protected override object DoEvaluate(CodeContext context)
{
object ret;
switch (_variable.Kind)
{
case Variable.VariableKind.Temporary:
case Variable.VariableKind.GeneratorTemporary:
if (!context.Scope.TemporaryStorage.TryGetValue(_variable, out ret))
{
throw context.LanguageContext.MissingName(_variable.Name);
}
else
{
return(ret);
}
case Variable.VariableKind.Parameter:
// This is sort of ugly: parameter variables can be stored either as locals or as temporaries (in case of $argn).
if (!context.Scope.TemporaryStorage.TryGetValue(_variable, out ret) || ret == Uninitialized.Instance)
{
return(RuntimeHelpers.LookupName(context, _variable.Name));
}
else
{
return(ret);
}
case Variable.VariableKind.Global:
return(RuntimeHelpers.LookupGlobalName(context, _variable.Name));
default:
if (!context.LanguageContext.TryLookupName(context, _variable.Name, out ret))
{
throw context.LanguageContext.MissingName(_variable.Name);
}
else if (ret == Uninitialized.Instance)
{
RuntimeHelpers.ThrowUnboundLocalError(_variable.Name);
return(null);
}
else
{
return(ret);
}
}
}