net.mograsim.plugin.core/src/net/mograsim/plugin/asm/editor/rules/AsmNumberRule.java

   1 package net.mograsim.plugin.asm.editor.rules;\r
   2 \r
   3 import org.eclipse.core.runtime.Assert;\r
   4 import org.eclipse.jface.text.rules.ICharacterScanner;\r
   5 import org.eclipse.jface.text.rules.IRule;\r
   6 import org.eclipse.jface.text.rules.IToken;\r
   7 import org.eclipse.jface.text.rules.Token;\r
   8 \r
   9 import net.mograsim.plugin.asm.AsmNumberUtil;\r
  10 \r
  11 public class AsmNumberRule implements IRule\r
  12 {\r
  13 \r
  14         /** The token to be returned when this rule is successful */\r
  15         protected IToken fToken;\r
  16 \r
  17         /**\r
  18          * Creates a rule which will return the specified token when a numerical sequence is detected.\r
  19          *\r
  20          * @param token the token to be returned\r
  21          */\r
  22         public AsmNumberRule(IToken token)\r
  23         {\r
  24                 Assert.isNotNull(token);\r
  25                 fToken = token;\r
  26         }\r
  27 \r
  28         @Override\r
  29         public IToken evaluate(ICharacterScanner scanner)\r
  30         {\r
  31                 int i = 1;\r
  32                 int c = scanner.read();\r
  33                 if (!AsmNumberUtil.isStart(c))\r
  34                         return abort(scanner, i);\r
  35                 StringBuilder sb = new StringBuilder();\r
  36                 sb.appendCodePoint(c);\r
  37                 while (true)\r
  38                 {\r
  39                         c = scanner.read();\r
  40                         i++;\r
  41                         if (AsmNumberUtil.isPart(c))\r
  42                                 sb.appendCodePoint(c);\r
  43                         else\r
  44                                 break;\r
  45                 }\r
  46                 if (!AsmNumberUtil.isNumber(sb))\r
  47                         return abort(scanner, i);\r
  48                 scanner.unread();\r
  49                 return fToken;\r
  50         }\r
  51 \r
  52         private static IToken abort(ICharacterScanner scanner, int i)\r
  53         {\r
  54                 for (int j = 0; j < i; j++)\r
  55                         scanner.unread();\r
  56                 return Token.UNDEFINED;\r
  57         }\r
  58 \r
  59 }\r