/// <summary>
/// Adds a dynamic test which checks if the version has changed. The test is only necessary for
/// performance as the methods will do the correct thing if called with an incorrect version.
/// </summary>
private Expression AddDynamicTestAndDefer(MetaObjectBinder binder, MetaObject[] args, ExpandoClass klass, ExpandoClass originalClass, Expression ifTestSucceeds)
{
if (originalClass != null)
{
// we are accessing a member which has not yet been defined on this class.
// We force a class promotion after the type check. If the class changes the
// promotion will fail and the set/delete will do a full lookup using the new
// class to discover the name.
Debug.Assert(originalClass != klass);
ifTestSucceeds = Expression.Block(
Expression.Call(
null,
typeof(RuntimeOps).GetMethod("ExpandoPromoteClass"),
GetLimitedSelf(),
Expression.Constant(originalClass),
Expression.Constant(klass)
),
ifTestSucceeds
);
}
return(Expression.Condition(
Expression.Call(
null,
typeof(RuntimeOps).GetMethod("ExpandoCheckVersion"),
GetLimitedSelf(),
Expression.Constant(originalClass ?? klass)
),
ifTestSucceeds,
binder.Defer(args).Expression
));
}
internal MetaObject/*!*/ CreateMetaObject(MetaObjectBinder/*!*/ action, MetaObject/*!*/[]/*!*/ siteArgs) {
var expr = _error ? Ast.Throw(_result) : _result;
Restrictions restrictions;
if (_condition != null) {
var deferral = action.Defer(siteArgs);
expr = Ast.Condition(_condition, AstUtils.Convert(expr, typeof(object)), deferral.Expression);
restrictions = deferral.Restrictions;
} else {
restrictions = Restrictions.Empty;
}
if (_temps != null) {
expr = Ast.Block(_temps, expr);
}
if (_restriction != null) {
restrictions = restrictions.Merge(Restrictions.GetExpressionRestriction(_restriction));
}
return new MetaObject(expr, restrictions);
}
/// <summary>
/// Adds a dynamic test which checks if the version has changed. The test is only necessary for
/// performance as the methods will do the correct thing if called with an incorrect version.
/// </summary>
private Expression AddDynamicTestAndDefer(MetaObjectBinder binder, MetaObject[] args, ExpandoClass klass, ExpandoClass originalClass, Expression ifTestSucceeds) {
if (originalClass != null) {
// we are accessing a member which has not yet been defined on this class.
// We force a class promotion after the type check. If the class changes the
// promotion will fail and the set/delete will do a full lookup using the new
// class to discover the name.
Debug.Assert(originalClass != klass);
ifTestSucceeds = Expression.Block(
Expression.Call(
null,
typeof(RuntimeOps).GetMethod("ExpandoPromoteClass"),
GetLimitedSelf(),
Expression.Constant(originalClass),
Expression.Constant(klass)
),
ifTestSucceeds
);
}
return Expression.Condition(
Expression.Call(
null,
typeof(RuntimeOps).GetMethod("ExpandoCheckVersion"),
GetLimitedSelf(),
Expression.Constant(originalClass ?? klass)
),
ifTestSucceeds,
binder.Defer(args).Expression
);
}
