;</span>

    nextToken = tokenizer (result = <span class="hljs-keyword">new</span> Result), expr =  <span class="hljs-string">'a !a'</span>

    expect(nextToken()).toBe <span class="hljs-string">'a'</span>
    expect(nextToken()).toBe <span class="hljs-literal">undefined</span>

    expect(result.messages).sameStructure [
      {type: <span class="hljs-string">'error'</span>,  code: <span class="hljs-string">'dsc.invalidExpression'</span>, value: expr, position: <span class="hljs-number">2</span>}
 