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

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