Re: linked list rewrite

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> What does the 'n' stand for in ncons?  I also felt that lcons
> (construct) and nconc(concat) were too similarly named.

I think nconc is a direct copy from the Lisp original; whatever its
origins are, they're back in Lisp prehistory.  I don't mind renaming
that one ;-)

Let's see ... fleshing out this idea a bit, here's a rundown of all the
symbols in pg_list.h and suggested new names:

ListCell accessors:

lfirst		no change
lfirsti		lfirst_int
lfirsto		lfirst_oid
lnext		no change
foreach		no change

List accessors:

length		no change

lfirstcell	new function to get first cell, or NULL if none

lfirst		rewrite as lfirst(lfirstcell()) when applied to a List

lsecond, lthird, lfourth	not clear if worth keeping

llastnode	llastcell

llast		Perhaps rewrite as lfirst(llastcell()) instead of keeping

makeListN	list_makeN or possibly list_make_N
makeListiN	list_makeN_int or list_make_N_int
makeListoN	list_makeN_oid or list_make_N_oid

lcons		no change
lconsi		lcons_int
lconso		lcons_oid

lappend		no change
lappendi	lappend_int
lappendo	lappend_oid

nconc		list_concat
We might also need a function to attach some bare ListCells to a List

nth		list_nth
		list_nth_int
		list_nth_oid
Should add list_nth_int, list_nth_oid, even though there are no
corresponding functions at the moment

member		list_member
ptrMember	list_member_ptr
intMember	list_member_int
oidMember	list_member_oid

LispRemove	list_remove
lremove		list_remove_ptr
lremovei	list_remove_int
		list_remove_oid		add, though not currently used

ltruncate	list_truncate

set_union	list_union
set_ptrUnion	list_union_ptr
		list_union_int		not currently used
set_uniono	list_union_oid

set_difference	list_difference
set_ptrDifference  list_difference_ptr
		list_difference_int	not currently used
set_differenceo	list_difference_oid

equali and equalo become just calls on equal()

freeList	list_free  (frees only List, not pointed-to objects)

listCopy	list_copy  (shallow copy of List only)

A couple of notes here: I propose using the suffix "_ptr" for operations
that use pointer equality rather than equal().  Neil proposed "_simple"
but that seems less than clear to me --- which one is "simple" and which
isn't?  Also, for the "set" operations I have just "list_union" etc
where Neil proposed "list_set_union".

Neil proposed inventing "list_deep_copy" which as far as I can see is
entirely redundant with copyObject.  Similarly I can't see any value in
list_equal when equal() will do the trick.

			regards, tom lane