Boolean Expressions (was: Re: Comments against TMQL draft 2006-02-22)
Lars Heuer <[email protected]> Sat, 10 Mar 2007 12:03:59 +0100
| Newsgroups | gmane.text.xml.xtm.tmql |
|---|---|
| Organization | Semagia |
| Message-ID | <[email protected]> |
Hi Robert, [...] >> 4.13 Boolean Expressions >> ------------------------ [...] > & symmetric, non-short circuit AND > && does not exist in TMQL > | symmetric, non-short circuit OR > || asymetric, short-circuit OR (can be defined via if-then-else) > This is the same in Java, which got it from C++ which got it from C..... > I would not advise to switch & to short-circuit because this can > dramatically undermine automatic optimization. Ok. IMO the boolean expr. need some more explaining words. Someone might get the impression that you mean with "non short-circuit", that every operant has to be evaluated even if the first operant evaluates to "false" in an ANDed expression. That is not meant (I hope ;)). With not short-circuit you mean, that the processor might evaluate the operants in a boolean expression in any order it likes. But once the proc. gets something that can be interpreted as false it can work with the "false"-value (in an AND expression). Best regards, Lars -- http://www.semagia.com