[PHP4BETA] Re: IS_* macros

At 00:02 11/05/99 , Andrey Zmievski wrote:

Is there any reason the IS_* macros were defined to have sequential values instead of multiples of 2 like php3?

#define IS_LONG      1

#define IS_DOUBLE 2 #define IS_STRING 3 #define IS_ARRAY 4 #define IS_OBJECT 5

#define IS_BC     6 /* for parser internal use only */
#define IS_BOOL      7

#define IS_RESOURCE 8 #define IS_CONSTANT 9 #define IS_METHOD 10 /* for overloaded function calls */ and php3 had #define IS_LONG 0x1 #define IS_DOUBLE 0x2 #define IS_STRING 0x4 #define IS_ARRAY 0x8 #define IS_USER_FUNCTION 0x10 #define IS_INTERNAL_FUNCTION 0x20 #define IS_CLASS 0x40 #define IS_OBJECT 0x80 It was so much more convenient to check if the variable was not array or object by doing: if (!(value->type & (IS_ARRAY|IS_OBJECT)) and with current macros you can't do that now. Can that be changed?

It's for memory performance reasons. There was no real reason to use bit fields for the variable type. With PHP 4.0, there's almost never a reason to do that (especially your particular check for seeing whether a variable is either an array or object, now that the low level representation of objects and arrays is entirely different). Since we now have over 8 types, and since we can only allow a single byte for the size of the variable type, using bit fields is no longer an option. Zeev -- Zeev Suraski <zeev@zend.com> http://www.zend.com/ For a PGP public key, finger bourbon@netvision.net.il -- PHP 4 Beta