From 1e9a1a70adc1f36d9ba8cd67ce974f777df7aafb Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 19 Nov 2005 01:50:08 +0000 Subject: [PATCH] Change array_push and array_cat so that they retain the lower bound of the array (for array_push) or higher-dimensional array (for array_cat) rather than decrementing it as before. This avoids generating lower bounds other than one for any array operation within the SQL spec. Per recent discussion. Interestingly, this seems to have been the original behavior, because while updating the docs I noticed that a large fraction of relevant examples were *wrong* for the old behavior and are now right. Is it worth correcting this in the back-branch docs? --- doc/src/sgml/array.sgml | 14 ++++++-------- doc/src/sgml/func.sgml | 4 ++-- src/backend/utils/adt/array_userfuncs.c | 14 +++++++++----- src/test/regress/expected/arrays.out | 24 ++++++++++++------------ 4 files changed, 29 insertions(+), 27 deletions(-) diff --git a/doc/src/sgml/array.sgml b/doc/src/sgml/array.sgml index c24646e43c..9255144999 100644 --- a/doc/src/sgml/array.sgml +++ b/doc/src/sgml/array.sgml @@ -1,4 +1,4 @@ - + Arrays @@ -391,13 +391,11 @@ SELECT ARRAY[5,6] || ARRAY[[1,2],[3,4]]; - When a single element is pushed on to the beginning of a one-dimensional - array, the result is an array with a lower bound subscript equal to - the right-hand operand's lower bound subscript, minus one. When a single - element is pushed on to the end of a one-dimensional array, the result is - an array retaining the lower bound of the left-hand operand. For example: + When a single element is pushed on to either the beginning or end of a + one-dimensional array, the result is an array with the same lower bound + subscript as the array operand. For example: -SELECT array_dims(1 || ARRAY[2,3]); +SELECT array_dims(1 || '[0:1]={2,3}'::int[]); array_dims ------------ [0:2] @@ -441,7 +439,7 @@ SELECT array_dims(ARRAY[[1,2],[3,4]] || ARRAY[[5,6],[7,8],[9,0]]); SELECT array_dims(ARRAY[1,2] || ARRAY[[3,4],[5,6]]); array_dims ------------ - [0:2][1:2] + [1:3][1:2] (1 row) diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 8bc963b02f..c0e364a30b 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,5 +1,5 @@ @@ -7484,7 +7484,7 @@ SELECT NULLIF(value, '(none)') ... int returns lower bound of the requested array dimension - array_lower(array_prepend(0, ARRAY[1,2,3]), 1) + array_lower('[0:2]={1,2,3}'::int[], 1) 0 diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c index 468e444e13..e1fc3f26db 100644 --- a/src/backend/utils/adt/array_userfuncs.c +++ b/src/backend/utils/adt/array_userfuncs.c @@ -6,7 +6,7 @@ * Copyright (c) 2003-2005, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/array_userfuncs.c,v 1.17 2005/11/17 22:14:52 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/array_userfuncs.c,v 1.18 2005/11/19 01:50:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -152,6 +152,13 @@ array_push(PG_FUNCTION_ARGS) result = array_set(v, 1, &indx, newelem, isNull, -1, typlen, typbyval, typalign); + /* + * Readjust result's LB to match the input's. This does nothing in the + * append case, but it's the simplest way to implement the prepend case. + */ + if (ARR_NDIM(v) == 1) + ARR_LBOUND(result)[0] = ARR_LBOUND(v)[0]; + PG_RETURN_ARRAYTYPE_P(result); } @@ -305,7 +312,7 @@ array_cat(PG_FUNCTION_ARGS) { /* * resulting array has the second argument as the outer array, with - * the first argument appended to the front of the outer dimension + * the first argument inserted at the front of the outer dimension */ ndims = ndims2; dims = (int *) palloc(ndims * sizeof(int)); @@ -316,9 +323,6 @@ array_cat(PG_FUNCTION_ARGS) /* increment number of elements in outer array */ dims[0] += 1; - /* decrement outer array lower bound */ - lbs[0] -= 1; - /* make sure the added element matches our existing elements */ for (i = 0; i < ndims1; i++) { diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out index da218f0047..11b83ea993 100644 --- a/src/test/regress/expected/arrays.out +++ b/src/test/regress/expected/arrays.out @@ -224,9 +224,9 @@ SELECT array_append(array[42], 6) AS "{42,6}"; (1 row) SELECT array_prepend(6, array[42]) AS "{6,42}"; - {6,42} --------------- - [0:1]={6,42} + {6,42} +-------- + {6,42} (1 row) SELECT array_cat(ARRAY[1,2], ARRAY[3,4]) AS "{1,2,3,4}"; @@ -236,9 +236,9 @@ SELECT array_cat(ARRAY[1,2], ARRAY[3,4]) AS "{1,2,3,4}"; (1 row) SELECT array_cat(ARRAY[1,2], ARRAY[[3,4],[5,6]]) AS "{{1,2},{3,4},{5,6}}"; - {{1,2},{3,4},{5,6}} --------------------------------- - [0:2][1:2]={{1,2},{3,4},{5,6}} + {{1,2},{3,4},{5,6}} +--------------------- + {{1,2},{3,4},{5,6}} (1 row) SELECT array_cat(ARRAY[[3,4],[5,6]], ARRAY[1,2]) AS "{{3,4},{5,6},{1,2}}"; @@ -267,9 +267,9 @@ SELECT ARRAY[1,2] || 3 AS "{1,2,3}"; (1 row) SELECT 0 || ARRAY[1,2] AS "{0,1,2}"; - {0,1,2} ---------------- - [0:2]={0,1,2} + {0,1,2} +--------- + {0,1,2} (1 row) SELECT ARRAY[1,2] || ARRAY[3,4] AS "{1,2,3,4}"; @@ -297,9 +297,9 @@ SELECT ARRAY[0,0] || ARRAY[1,1] || ARRAY[2,2] AS "{0,0,1,1,2,2}"; (1 row) SELECT 0 || ARRAY[1,2] || 3 AS "{0,1,2,3}"; - {0,1,2,3} ------------------ - [0:3]={0,1,2,3} + {0,1,2,3} +----------- + {0,1,2,3} (1 row) -- array casts