/// <summary>
/// This method returns 'true' when the expression doesn't reference any parameters
/// from outside the scope of the expression.
/// </summary>
static public bool IsIndependent(Expression expression)
{
var v = new DependenceChecker();
v.Visit(expression);
return(v.isIndependent);
}
internal override Expression Visit(Expression expression)
{
if (expression == null)
{
return(null);
}
bool saveIsRemote = this.isRemote;
switch (expression.NodeType)
{
case (ExpressionType)InternalExpressionType.Known:
return(expression);
case (ExpressionType)ExpressionType.Constant:
break;
default:
this.isRemote = false;
base.Visit(expression);
if (!this.isRemote &&
expression.NodeType != ExpressionType.Lambda &&
expression.NodeType != ExpressionType.Quote &&
DependenceChecker.IsIndependent(expression))
{
this.locals[expression] = true; // Not 'Add' because the same expression may exist in the tree twice.
}
break;
}
if (typeof(ITable).IsAssignableFrom(expression.Type) ||
typeof(DataContext).IsAssignableFrom(expression.Type))
{
this.isRemote = true;
}
this.isRemote |= saveIsRemote;
return(expression);
}
/// <summary>
/// This method returns 'true' when the expression doesn't reference any parameters
/// from outside the scope of the expression.
/// </summary>
static public bool IsIndependent(Expression expression) {
var v = new DependenceChecker();
v.Visit(expression);
return v.isIndependent;
}