Dean Brooks wrote: > On Wed, Jan 03, 2007 at 05:06:54PM +0000, Dave Evans wrote: > >> On Wed, Jan 03, 2007 at 08:46:28AM -0800, Marc Perkel wrote: >> >>> A null and a blank string are not the same thing either. Are you going >>> to treat strings that way too? >>> >> Not a fair comparison IMO, because although variables can be null, the result >> of string expansion can (AFAIK) never be null. (e.g. h_Cc may be null, but >> expanding $h_Cc: yields the empty string). Since the operands of string ops >> (e.g. eq) are always acquired by first performing a string expansion, which >> can *only* yield a (possibly empty) string, the operands can never be >> anything >> but strings. Unless I've missed something. >> > > Exim has no concept of nulls in its string expansions, only blank > strings. The word "null" should not be used in this discussion as > nulls do not exist in the constructs being discussed. That is, Exim's > "def:" condition simply tests to see if the variable is equal to an > empty string. > > That being said, empty strings in integer comparisons seem completely > reasonable given that Exim is *already* doing a conversion from string > to integer form in this process. > > By documenting that an empty value is equal to zero, and informing the > user to be aware of this and to depend on it seems completely > reasonable. Especially if it helps avoid breaking otherwise simple > expressions and confusing the heck out of new users. > > -- > Dean Brooks > [EMAIL PROTECTED] > >
If null = "" and if "" = 0 then null = 0. -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
