code: /*
  * Copyright 2014 Basis Technology Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
  
  package com.basistech.tclre;
  
  import org.junit.Test;
  
  import static com.basistech.tclre.Utils.Matches.matches;
  import static org.hamcrest.CoreMatchers.not;
  import static org.hamcrest.MatcherAssert.assertThat;
  
  /**
   * Let's imagine that both of the characters A and a fall at the same place in the collating sequence;
   * they belong to the same equivalence class. In that case, both of the bracket expressions
   * [[=A=]b] and [[=a=]b] are equivalent to writing [Aab]. As another example, if o and ô are
   * members of an equivalence class, then all of the bracket expressions [[=o=]], [[=ô=]], and
   * [oô] match those same two characters.
   */
  public class EquivalenceClassTest extends Utils {
  
      @Test
      public void testSimpleEqv() throws Exception {
          RePattern exp = HsrePattern.compile("[[=a=]]", PatternFlags.ADVANCED, PatternFlags.EXPANDED);
          assertThat("a", matches(exp));
          // C didn't implement this, and neither do we.
          assertThat("A", not(matches(exp)));
      }
  }
  