Add generate_series(numeric, numeric).

Платон Малюгин
Reviewed by Michael Paquier, Ali Akbar and Marti Raudsepp

doc/src/sgml/func.sgml

@@ -14076,8 +14076,8 @@ AND
     <tbody>
      <row>
       <entry><literal><function>generate_series(<parameter>start</parameter>, <parameter>stop</parameter>)</function></literal></entry>
-      <entry><type>int</type> or <type>bigint</type></entry>
+      <entry><type>int</type>, <type>bigint</type> or <type>numeric</type></entry>
-      <entry><type>setof int</type> or <type>setof bigint</type> (same as argument type)</entry>
+      <entry><type>setof int</type>, <type>setof bigint</type>, or <type>setof numeric</type> (same as argument type)</entry>
       <entry>
        Generate a series of values, from <parameter>start</parameter> to <parameter>stop</parameter>
        with a step size of one
@@ -14086,8 +14086,8 @@ AND
 
      <row>
       <entry><literal><function>generate_series(<parameter>start</parameter>, <parameter>stop</parameter>, <parameter>step</parameter>)</function></literal></entry>
-      <entry><type>int</type> or <type>bigint</type></entry>
+      <entry><type>int</type>, <type>bigint</type> or <type>numeric</type></entry>
-      <entry><type>setof int</type> or <type>setof bigint</type> (same as argument type)</entry>
+      <entry><type>setof int</type>, <type>setof bigint</type> or <type>setof numeric</type> (same as argument type)</entry>
       <entry>
        Generate a series of values, from <parameter>start</parameter> to <parameter>stop</parameter>
        with a step size of <parameter>step</parameter>
@@ -14137,6 +14137,14 @@ SELECT * FROM generate_series(4,3);
 -----------------
 (0 rows)
 
+SELECT generate_series(1.1, 4, 1.3);
+ generate_series 
+-----------------
+             1.1
+             2.4
+             3.7
+(3 rows)
+
 -- this example relies on the date-plus-integer operator
 SELECT current_date + s.a AS dates FROM generate_series(0,14,7) AS s(a);
    dates

src/backend/utils/adt/numeric.c

@@ -28,6 +28,7 @@
 
 #include "access/hash.h"
 #include "catalog/pg_type.h"
+#include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
@@ -260,6 +261,18 @@ typedef struct NumericVar
 } NumericVar;
 
 
+/* ----------
+ * Data for generate_series
+ * ----------
+ */
+typedef struct
+{
+	NumericVar	current;
+	NumericVar	stop;
+	NumericVar	step;
+} generate_series_numeric_fctx;
+
+
 /* ----------
  * Some preinitialized constants
  * ----------
@@ -1229,6 +1242,117 @@ numeric_floor(PG_FUNCTION_ARGS)
 	PG_RETURN_NUMERIC(res);
 }
 
+
+/*
+ * generate_series_numeric() -
+ *
+ *  Generate series of numeric.
+ */
+Datum
+generate_series_numeric(PG_FUNCTION_ARGS)
+{
+	return generate_series_step_numeric(fcinfo);
+}
+
+Datum
+generate_series_step_numeric(PG_FUNCTION_ARGS)
+{
+	generate_series_numeric_fctx *fctx;
+	FuncCallContext *funcctx;
+	MemoryContext oldcontext;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		Numeric		start_num = PG_GETARG_NUMERIC(0);
+		Numeric		stop_num = PG_GETARG_NUMERIC(1);
+		NumericVar	steploc = const_one;
+
+		/* handle NaN in start and stop values */
+		if (NUMERIC_IS_NAN(start_num))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("start value cannot be NaN")));
+
+		if (NUMERIC_IS_NAN(stop_num))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("stop value cannot be NaN")));
+
+		/* see if we were given an explicit step size */
+		if (PG_NARGS() == 3)
+		{
+			Numeric	step_num = PG_GETARG_NUMERIC(2);
+
+			if (NUMERIC_IS_NAN(step_num))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("step size cannot be NaN")));
+
+			init_var_from_num(step_num, &steploc);
+
+			if (cmp_var(&steploc, &const_zero) == 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("step size cannot equal zero")));
+		}
+
+		/* create a function context for cross-call persistence */
+		funcctx = SRF_FIRSTCALL_INIT();
+
+		/*
+		 * Switch to memory context appropriate for multiple function calls.
+		 */
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* allocate memory for user context */
+		fctx = (generate_series_numeric_fctx *)
+			palloc(sizeof(generate_series_numeric_fctx));
+
+		/*
+		 * Use fctx to keep state from call to call. Seed current with the
+		 * original start value.
+		 */
+		init_var_from_num(start_num, &fctx->current);
+		init_var_from_num(stop_num, &fctx->stop);
+		init_var(&fctx->step);
+		set_var_from_var(&steploc, &fctx->step);
+
+		funcctx->user_fctx = fctx;
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	/* stuff done on every call of the function */
+	funcctx = SRF_PERCALL_SETUP();
+
+	/*
+	 * Get the saved state and use current state as the result of this
+	 * iteration.
+	 */
+	fctx = funcctx->user_fctx;
+
+	if ((fctx->step.sign == NUMERIC_POS &&
+		 cmp_var(&fctx->current, &fctx->stop) <= 0) ||
+		(fctx->step.sign == NUMERIC_NEG &&
+		 cmp_var(&fctx->current, &fctx->stop) >= 0))
+	{
+		Numeric	result = make_result(&fctx->current);
+
+		/* switch to memory context appropriate for iteration calculation */
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* increment current in preparation for next iteration */
+		add_var(&fctx->current, &fctx->step, &fctx->current);
+		MemoryContextSwitchTo(oldcontext);
+
+		/* do when there is more left to send */
+		SRF_RETURN_NEXT(funcctx, NumericGetDatum(result));
+	}
+	else
+		/* do when there is no more left */
+		SRF_RETURN_DONE(funcctx);
+}
+
+
 /*
  * Implements the numeric version of the width_bucket() function
  * defined by SQL2003. See also width_bucket_float8().

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201411071
+#define CATALOG_VERSION_NO	201411111
 
 #endif

src/include/catalog/pg_proc.h

@@ -3952,6 +3952,10 @@ DATA(insert OID = 1068 (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t
 DESCR("non-persistent series generator");
 DATA(insert OID = 1069 (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t i 2 0 20 "20 20" _null_ _null_ _null_ _null_ generate_series_int8 _null_ _null_ _null_ ));
 DESCR("non-persistent series generator");
+DATA(insert OID = 3259 (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t i 3 0 1700 "1700 1700 1700" _null_ _null_ _null_ _null_ generate_series_step_numeric _null_ _null_ _null_ ));
+DESCR("non-persistent series generator");
+DATA(insert OID = 3260 (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t i 2 0 1700 "1700 1700" _null_ _null_ _null_ _null_ generate_series_numeric _null_ _null_ _null_ ));
+DESCR("non-persistent series generator");
 DATA(insert OID = 938  (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t i 3 0 1114 "1114 1114 1186" _null_ _null_ _null_ _null_ generate_series_timestamp _null_ _null_ _null_ ));
 DESCR("non-persistent series generator");
 DATA(insert OID = 939  (  generate_series PGNSP PGUID 12 1 1000 0 0 f f f f t t s 3 0 1184 "1184 1184 1186" _null_ _null_ _null_ _null_ generate_series_timestamptz _null_ _null_ _null_ ));

src/include/utils/builtins.h

@@ -1029,6 +1029,8 @@ extern Datum int8_avg(PG_FUNCTION_ARGS);
 extern Datum int2int4_sum(PG_FUNCTION_ARGS);
 extern Datum width_bucket_numeric(PG_FUNCTION_ARGS);
 extern Datum hash_numeric(PG_FUNCTION_ARGS);
+extern Datum generate_series_numeric(PG_FUNCTION_ARGS);
+extern Datum generate_series_step_numeric(PG_FUNCTION_ARGS);
 
 /* ri_triggers.c */
 extern Datum RI_FKey_check_ins(PG_FUNCTION_ARGS);

src/test/regress/expected/numeric.out

@@ -1409,3 +1409,55 @@ select 10.0 ^ 2147483647 as overflows;
 ERROR:  value overflows numeric format
 select 117743296169.0 ^ 1000000000 as overflows;
 ERROR:  value overflows numeric format
+--
+-- Tests for generate_series
+--
+select * from generate_series(0.0::numeric, 4.0::numeric);
+ generate_series 
+-----------------
+             0.0
+             1.0
+             2.0
+             3.0
+             4.0
+(5 rows)
+
+select * from generate_series(0.1::numeric, 4.0::numeric, 1.3::numeric);
+ generate_series 
+-----------------
+             0.1
+             1.4
+             2.7
+             4.0
+(4 rows)
+
+select * from generate_series(4.0::numeric, -1.5::numeric, -2.2::numeric);
+ generate_series 
+-----------------
+             4.0
+             1.8
+            -0.4
+(3 rows)
+
+-- Trigger errors
+select * from generate_series(-100::numeric, 100::numeric, 0::numeric);
+ERROR:  step size cannot equal zero
+select * from generate_series(-100::numeric, 100::numeric, 'nan'::numeric);
+ERROR:  step size cannot be NaN
+select * from generate_series('nan'::numeric, 100::numeric, 10::numeric);
+ERROR:  start value cannot be NaN
+select * from generate_series(0::numeric, 'nan'::numeric, 10::numeric);
+ERROR:  stop value cannot be NaN
+-- Checks maximum, output is truncated
+select (i / (10::numeric ^ 131071))::numeric(1,0)
+	from generate_series(6 * (10::numeric ^ 131071),
+			     9 * (10::numeric ^ 131071),
+			     10::numeric ^ 131071) as a(i);
+ numeric 
+---------
+       6
+       7
+       8
+       9
+(4 rows)
+

src/test/regress/sql/numeric.sql

@@ -837,3 +837,20 @@ select 10.0 ^ -2147483648 as rounds_to_zero;
 select 10.0 ^ -2147483647 as rounds_to_zero;
 select 10.0 ^ 2147483647 as overflows;
 select 117743296169.0 ^ 1000000000 as overflows;
+
+--
+-- Tests for generate_series
+--
+select * from generate_series(0.0::numeric, 4.0::numeric);
+select * from generate_series(0.1::numeric, 4.0::numeric, 1.3::numeric);
+select * from generate_series(4.0::numeric, -1.5::numeric, -2.2::numeric);
+-- Trigger errors
+select * from generate_series(-100::numeric, 100::numeric, 0::numeric);
+select * from generate_series(-100::numeric, 100::numeric, 'nan'::numeric);
+select * from generate_series('nan'::numeric, 100::numeric, 10::numeric);
+select * from generate_series(0::numeric, 'nan'::numeric, 10::numeric);
+-- Checks maximum, output is truncated
+select (i / (10::numeric ^ 131071))::numeric(1,0)
+	from generate_series(6 * (10::numeric ^ 131071),
+			     9 * (10::numeric ^ 131071),
+			     10::numeric ^ 131071) as a(i);