database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-29 10:41:53 +03:00
Code Activity

Attached is a patch implementing factorial(), returning numeric. Points

Browse Source 
to note:

1) arttype is numeric. I thought this was the best way of allowing
arbitarily large factorials, even though factorial(2^63) is a large
number. Happy to change to integers if this is overkill.
2) since we're accepting numeric arguments, the patch tests for floats.
If a numeric is passed with non-zero decimal portion, an error is raised
since (from memory) they are undefined.

Gavin Sherry
This commit is contained in:
Bruce Momjian
2003-12-01 21:52:38 +00:00
parent af03663878
commit 04a4821ade
9 changed files with 74 additions and 100 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
src/backend/utils/adt/int.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/int.c,v 1.58 2003/11/29 19:51:58 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/int.c,v 1.59 2003/12/01 21:52:37 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,7 +26,7 @@
* intpl, intmi, int4mul, intdiv
*
* Arithmetic operators:
* intmod, int4fac
* intmod
*/
#include "postgres.h"
@ -849,40 +849,6 @@ int42mod(PG_FUNCTION_ARGS)
PG_RETURN_INT32(arg1 % arg2);
}
/* int[24]fac()
* Factorial
*/
Datum
int4fac(PG_FUNCTION_ARGS)
{
int32 arg1 = PG_GETARG_INT32(0);
int32 result;
if (arg1 == 0)
result = 1;
else if (arg1 < 0)
result = 0;
else
for (result = 1; arg1 > 0; --arg1)
result *= arg1;
PG_RETURN_INT32(result);
}
Datum
int2fac(PG_FUNCTION_ARGS)
{
int16 arg1 = PG_GETARG_INT16(0);
int32 result;
if (arg1 == 0)
result = 1;
else if (arg1 < 0)
result = 0;
else
for (result = 1; arg1 > 0; --arg1)
result *= arg1;
PG_RETURN_INT32(result);
}
/* int[24]abs()
* Absolute value