Re: interest in extensible array module?

[Bruno Haible]

Hello Riccardo,

> I wrote an "extensible array" code as part of a larger project, and
> thought it could be of some interest to GNUlib.  However, I'm not sure
> it does not fall into the category of "stuff that would be better
> packaged separately", so I'm inquiring here first, before wrapping it
> up properly as a patch.
> 
> The "XARRAY" macro creates an array of any given C type (plus some
> optional headers), and defines functions to append/remove/insert
> elements into the array.  Documentation is in the attached C header file;
> the test case shows a usage sample.

gnulib intends to be a home for reusable and useful code like this one.
However, there is some overlap with two modules that already exist in gnulib:
  - 'xalloc' (main source files: xalloc.h, xmalloc.c),
  - 'list' and 'array-list' (main source files: gl_list.h, gl_array_list.c).

'xalloc' is lower level than your 'xarray' module; we use it when it's
not a big burden to think about memory allocations explicitly.

'list' and 'array-list' are at a higher level than your 'xarray' module:
they implement a more general "ordered list" interface. Code written with
these module can be turned into linked list, hash table, or balanced binary
tree with a change of just one line of code. On the other hand, these
modules require a 'void *' as data type; your 'xarray' is more memory
efficient when the data type is 'char' or 'double[2]'.

Does gnulib need an 'xarray' module between 'xalloc' and 'list'/'array-list'?
I'm a bit undecided. Opinions?

Bruno