public DekiScriptDom Visit(DekiScriptDomIfElse expr, DekiScriptOptimizerState state)
{
List <Tuplet <DekiScriptExpression, DekiScriptDom> > conditionals = new List <Tuplet <DekiScriptExpression, DekiScriptDom> >();
for (int i = 0; i < expr.Conditionals.Length; i++)
{
Tuplet <DekiScriptExpression, DekiScriptDom> conditional = expr.Conditionals[i];
// evaluate current branch
DekiScriptExpression inner = conditional.Item1.VisitWith(DekiScriptExpressionOptimizer.Instance, state);
DekiScriptDom node = conditional.Item2.VisitWith(this, state);
// check if test has a constant outcome
if (inner is DekiScriptLiteral)
{
if (((DekiScriptLiteral)inner).IsNilFalseZero)
{
// NOTE (steveb): this conditional will never be successful; skip it
}
else
{
// NOTE (steveb): this conditional will is always successful; make it the "else" branch
// check if there are any previous branches
if (conditionals.Count == 0)
{
// just return the inner node structure
return(node);
}
// add branch as final "else" branch
conditionals.Add(new Tuplet <DekiScriptExpression, DekiScriptDom>(null, node));
break;
}
}
else
{
conditionals.Add(new Tuplet <DekiScriptExpression, DekiScriptDom>(inner, node));
}
}
return(new DekiScriptDomIfElse(expr.Location, conditionals.ToArray()));
}
public Empty Visit(DekiScriptDomIfElse expr, DekiScriptDomEvaluationState state)
{
var context = state.Context;
var env = state.Env;
var parent = state.Parent;
try {
foreach (Tuplet <DekiScriptExpression, DekiScriptDom> conditional in expr.Conditionals)
{
// check if conditional is false
if ((conditional.Item1 != null) && conditional.Item1.VisitWith(DekiScriptExpressionEvaluation.Instance, env.NewLocalScope()).IsNilFalseZero)
{
continue;
}
// embed conditional branch
conditional.Item2.VisitWith(this, new DekiScriptDomEvaluationState(context, parent, env));
break;
}
} catch (Exception e) {
EmbedExceptionMessage(expr, env, context, e, parent);
}
return(Empty.Value);
}
