static void ctxTestIO(S input, S regexp) {
  ctxTestIO("", input, regexp);
}

static void ctxTestIO(S prelude, S input, S regexp) {
  S desc = prelude + input + " -> " + regexp;
  regexp = ctxREToJavaRE(regexp);
  print("Testing: " + desc);
  try {
    ctxClearOutput();
    ctxProcessInput(input);
    ctxProcessRules();
    S output = ctxGetOutput();
    bool ok = regexpIC(regexp, output).find();
    desc += " | " + struct(output);
    addTestResult/*Verbose*/(desc, ok);
  } catch e {
    addTestResult(desc, e);
  }
}