Re: [Libclc-developers] Introducing the double linked list interface

[Michael B.A. <mb...@io...>]

On Mon, 17 Mar 2003 19:37:01 -0500
Bryan Donlan <bd...@bd...> wrote:

> > typedef struct CLC_DL_NODE
> 
> I don't think struct of typedef names should be uppercase. IMO, only enums and 
> #defines should be uppercase.

I second that. It appears we need a style document or a consistent
codebase to model the code after.

> > CLC_DL_NODE *clc_dl_FindFirst(CLC_DL_LIST *list,
> >                               int type,
> >                               size_t size,
> >                               void *find,
> >                               int (*cmp)(int typekey,
> >                                          const void *datakey,
> >                                          int typenode,
> >                                          const void *datanode),
> >                               int dir,
> >                               CLC_DL_SEARCH_DATA *srch);

This is far too complicated. Also these callback interfaces are less
pleasant than a simple iterator interface because you frequently operate
on variable on the stack.

I would just have an iterate function that initializes the search context
object and a next object that returns each element. I don't see the
advantage of returning the first element with the initial call. It's
a little awkward programatically actually.

Incedentally the Linux kernel uses a clever list implementation. The
clever part probably wouldn't go over too well here but the basic idea
of a circular doublely linked list could be extended to provide the
traditional interface. The best description of that list ADT that I have
seen is in the Linux Device Drivers book which can be read online here:

  http://www.xml.com/ldd/chapter/book/ch10.html#t5

The list_head could be adapted to include a void *data pointer I
suppose. That might make a nice doublely linked list.

Mike

-- 
A  program should be written to model the concepts of the task it
performs rather than the physical world or a process because this
maximizes  the  potential  for it to be applied to tasks that are
conceptually  similar and, more important, to tasks that have not
yet been conceived.