plpgsql can assign to subscripted variables now, e.g.

	x[42] := whatever;
The facility is pretty primitive because it doesn't do array slicing and
it has the same semantics as array update in SQL (array must already
be non-null, etc).  But it's a start.

src/pl/plpgsql/src/gram.y

@@ -4,7 +4,7 @@
  *						  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.40 2002/11/10 00:35:58 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.41 2003/03/25 03:16:40 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -105,7 +105,8 @@ static	void check_assignable(PLpgSQL_datum *datum);
 %type <nsitem>	decl_aliasitem
 %type <str>		decl_stmts decl_stmt
 
-%type <expr>	expr_until_semi expr_until_then expr_until_loop
+%type <expr>	expr_until_semi expr_until_rightbracket
+%type <expr>	expr_until_then expr_until_loop
 %type <expr>	opt_exitcond
 
 %type <ival>	assign_var cursor_variable
@@ -822,6 +823,21 @@ assign_var		: T_VARIABLE
 						check_assignable(yylval.variable);
 						$$ = yylval.variable->dno;
 					}
+				| assign_var '[' expr_until_rightbracket
+					{
+						PLpgSQL_arrayelem	*new;
+
+						new = malloc(sizeof(PLpgSQL_arrayelem));
+						memset(new, 0, sizeof(PLpgSQL_arrayelem));
+
+						new->dtype		= PLPGSQL_DTYPE_ARRAYELEM;
+						new->subscript	= $3;
+						new->arrayparentno = $1;
+
+						plpgsql_adddatum((PLpgSQL_datum *)new);
+
+						$$ = new->dno;
+					}
 				;
 
 stmt_if			: K_IF lno expr_until_then proc_sect stmt_else K_END K_IF ';'
@@ -1491,6 +1507,10 @@ expr_until_semi :
 					{ $$ = plpgsql_read_expression(';', ";"); }
 				;
 
+expr_until_rightbracket :
+					{ $$ = plpgsql_read_expression(']', "]"); }
+				;
+
 expr_until_then :
 					{ $$ = plpgsql_read_expression(K_THEN, "THEN"); }
 				;
@@ -1577,16 +1597,16 @@ read_sql_construct(int until,
 	for (;;)
 	{
 		tok = yylex();
-		if (tok == '(')
+		if (tok == until && parenlevel == 0)
+			break;
+		if (tok == '(' || tok == '[')
 			parenlevel++;
-		else if (tok == ')')
+		else if (tok == ')' || tok == ']')
 		{
 			parenlevel--;
 			if (parenlevel < 0)
 				elog(ERROR, "mismatched parentheses");
 		}
-		else if (parenlevel == 0 && tok == until)
-			break;
 		/*
 		 * End of function definition is an error, and we don't expect to
 		 * hit a semicolon either (unless it's the until symbol, in which
@@ -1988,6 +2008,9 @@ check_assignable(PLpgSQL_datum *datum)
 		case PLPGSQL_DTYPE_RECFIELD:
 			/* always assignable? */
 			break;
+		case PLPGSQL_DTYPE_ARRAYELEM:
+			/* always assignable? */
+			break;
 		case PLPGSQL_DTYPE_TRIGARG:
 			yyerror("cannot assign to tg_argv");
 			break;

src/pl/plpgsql/src/pl_funcs.c

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.24 2003/03/25 00:34:23 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.25 2003/03/25 03:16:41 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1023,6 +1023,12 @@ plpgsql_dumptree(PLpgSQL_function * func)
 					   ((PLpgSQL_recfield *) d)->fieldname,
 					   ((PLpgSQL_recfield *) d)->recparentno);
 				break;
+			case PLPGSQL_DTYPE_ARRAYELEM:
+				printf("ARRAYELEM of VAR %d subscript ", 
+					   ((PLpgSQL_arrayelem *) d)->arrayparentno);
+				dump_expr(((PLpgSQL_arrayelem *) d)->subscript);
+				printf("\n");
+				break;
 			case PLPGSQL_DTYPE_TRIGARG:
 				printf("TRIGARG ");
 				dump_expr(((PLpgSQL_trigarg *) d)->argnum);

src/pl/plpgsql/src/plpgsql.h

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.32 2003/03/25 00:34:24 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.33 2003/03/25 03:16:41 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -72,6 +72,7 @@ enum
 	PLPGSQL_DTYPE_ROW,
 	PLPGSQL_DTYPE_REC,
 	PLPGSQL_DTYPE_RECFIELD,
+	PLPGSQL_DTYPE_ARRAYELEM,
 	PLPGSQL_DTYPE_EXPR,
 	PLPGSQL_DTYPE_TRIGARG
 };
@@ -154,7 +155,8 @@ typedef struct
 
 /*
  * PLpgSQL_datum is the common supertype for PLpgSQL_expr, PLpgSQL_var,
- * PLpgSQL_row, PLpgSQL_rec, PLpgSQL_recfield, PLpgSQL_trigarg
+ * PLpgSQL_row, PLpgSQL_rec, PLpgSQL_recfield, PLpgSQL_arrayelem, and
+ * PLpgSQL_trigarg
  */
 typedef struct
 {								/* Generic datum array item		*/
@@ -231,10 +233,19 @@ typedef struct
 	int			dtype;
 	int			rfno;
 	char	   *fieldname;
-	int			recparentno;	/* recno of parent record */
+	int			recparentno;	/* dno of parent record */
 }	PLpgSQL_recfield;
 
 
+typedef struct
+{								/* Element of array variable */
+	int			dtype;
+	int			dno;
+	PLpgSQL_expr *subscript;
+	int			arrayparentno;	/* dno of parent array variable */
+}	PLpgSQL_arrayelem;
+
+
 typedef struct
 {								/* Positional argument to trigger	*/
 	int			dtype;