*** pgsql/src/backend/utils/adt/arrayfuncs.c	2008/04/11 22:52:05	1.143
--- pgsql/src/backend/utils/adt/arrayfuncs.c	2008/04/28 14:48:57	1.144
***************
*** 8,14 ****
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.142 2008/03/25 22:42:43 tgl Exp $
   *
   *-------------------------------------------------------------------------
   */
--- 8,14 ----
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.143 2008/04/11 22:52:05 tgl Exp $
   *
   *-------------------------------------------------------------------------
   */
***************
*** 17,22 ****
--- 17,23 ----
  #include <ctype.h>
  
  #include "access/tupmacs.h"
+ #include "funcapi.h"
  #include "libpq/pqformat.h"
  #include "parser/parse_coerce.h"
  #include "utils/array.h"
*************** array_smaller(PG_FUNCTION_ARGS)
*** 4231,4233 ****
--- 4232,4317 ----
  
  	PG_RETURN_ARRAYTYPE_P(result);
  }
+ 
+ 
+ typedef struct generate_subscripts_fctx
+ {
+         int4    lower;
+         int4    upper;
+         bool    reverse;
+ } generate_subscripts_fctx;
+ 
+ /* 
+  * generate_subscripts(array anyarray, dim int [, reverse bool])
+  *		Returns all subscripts of the array for any dimension
+  */
+ Datum
+ generate_subscripts(PG_FUNCTION_ARGS)
+ {
+ 	FuncCallContext *funcctx;
+ 	MemoryContext oldcontext;
+ 	generate_subscripts_fctx *fctx;
+ 
+ 	/* stuff done only on the first call of the function */
+ 	if (SRF_IS_FIRSTCALL())
+ 	{
+ 		ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
+ 		int		reqdim = PG_GETARG_INT32(1);
+ 		int    *lb,
+ 			   *dimv;
+ 
+ 		/* create a function context for cross-call persistence */
+ 		funcctx = SRF_FIRSTCALL_INIT();
+ 
+ 		/* Sanity check: does it look like an array at all? */
+ 		if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
+ 			SRF_RETURN_DONE(funcctx);
+ 
+ 		/* Sanity check: was the requested dim valid */
+ 		if (reqdim <= 0 || reqdim > ARR_NDIM(v))
+ 			SRF_RETURN_DONE(funcctx);
+ 
+ 		/*
+ 		 * switch to memory context appropriate for multiple function calls
+ 		 */
+ 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+ 		fctx = (generate_subscripts_fctx *) palloc(sizeof(generate_subscripts_fctx));
+ 
+ 		lb = ARR_LBOUND(v);
+ 		dimv = ARR_DIMS(v);
+ 
+ 		fctx->lower = lb[reqdim - 1];
+ 		fctx->upper = dimv[reqdim - 1] + lb[reqdim - 1] - 1;
+ 		fctx->reverse = (PG_NARGS() < 3) ? false : PG_GETARG_BOOL(2);
+ 
+ 		funcctx->user_fctx = fctx;
+ 
+ 		MemoryContextSwitchTo(oldcontext);
+ 	}
+ 
+ 	funcctx = SRF_PERCALL_SETUP();
+ 
+ 	fctx = funcctx->user_fctx;
+ 
+ 	if (fctx->lower <= fctx->upper)
+ 	{
+ 		if (!fctx->reverse)
+ 			SRF_RETURN_NEXT(funcctx, Int32GetDatum(fctx->lower++));
+ 		else
+ 			SRF_RETURN_NEXT(funcctx, Int32GetDatum(fctx->upper--));
+ 	}
+ 	else
+ 		/* done when there are no more elements left */
+ 		SRF_RETURN_DONE(funcctx);
+ }
+ 
+ /*
+  * generate_subscripts_nodir
+  *		Implements the 2-argument version of generate_subscripts
+  */
+ Datum
+ generate_subscripts_nodir(PG_FUNCTION_ARGS)
+ {
+ 	/* just call the other one -- it can handle both cases */
+ 	return generate_subscripts(fcinfo);
+ }