Change array_offset to return subscripts, not offsets

... and rename it and its sibling array_offsets to array_position and
array_positions, to account for the changed behavior.

Having the functions return subscripts better matches existing practice,
and is better suited to using the result value as a subscript into the
array directly.  For one-based arrays, the new definition is identical
to what was originally committed.

(We use the term "subscript" in the documentation, which is what we use
whenever we talk about arrays; but the functions themselves are named
using the word "position" to match the standard-defined POSITION()
functions.)

Author: Pavel Stěhule
Behavioral problem noted by Dean Rasheed.

3 files changed, 7 insertions, 7 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 0fde1d6ec6d..b87d080c692 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201503301
+#define CATALOG_VERSION_NO	201503302
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 3cd7851c4ac..8890ade7edf 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -895,11 +895,11 @@ DATA(insert OID = 515 (  array_larger	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2
 DESCR("larger of two");
 DATA(insert OID = 516 (  array_smaller	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_smaller _null_ _null_ _null_ ));
 DESCR("smaller of two");
-DATA(insert OID = 3277 (  array_offset		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 23 "2277 2283" _null_ _null_ _null_ _null_ array_offset _null_ _null_ _null_ ));
+DATA(insert OID = 3277 (  array_position		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 23 "2277 2283" _null_ _null_ _null_ _null_ array_position _null_ _null_ _null_ ));
 DESCR("returns a offset of value in array");
-DATA(insert OID = 3278 (  array_offset		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 23 "2277 2283 23" _null_ _null_ _null_ _null_ array_offset_start _null_ _null_ _null_ ));
+DATA(insert OID = 3278 (  array_position		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 23 "2277 2283 23" _null_ _null_ _null_ _null_ array_position_start _null_ _null_ _null_ ));
 DESCR("returns a offset of value in array with start index");
-DATA(insert OID = 3279 (  array_offsets		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 1007 "2277 2283" _null_ _null_ _null_ _null_ array_offsets _null_ _null_ _null_ ));
+DATA(insert OID = 3279 (  array_positions		   PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 1007 "2277 2283" _null_ _null_ _null_ _null_ array_positions _null_ _null_ _null_ ));
 DESCR("returns a array of offsets of some value in array");
 DATA(insert OID = 1191 (  generate_subscripts PGNSP PGUID 12 1 1000 0 0 f f f f t t i 3 0 23 "2277 23 16" _null_ _null_ _null_ _null_ generate_subscripts _null_ _null_ _null_ ));
 DESCR("array subscripts generator");
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index b78b42abddd..0a488e7b0c1 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -358,9 +358,9 @@ extern Datum array_agg_finalfn(PG_FUNCTION_ARGS);
 extern Datum array_agg_array_transfn(PG_FUNCTION_ARGS);
 extern Datum array_agg_array_finalfn(PG_FUNCTION_ARGS);
 
-extern Datum array_offset(PG_FUNCTION_ARGS);
-extern Datum array_offset_start(PG_FUNCTION_ARGS);
-extern Datum array_offsets(PG_FUNCTION_ARGS);
+extern Datum array_position(PG_FUNCTION_ARGS);
+extern Datum array_position_start(PG_FUNCTION_ARGS);
+extern Datum array_positions(PG_FUNCTION_ARGS);
 
 /*
  * prototypes for functions defined in array_typanalyze.c