title: ANTLR4: Comma not detected as unicode char
body: <p>I have a language where i want to parse unicode characters. Those characters are presided by %.
  So this text: <code>%,</code>, this: <code>a=&amp;,</code> or even this: <code>(a,b)=%,</code> should detect the ',' as unicode character.</p>
  
  <p>It does so until i add the pattern for (a,b).</p>
  
  <p>Here the code that works without (a,b):</p>
  
  <pre><code>grammar example;
  
  test: expr | decl;
  
  decl: (VARIABLE_DECLARATION? ID ) '=' expr
      ;
  
  VARIABLE_DECLARATION
      : 'public' | 'private'
      ;
  
  
  expr: unicode;
  
  unicode: '%' CHAR;
  ID:  ('a'..'z'|'A'..'Z'|'!') ('a'..'z'|'A'..'Z'|'0'..'9'|'_'|'!'|'?')*;
  CHAR:     // Other_Punctuation
          '\u{0021}'..'\u{0023}'   // [!..#] Basic Latin
       |  '\u{0025}'..'\u{0027}'   // [%..'] Basic Latin
       |  '\u{002a}'             // [*] Basic Latin
       |  '\u{002c}'             // [,] Basic Latin
       |  '\u{002e}'..'\u{002f}'   // [.../] Basic Latin
       |  '\u{003a}'..'\u{003b}'   // [:..;] Basic Latin
       |  '\u{003f}'..'\u{0040}'   // [?..@] Basic Latin
       |  '\u{005c}'             // [\] Basic Latin
  ;
  </code></pre>
  
  <p>with this i get the following error: mismatched input ',' expecting CHAR</p>
  
  <pre><code>    grammar example;
  
      test: expr | decl;
  
      decl: (VARIABLE_DECLARATION? ID | '('ID (',' ID)* ')' ) '=' expr
      ;
  
      VARIABLE_DECLARATION
      : 'public' | 'private'
      ;
  
  
      expr: unicode;
  
  unicode: '%' CHAR;
  ID:  ('a'..'z'|'A'..'Z'|'!') ('a'..'z'|'A'..'Z'|'0'..'9'|'_'|'!'|'?')*;
  CHAR:     // Other_Punctuation
          '\u{0021}'..'\u{0023}'   // [!..#] Basic Latin
       |  '\u{0025}'..'\u{0027}'   // [%..'] Basic Latin
       |  '\u{002a}'             // [*] Basic Latin
       |  '\u{002c}'             // [,] Basic Latin
       |  '\u{002e}'..'\u{002f}'   // [.../] Basic Latin
       |  '\u{003a}'..'\u{003b}'   // [:..;] Basic Latin
       |  '\u{003f}'..'\u{0040}'   // [?..@] Basic Latin
       |  '\u{005c}'             // [\] Basic Latin
  ;
  </code></pre>
  
  <p>how can i solve that?</p>