dot),
 269                         new CharToTokenType (',', TokenType.Comma),
 270                         new CharToTokenType ('!', TokenType.Not),
 271                         new CharToTokenType ('@', TokenType.Item),
 272                         new CharToTokenType ('$', TokenType.Property),
 273                         new CharToTokenType ('%', TokenType.Metadata),
 274                         new CharToTokenType ('\'', TokenType.Apostrophe),
 275                 };
 276         }
 277 }
 278
 279 #endif