On Wed, 14 May 2014 21:38:33 +0200 Tobias Boege <tabo...@gmail.com> wrote:
> Hi Benoit, > > when we wanted to sort a 2d array (table) by a specific column, variable at > runtime, we did the following: > > 1. Create the class, let's call it "Record", to represent the table > records which implements a _compare() method and has a SortField > property which indicates to _compare() which column we want to sort > by. > 2. Create a class "RecordGroup" which Inherits Object[] and has a > SortField(Field As Integer, Optional Mode As Integer) method which is > a multicolumn-aware version of Sort: > > Public Sub SortField(Field As Integer, Optional Mode As Integer) > Dim iInd As Integer > > For iInd = 0 To Super.Count - 1 > Super[iInd].SortField = Field > Next > Super.Sort(Mode) > End > 3. Then, we must work with RecordGroups which we can sort by, say, column 7 > using myGroup.SortField(7). > > You see that we need to set each object's SortField property to the Field > value in order to make the _compare()s work together as we desire. If some > objects "don't get it", we will lose transitivity of our relation and the > sort may fail. > > We can't use static properties in the Record class either because we may > want to have multiple groups. > > These redundant assignments are what bothers us (also that we need a custom > array type that we called "Group" to hide our clumsiness in communicating > the SortField to each object). [ There are other ways of efficiently grouping > elements but the ones I can think of are pretty obscure - but I'm open for > suggestions! If none: ] > > Is it possible to - and what will existing code say if we - change > _compare()'s signature to > > Public Sub _compare(hOther As Object, Optional vPrivate As Variant) > > and have a new corresponding optional argument to Object[].Sort() and > MyClass[].Sort()? Sorting by column 7 in the above scenario would boil > down to calling (without groups) Record[].Sort(7). > > Regards, > Tobi > I would really like to see this too! My attempts at providing a generic sorting mechanism along the lines suggested by Tobi's approach have been less than successful for exactly the same reasons. -- B Bruen <bbr...@paddys-hill.net> ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
