::= &#39;[&#39;  expressions &#39;]&#39;

variable ::= identifier

identifier ::= [a-zA-Z] [a-zA-Z0-9_]*</code></pre>

</div>
<div id="expressions-1" class="section level3 unnumbered">
<h3>Expressions</h3>

<pre><code>
expressions ::= expression % &#39;,&#39;

expression ::= expression `?` expression `:` expression
             | expression infixOp expression
             | prefixOp expression
             | expression postfixOp
             | common_expression

constr_expression ::= constr_expression arith