protected virtual ColumnAssignment VisitColumnAssignment(ColumnAssignment ca)
{
ColumnExpression c = (ColumnExpression)this.Visit(ca.Column);
Expression e = this.Visit(ca.Expression);
return(this.UpdateColumnAssignment(ca, c, e));
}
protected ColumnAssignment UpdateColumnAssignment(ColumnAssignment ca, ColumnExpression c, Expression e)
{
if (c != ca.Column || e != ca.Expression)
{
return(new ColumnAssignment(c, e));
}
return(ca);
}
protected virtual ReadOnlyCollection <ColumnAssignment> VisitColumnAssignments(ReadOnlyCollection <ColumnAssignment> assignments)
{
List <ColumnAssignment> alternate = null;
for (int i = 0, n = assignments.Count; i < n; i++)
{
ColumnAssignment assignment = this.VisitColumnAssignment(assignments[i]);
if (alternate == null && assignment != assignments[i])
{
alternate = assignments.Take(i).ToList();
}
if (alternate != null)
{
alternate.Add(assignment);
}
}
if (alternate != null)
{
return(alternate.AsReadOnly());
}
return(assignments);
}
