If "keys of the coll1 object" refers to variables in the objects, then the problem is simply, because that the copy of collection contains same object references as the original collection. Then to correct that you need to create new objects for the new collection.
Jussi On Tue, Sep 6, 2016 at 11:19 PM, Tobias Boege <tabo...@gmail.com> wrote: > On Tue, 06 Sep 2016, PICCORO McKAY Lenz wrote: > > i have a function that returns a collections of collections, named > > getPedidogeneral > > > > i mean, this function returns object coll1 that inside each key is a id > of > > a object that also are a collection too > > > > i try to copy the firts to other, i mean coll2 = coll1.copy() or coll2 = > > coll1 > > > > i noted that the refers inside coll1 are the same as coll2! > > > > the problem are that if i modified some keys of the coll1 object, same > key > > in the coll2 object also its modified! > > > > and so the only way to modified each collection without affecting the > other > > its obtain a copy with differents references but same contents, so i must > > recall the function for that! > > > > to ilustrate i posted a image > > > > That is the expected behaviour. Copying coll1 should create a new > Collection > with exactly the same contents, i.e. a /shallow/ copy of the Collection, as > opposed to a /deep/ copy in which all contents of coll1 would also have > been > copied recursively. > > There's something called Rice's Theorem which forbids the existence of a > general algorithm which can create a deep copy of any Gambas object [*]. > Since a Collection may hold any object, it is impossible to create deep > copies of Collections, *in general*. > > Of course, if you know that your Collection only contains Collections, > which, > in turn, you are sure only contain primitive data types (which can easily > be > deep-copied), then you can, of course, write a deep copy function: > > '' Assumes ~cCol~ is a Collection of Collections, each of which contains > '' data of primitive types. > Private Function CopyMyCollection(cCol As Collection) > Private cNew As New Collection > Dim cElt As Collection > > For Each cElt In cCol > cNew[cCol.Key] = cElt.Copy() > Next > Return cNew > End > > Regards, > Tobi > > [*] More specifically it follows from Rice that you can't decide if a > 64-bit > word is meant by the program to be a number or a pointer. /If/ a > general > copy routine for objects existed, you could apply it to any given > 64-bit > word and if the copy is different from the original, it must have been > a > pointer (which the copy routine had to deep-copy), and otherwise it > must > have been a number because its value had to be preserved by the copier. > But because that is undecidable, you get a contradcition. > > -- > "There's an old saying: Don't change anything... ever!" -- Mr. Monk > > ------------------------------------------------------------ > ------------------ > _______________________________________________ > Gambas-user mailing list > Gambas-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/gambas-user > ------------------------------------------------------------------------------ _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
