Skip to content

Commit 6488275

Browse files
bmomjianbmomjian
committed
In developer's FAQ, update list API, from Tom Lane.
1 parent 1b57f0e commit 6488275

File tree

2 files changed

+41
-39
lines changed

2 files changed

+41
-39
lines changed

‎doc/FAQ_DEV

Lines changed: 21 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,7 @@
11

22
Developer's Frequently Asked Questions (FAQ) for PostgreSQL
33

4-
Last updated: Sat May 5 00:09:15 EDT 2007
4+
Last updated: Sat May 5 06:20:41 EDT 2007
55

66
Current maintainer: Bruce Momjian (bruce@momjian.us)
77

@@ -698,20 +698,21 @@ typedef struct nameData
698698
Here are some of the List manipulation commands:
699699

700700
lfirst(i), lfirst_int(i), lfirst_oid(i)
701-
return the data (a point, integer and OID respectively) at list
702-
element i.
701+
return the data (a pointer, integer or OID respectively) of
702+
list cell i.
703703

704704
lnext(i)
705-
return the next list element after i.
705+
return the next list cell after i.
706706

707707
foreach(i, list)
708-
loop through list, assigning each list element to i. It is
709-
important to note that i is a List *, not the data in the List
710-
element. You need to use lfirst(i) to get at the data. Here is
711-
a typical code snippet that loops through a List containing Var
712-
*'s and processes each one:
708+
loop through list, assigning each list cell to i. It is
709+
important to note that i is a ListCell *, not the data in the
710+
List element. You need to use lfirst(i) to get at the data.
711+
Here is a typical code snippet that loops through a List
712+
containing Var *'s and processes each one:
713713

714-
List *list;
714+
715+
List *list;
715716
ListCell *i;
716717

717718
foreach(i, list)
@@ -726,20 +727,20 @@ typedef struct nameData
726727
if list is NIL.
727728

728729
lappend(list, node)
729-
add node to the end of list. This is more expensive that lcons.
730+
add node to the end of list.
730731

731-
nconc(list1, list2)
732-
Concat list2 on to the end of list1.
732+
list_concat(list1, list2)
733+
Concatenate list2 on to the end of list1.
733734

734-
length(list)
735+
list_length(list)
735736
return the length of the list.
736737

737-
nth(i, list)
738-
return the i'th element in list.
738+
list_nth(list, i)
739+
return the i'th element in list, counting from zero.
739740

740-
lconsi, ...
741-
There are integer versions of these: lconsi, lappendi, etc.
742-
Also versions for OID lists: lconso, lappendo, etc.
741+
lcons_int, ...
742+
There are integer versions of these: lcons_int, lappend_int,
743+
etc. Also versions for OID lists: lcons_oid, lappend_oid, etc.
743744

744745
You can print nodes easily inside gdb. First, to disable output
745746
truncation when you use the gdb print command:
@@ -758,7 +759,7 @@ typedef struct nameData
758759

759760
2.4) I just added a field to a structure. What else should I do?
760761

761-
The structures passing around from the parser, rewrite, optimizer, and
762+
The structures passed around in the parser, rewriter, optimizer, and
762763
executor require quite a bit of support. Most structures have support
763764
routines in src/backend/nodes used to create, copy, read, and output
764765
those structures (in particular, the files copyfuncs.c and

‎doc/src/FAQ/FAQ_DEV.html

Lines changed: 20 additions & 19 deletions
Original file line numberDiff line numberDiff line change
@@ -13,7 +13,7 @@
1313
<H1>Developer's Frequently Asked Questions (FAQ) for
1414
PostgreSQL</H1>
1515

16-
<P>Last updated: Sat May 5 00:09:15 EDT 2007</P>
16+
<P>Last updated: Sat May 5 06:20:41 EDT 2007</P>
1717

1818
<P>Current maintainer: Bruce Momjian (<A href=
1919
"mailto:bruce@momjian.us">bruce@momjian.us</A>)<BR>
@@ -863,24 +863,25 @@ <H3 id="item2.3">2.3) Why do we use <I>Node</I> and
863863
<DL>
864864
<DT>lfirst(i), lfirst_int(i), lfirst_oid(i)</DT>
865865

866-
<DD>return the data (a point, integer and OID respectively) at
867-
list element <I>i.</I></DD>
866+
<DD>return the data (a pointer, integer or OID respectively) of
867+
list cell <I>i.</I></DD>
868868

869869
<DT>lnext(i)</DT>
870870

871-
<DD>return the next list element after <I>i.</I></DD>
871+
<DD>return the next list cell after <I>i.</I></DD>
872872

873873
<DT>foreach(i, list)</DT>
874874

875875
<DD>
876-
loop through <I>list,</I> assigning each list element to
877-
<I>i.</I> It is important to note that <I>i</I> is a List *,
876+
loop through <I>list,</I> assigning each list cell to
877+
<I>i.</I> It is important to note that <I>i</I> is a ListCell *,
878878
not the data in the <I>List</I> element. You need to use
879879
<I>lfirst(i)</I> to get at the data. Here is a typical code
880880
snippet that loops through a List containing <I>Var *'s</I>
881881
and processes each one:
882882
<PRE>
883-
<CODE> List *list;
883+
<CODE>
884+
List *list;
884885
ListCell *i;
885886

886887
foreach(i, list)
@@ -900,26 +901,26 @@ <H3 id="item2.3">2.3) Why do we use <I>Node</I> and
900901

901902
<DT>lappend(list, node)</DT>
902903

903-
<DD>add <I>node</I> to the end of <I>list.</I> This is more
904-
expensive that lcons.</DD>
904+
<DD>add <I>node</I> to the end of <I>list.</I></DD>
905905

906-
<DT>nconc(list1, list2)</DT>
906+
<DT>list_concat(list1, list2)</DT>
907907

908-
<DD>Concat <I>list2</I> on to the end of <I>list1.</I></DD>
908+
<DD>Concatenate <I>list2</I> on to the end of <I>list1.</I></DD>
909909

910-
<DT>length(list)</DT>
910+
<DT>list_length(list)</DT>
911911

912912
<DD>return the length of the <I>list.</I></DD>
913913

914-
<DT>nth(i, list)</DT>
914+
<DT>list_nth(list, i)</DT>
915915

916-
<DD>return the <I>i</I>'th element in <I>list.</I></DD>
916+
<DD>return the <I>i</I>'th element in <I>list,</I>
917+
counting from zero.</DD>
917918

918-
<DT>lconsi, ...</DT>
919+
<DT>lcons_int, ...</DT>
919920

920-
<DD>There are integer versions of these: <I>lconsi,
921-
lappendi</I>, etc. Also versions for OID lists: <I>lconso,
922-
lappendo</I>, etc.</DD>
921+
<DD>There are integer versions of these: <I>lcons_int,
922+
lappend_int</I>, etc. Also versions for OID lists: <I>lcons_oid,
923+
lappend_oid</I>, etc.</DD>
923924
</DL>
924925
</BLOCKQUOTE>
925926
You can print nodes easily inside <I>gdb.</I> First, to disable
@@ -944,7 +945,7 @@ <H3 id="item2.3">2.3) Why do we use <I>Node</I> and
944945
<H3 id="item2.4">2.4) I just added a field to a structure.
945946
What else should I do?</H3>
946947

947-
<P>The structures passing around from the parser, rewrite,
948+
<P>The structures passed around in the parser, rewriter,
948949
optimizer, and executor require quite a bit of support. Most
949950
structures have support routines in <I>src/backend/nodes</I> used
950951
to create, copy, read, and output those structures (in particular,

0 commit comments

Comments
 (0)
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy