Require that array literals produce "rectangular" arrays, i.e. all the

subarrays of a given dimension have the same number of elements/subarrays.

Also repair a longstanding undocumented (as far as I can see) ability to
explicitly set array bounds in the array literal syntax. It now can
deal properly with negative array indicies. Modify array_out so that
arrays with non-standard lower bounds (i.e. not 1) are output with
the expicit dimension syntax. This fixes a longstanding issue whereby
arrays with non-default lower bounds had them changed to default
after a dump/reload cycle.

Modify regression tests and docs to suit, and add some minimal
documentation regarding the explicit dimension syntax.

doc/src/sgml/array.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.35 2004/06/07 04:04:47 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.36 2004/08/05 03:29:11 joe Exp $ -->
 
 <sect1 id="arrays">
  <title>Arrays</title>
@@ -121,12 +121,23 @@ CREATE TABLE tictactoe (
 INSERT INTO sal_emp
     VALUES ('Bill',
     '{10000, 10000, 10000, 10000}',
-    '{{"meeting", "lunch"}, {}}');
+    '{{"meeting", "lunch"}, {"meeting"}}');
+ERROR:  multidimensional arrays must have array expressions with matching dimensions
+</programlisting>
+
+  Note that multidimensional arrays must have matching extents for each
+  dimension. A mismatch causes an error report.
+
+<programlisting>
+INSERT INTO sal_emp
+    VALUES ('Bill',
+    '{10000, 10000, 10000, 10000}',
+    '{{"meeting", "lunch"}, {"training", "presentation"}}');
 
 INSERT INTO sal_emp
     VALUES ('Carol',
     '{20000, 25000, 25000, 25000}',
-    '{{"talk", "consult"}, {"meeting"}}');
+    '{{"breakfast", "consulting"}, {"meeting", "lunch"}}');
 </programlisting>
   </para>
 
@@ -138,59 +149,31 @@ INSERT INTO sal_emp
   </para>
 
  <para>
-  This can lead to surprising results. For example, the result of the
-  previous two inserts looks like this:
+  The result of the previous two inserts looks like this:
 <programlisting>
 SELECT * FROM sal_emp;
  name  |      pay_by_quarter       |                 schedule
--------+---------------------------+--------------------
- Bill  | {10000,10000,10000,10000} | {{meeting},{""}}
- Carol | {20000,25000,25000,25000} | {{talk},{meeting}}
+-------+---------------------------+-------------------------------------------
+ Bill  | {10000,10000,10000,10000} | {{meeting,lunch},{training,presentation}}
+ Carol | {20000,25000,25000,25000} | {{breakfast,consulting},{meeting,lunch}}
 (2 rows)
 </programlisting>
-  Because the <literal>[2][2]</literal> element of
-  <structfield>schedule</structfield> is missing in each of the
-  <command>INSERT</command> statements, the <literal>[1][2]</literal>
-  element is discarded.
  </para>
 
- <note>
-  <para>
-   Fixing this is on the to-do list.
-  </para>
- </note>
-
  <para>
   The <literal>ARRAY</literal> expression syntax may also be used:
 <programlisting>
 INSERT INTO sal_emp
     VALUES ('Bill',
     ARRAY[10000, 10000, 10000, 10000],
-    ARRAY[['meeting', 'lunch'], ['','']]);
+    ARRAY[['meeting', 'lunch'], ['training', 'presentation']]);
 
 INSERT INTO sal_emp
     VALUES ('Carol',
     ARRAY[20000, 25000, 25000, 25000],
-    ARRAY[['talk', 'consult'], ['meeting', '']]);
-SELECT * FROM sal_emp;
- name  |      pay_by_quarter       |           schedule
--------+---------------------------+-------------------------------
- Bill  | {10000,10000,10000,10000} | {{meeting,lunch},{"",""}}
- Carol | {20000,25000,25000,25000} | {{talk,consult},{meeting,""}}
-(2 rows)
-</programlisting>
-  Note that with this syntax, multidimensional arrays must have matching
-  extents for each dimension. A mismatch causes an error report, rather than
-  silently discarding values as in the previous case.
-  For example:
-<programlisting>
-INSERT INTO sal_emp
-    VALUES ('Carol',
-    ARRAY[20000, 25000, 25000, 25000],
-    ARRAY[['talk', 'consult'], ['meeting']]);
-ERROR:  multidimensional arrays must have array expressions with matching dimensions
+    ARRAY[['breakfast', 'consulting'], ['meeting', 'lunch']]);
 </programlisting>
-  Also notice that the array elements are ordinary SQL constants or
+  Notice that the array elements are ordinary SQL constants or
   expressions; for instance, string literals are single quoted, instead of
   double quoted as they would be in an array literal.  The <literal>ARRAY</>
   expression syntax is discussed in more detail in <xref
@@ -248,8 +231,8 @@ SELECT pay_by_quarter[3] FROM sal_emp;
 SELECT schedule[1:2][1:1] FROM sal_emp WHERE name = 'Bill';
 
         schedule
---------------------
- {{meeting},{""}}
+------------------------
+ {{meeting},{training}}
 (1 row)
 </programlisting>
 
@@ -266,9 +249,10 @@ SELECT schedule[1:2][1] FROM sal_emp WHERE name = 'Bill';
   is specified, as in this example:
 <programlisting>
 SELECT schedule[1:2][2] FROM sal_emp WHERE name = 'Bill';
+
                  schedule
----------------------------
- {{meeting,lunch},{"",""}}
+-------------------------------------------
+ {{meeting,lunch},{training,presentation}}
 (1 row)
 </programlisting>
  </para>
@@ -546,6 +530,47 @@ SELECT * FROM sal_emp WHERE 10000 = ALL (pay_by_quarter);
    up to the next right brace or delimiter is taken as the item value.
   </para>
 
+  <para>
+   By default, the lower bound index value of an array's dimensions is
+   set to one. If any of an array's dimensions has a lower bound index not
+   equal to one, an additional decoration that indicates the actual
+   array dimensions will precede the array structure decoration.
+   The decoration consists of square braces (<literal>[</> and <literal>]</>)
+   around each array dimension's lower and upper bound indicies, plus
+   a colon (<literal>:</>) delimiter character inbetween. Delimiting the
+   array dimension decoration from the array structure decoration is a
+   single assignment operator (<literal>=</>). For example:
+<programlisting>
+SELECT 1 || ARRAY[2,3] AS array;
+
+     array
+---------------
+ [0:2]={1,2,3}
+(1 row)
+
+SELECT ARRAY[1,2] || ARRAY[[3,4]] AS array;
+
+          array
+--------------------------
+ [0:1][1:2]={{1,2},{3,4}}
+(1 row)
+</programlisting>
+  </para>
+
+  <para>
+   In a similar fashion, an array with non-default indicies may be specified
+   using the same literal syntax. For example:
+<programlisting>
+SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2
+ FROM (SELECT '[1:1][-2:-1][3:5]={{{1,2,3},{4,5,6}}}'::int[] AS f1) AS ss;
+
+ e1 | e2
+----+----
+  1 |  6
+(1 row)
+</programlisting>
+  </para>
+
   <para>
    As shown previously, when writing an array value you may write double
    quotes around any individual array

src/backend/utils/adt/arrayfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.105 2004/06/16 01:26:47 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.106 2004/08/05 03:29:37 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -217,7 +217,7 @@ array_in(PG_FUNCTION_ARGS)
 					 errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)",
 							ndim, MAXDIM)));
 
-		for (q = p; isdigit((unsigned char) *q); q++);
+		for (q = p; isdigit((unsigned char) *q) || (*q == '-') || (*q == '+'); q++);
 		if (q == p)				/* no digits? */
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -229,7 +229,7 @@ array_in(PG_FUNCTION_ARGS)
 			*q = '\0';
 			lBound[ndim] = atoi(p);
 			p = q + 1;
-			for (q = p; isdigit((unsigned char) *q); q++);
+			for (q = p; isdigit((unsigned char) *q) || (*q == '-') || (*q == '+'); q++);
 			if (q == p)			/* no digits? */
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -270,6 +270,9 @@ array_in(PG_FUNCTION_ARGS)
 	}
 	else
 	{
+		int			ndim_braces,
+					dim_braces[MAXDIM];
+
 		/* If array dimensions are given, expect '=' operator */
 		if (strncmp(p, ASSGN, strlen(ASSGN)) != 0)
 			ereport(ERROR,
@@ -278,6 +281,27 @@ array_in(PG_FUNCTION_ARGS)
 		p += strlen(ASSGN);
 		while (isspace((unsigned char) *p))
 			p++;
+
+		/*
+		 * intuit dimensions from brace structure -- it better match what
+		 * we were given
+		 */
+		if (*p != '{')
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("array value must start with \"{\" or dimension information")));
+		ndim_braces = ArrayCount(p, dim_braces, typdelim);
+		if (ndim_braces != ndim)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("array dimensions incompatible with array literal")));
+		for (i = 0; i < ndim; ++i)
+		{
+			if (dim[i] != dim_braces[i])
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+						errmsg("array dimensions incompatible with array literal")));
+		}
 	}
 
 #ifdef ARRAYDEBUG
@@ -303,7 +327,6 @@ array_in(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("missing left brace")));
-
 	dataPtr = ReadArrayStr(p, nitems, ndim, dim, &my_extra->proc, typioparam,
 						   typmod, typdelim, typlen, typbyval, typalign,
 						   &nbytes);
@@ -334,13 +357,18 @@ ArrayCount(char *str, int *dim, char typdelim)
 	int			nest_level = 0,
 				i;
 	int			ndim = 1,
-				temp[MAXDIM];
+				temp[MAXDIM],
+				nelems[MAXDIM],
+				nelems_last[MAXDIM];
 	bool		scanning_string = false;
 	bool		eoArray = false;
 	char	   *ptr;
 
 	for (i = 0; i < MAXDIM; ++i)
+	{
 		temp[i] = dim[i] = 0;
+		nelems_last[i] = nelems[i] = 1;
+	}
 
 	if (strncmp(str, "{}", 2) == 0)
 		return 0;
@@ -394,6 +422,16 @@ ArrayCount(char *str, int *dim, char typdelim)
 							(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 							 errmsg("malformed array literal: \"%s\"", str)));
 						nest_level--;
+
+						if ((nelems_last[nest_level] != 1) &&
+							(nelems[nest_level] != nelems_last[nest_level]))
+							ereport(ERROR,
+								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+								 errmsg("multidimensional arrays must have "
+										"array expressions with matching "
+										"dimensions")));
+						nelems_last[nest_level] = nelems[nest_level];
+						nelems[nest_level] = 1;
 						if (nest_level == 0)
 							eoArray = itemdone = true;
 						else
@@ -408,7 +446,10 @@ ArrayCount(char *str, int *dim, char typdelim)
 					break;
 				default:
 					if (*ptr == typdelim && !scanning_string)
+					{
 						itemdone = true;
+						nelems[nest_level - 1]++;
+					}
 					break;
 			}
 			if (!itemdone)
@@ -684,8 +725,15 @@ array_out(PG_FUNCTION_ARGS)
 	char	   *p,
 			   *tmp,
 			   *retval,
-			  **values;
-	bool	   *needquotes;
+			  **values,
+				/*
+				 * 33 per dim since we assume 15 digits per number + ':' +'[]'
+				 *
+				 * +2 allows for assignment operator + trailing null
+				 */
+				dims_str[(MAXDIM * 33) + 2];
+	bool	   *needquotes,
+				needdims = false;
 	int			nitems,
 				overall_length,
 				i,
@@ -693,7 +741,8 @@ array_out(PG_FUNCTION_ARGS)
 				k,
 				indx[MAXDIM];
 	int			ndim,
-			   *dim;
+			   *dim,
+			   *lb;
 	ArrayMetaState *my_extra;
 
 	element_type = ARR_ELEMTYPE(v);
@@ -734,6 +783,7 @@ array_out(PG_FUNCTION_ARGS)
 
 	ndim = ARR_NDIM(v);
 	dim = ARR_DIMS(v);
+	lb = ARR_LBOUND(v);
 	nitems = ArrayGetNItems(ndim, dim);
 
 	if (nitems == 0)
@@ -742,6 +792,19 @@ array_out(PG_FUNCTION_ARGS)
 		PG_RETURN_CSTRING(retval);
 	}
 
+	/*
+	 * we will need to add explicit dimensions if any dimension
+	 * has a lower bound other than one
+	 */
+	for (i = 0; i < ndim; i++)
+	{
+		if (lb[i] != 1)
+		{
+			needdims = true;
+			break;
+		}
+	}
+
 	/*
 	 * Convert all values to string form, count total space needed
 	 * (including any overhead such as escaping backslashes), and detect
@@ -798,12 +861,28 @@ array_out(PG_FUNCTION_ARGS)
 	 */
 	for (i = j = 0, k = 1; i < ndim; k *= dim[i++], j += k);
 
-	retval = (char *) palloc(overall_length + 2 * j);
+	/* add explicit dimensions if required */
+	if (needdims)
+	{
+		char   *ptr = dims_str;
+
+		for (i = 0; i < ndim; i++)
+		{
+			sprintf(ptr, "[%d:%d]", lb[i], lb[i] + dim[i] - 1);
+			ptr += strlen(ptr);
+		}
+		*ptr++ = *ASSGN;
+		*ptr = '\0';
+	}
+
+	retval = (char *) palloc(strlen(dims_str) + overall_length + 2 * j);
 	p = retval;
 
 #define APPENDSTR(str)	(strcpy(p, (str)), p += strlen(p))
 #define APPENDCHAR(ch)	(*p++ = (ch), *p = '\0')
 
+	if (needdims)
+		APPENDSTR(dims_str);
 	APPENDCHAR('{');
 	for (i = 0; i < ndim; indx[i++] = 0);
 	j = 0;

src/test/regress/expected/arrays.out

@@ -28,8 +28,8 @@ INSERT INTO arrtest (a, b[1:2], c, d[1:2])
    VALUES ('{}', '{3,4}', '{foo,bar}', '{bar,foo}');
 SELECT * FROM arrtest;
       a      |        b        |     c     |       d       |        e        |        f        |      g      
--------------+-----------------+-----------+---------------+-----------+-----------------+-------------
- {1,2,3,4,5} | {{{0,0},{1,2}}} | {}        | {}            | {1.1,2.2} | {}              | {}
+-------------+-----------------+-----------+---------------+-----------------+-----------------+-------------
+ {1,2,3,4,5} | {{{0,0},{1,2}}} | {}        | {}            | [0:1]={1.1,2.2} | {}              | {}
  {11,12,23}  | {{3,4},{4,5}}   | {foobar}  | {{elt1,elt2}} | {3.4,6.7}       | {"abc  ",abcde} | {abc,abcde}
  {}          | {3,4}           | {foo,bar} | {bar,foo}     |                 |                 | 
 (3 rows)
@@ -185,8 +185,8 @@ SELECT array_append(array[42], 6) AS "{42,6}";
 
 SELECT array_prepend(6, array[42]) AS "{6,42}";
     {6,42}    
---------
- {6,42}
+--------------
+ [0:1]={6,42}
 (1 row)
 
 SELECT array_cat(ARRAY[1,2], ARRAY[3,4]) AS "{1,2,3,4}";
@@ -197,8 +197,8 @@ SELECT array_cat(ARRAY[1,2], ARRAY[3,4]) AS "{1,2,3,4}";
 
 SELECT array_cat(ARRAY[1,2], ARRAY[[3,4],[5,6]]) AS "{{1,2},{3,4},{5,6}}";
       {{1,2},{3,4},{5,6}}       
----------------------
- {{1,2},{3,4},{5,6}}
+--------------------------------
+ [0:2][1:2]={{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}}";
@@ -228,8 +228,8 @@ SELECT ARRAY[1,2] || 3 AS "{1,2,3}";
 
 SELECT 0 || ARRAY[1,2] AS "{0,1,2}";
     {0,1,2}    
----------
- {0,1,2}
+---------------
+ [0:2]={0,1,2}
 (1 row)
 
 SELECT ARRAY[1,2] || ARRAY[3,4] AS "{1,2,3,4}";
@@ -258,8 +258,8 @@ SELECT ARRAY[0,0] || ARRAY[1,1] || ARRAY[2,2] AS "{0,0,1,1,2,2}";
 
 SELECT 0 || ARRAY[1,2] || 3 AS "{0,1,2,3}";
     {0,1,2,3}    
------------
- {0,1,2,3}
+-----------------
+ [0:3]={0,1,2,3}
 (1 row)
 
 -- array casts

src/test/regress/expected/domain.out

@@ -72,29 +72,29 @@ create table domarrtest
            ( testint4arr domainint4arr
            , testtextarr domaintextarr
             );
-INSERT INTO domarrtest values ('{2,2}', '{{"a","b"}{"c","d"}}');
-INSERT INTO domarrtest values ('{{2,2}{2,2}}', '{{"a","b"}}');
-INSERT INTO domarrtest values ('{2,2}', '{{"a","b"}{"c","d"}{"e"}}');
-INSERT INTO domarrtest values ('{2,2}', '{{"a"}{"c"}}');
-INSERT INTO domarrtest values (NULL, '{{"a","b"}{"c","d","e"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a","b"},{"c","d"}}');
+INSERT INTO domarrtest values ('{{2,2},{2,2}}', '{{"a","b"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a","b"},{"c","d"},{"e","f"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a"},{"c"}}');
+INSERT INTO domarrtest values (NULL, '{{"a","b","c"},{"d","e","f"}}');
 select * from domarrtest;
   testint4arr  |     testtextarr     
 ---------------+---------------------
- {2,2}         | {{a,c},{"",d}}
- {{2,2},{0,2}} | {{a,b}}
- {2,2}         | {{a},{c},{e}}
- {2,2}         | {{c},{""}}
-               | {{a,c,""},{"",d,e}}
+ {2,2}         | {{a,b},{c,d}}
+ {{2,2},{2,2}} | {{a,b}}
+ {2,2}         | {{a,b},{c,d},{e,f}}
+ {2,2}         | {{a},{c}}
+               | {{a,b,c},{d,e,f}}
 (5 rows)
 
 select testint4arr[1], testtextarr[2:2] from domarrtest;
  testint4arr | testtextarr 
 -------------+-------------
-           2 | {{"",d}}
+           2 | {{c,d}}
              | 
+           2 | {{c,d}}
            2 | {{c}}
-           2 | {{""}}
-             | {{"",d,e}}
+             | {{d,e,f}}
 (5 rows)
 
 drop table domarrtest;

src/test/regress/sql/domain.sql

@@ -66,11 +66,11 @@ create table domarrtest
            ( testint4arr domainint4arr
            , testtextarr domaintextarr
             );
-INSERT INTO domarrtest values ('{2,2}', '{{"a","b"}{"c","d"}}');
-INSERT INTO domarrtest values ('{{2,2}{2,2}}', '{{"a","b"}}');
-INSERT INTO domarrtest values ('{2,2}', '{{"a","b"}{"c","d"}{"e"}}');
-INSERT INTO domarrtest values ('{2,2}', '{{"a"}{"c"}}');
-INSERT INTO domarrtest values (NULL, '{{"a","b"}{"c","d","e"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a","b"},{"c","d"}}');
+INSERT INTO domarrtest values ('{{2,2},{2,2}}', '{{"a","b"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a","b"},{"c","d"},{"e","f"}}');
+INSERT INTO domarrtest values ('{2,2}', '{{"a"},{"c"}}');
+INSERT INTO domarrtest values (NULL, '{{"a","b","c"},{"d","e","f"}}');
 select * from domarrtest;
 select testint4arr[1], testtextarr[2:2] from domarrtest;