visitOptional method
Implementation
@override
ExpressionGenerator visitOptional(OptionalExpression node) {
final g = ExpressionGenerator(node);
g.generate = (block) {
g.allocateVariable();
final child = node.expression;
final g1 = acceptChild(child, g);
g1.addVariables(g);
g1.variable = g.variable;
g1.generate(block);
block.assign(Members.ok, true$);
};
return g;
}