Thread

1. Changing constant in src/include/miscadmin.h

   Yury Bokhoncovich <byg@center-f1.ru> — 2002-03-20T13:17:40Z

   Hello!
   
   Is it valid to change a constant in src/include/miscadmin.h?
   
   ===========================
   @@ -150,10 +150,10 @@
   
    #define MAXTZLEN               10              /* max TZ name len, not counting tr. null */
   
   -#define USE_POSTGRES_DATES             0
    #define USE_ISO_DATES                  1
    #define USE_SQL_DATES                  2
    #define USE_GERMAN_DATES               3
   +#define USE_POSTGRES_DATES             4
   
    extern int     DateStyle;
    extern bool EuroDates;
   ===========================
   
   This can make easy parsing of date style in parse_datestyle_internal
   function (src/backend/commands/variable.c) in this way:
   
   datestyle=0;
   if () datestyle=USE_xxx
   ...
   if (!datestyle) elog(ERROR
   
   -- 
   WBR, Yury Bokhoncovich, Senior System Administrator, NOC of F1 Group.
   Phone: +7 (3832) 106228, ext.140, E-mail: byg@center-f1.ru.
   Unix is like a wigwam -- no Gates, no Windows, and an Apache inside.
   
   
   
   

2. Re: Changing constant in src/include/miscadmin.h

   Thomas Lockhart <thomas@fourpalms.org> — 2002-03-20T15:10:32Z

   > Is it valid to change a constant in src/include/miscadmin.h?
   > -#define USE_POSTGRES_DATES             0
   > +#define USE_POSTGRES_DATES             4
   
   Yes, the code should still work and afaik these values are not embedded
   anywhere other than in the compiled code so you will stay
   self-consistant.
   
   > This can make easy parsing of date style in parse_datestyle_internal
   > function (src/backend/commands/variable.c) in this way:
   > datestyle=0;
   > if () datestyle=USE_xxx
   > ...
   > if (!datestyle) elog(ERROR
   
   At the moment, one is allowed to call parse_datestyle_internal() only
   setting the "european" vs "noneuropean" flag for month and day
   interpretation. So the code should not have the check mentioned above.
   
   Also, I would suggest using an explicit comparison rather than an
   implicit comparison against zero. Something like
   
   #define DATESTYLE_NOT_SPECIFIED 0
   datestyle = DATESTYLE_NOT_SPECIFIED
   ...
   if (datestyle == DATESTYLE_NOT_SPECIFIED) elog()...
   
   where the #define is in the same place as the USE_xxx definitions. That
   way you aren't relying on someone remembering that they *shouldn't* use
   zero as one of the possible valid values. And that way the
   DATESTYLE_NOT_SPECIFIED does not actually have to be zero.
   
                          - Thomas