Re: [rules-dev] Drools syntax diagrams - redrawn
On 23 September 2010 09:31, Bruno Unna <bruno.unna(a)gmail.com> wrote:
FWIW: in Perl, there are both operators as well (|| and
'or'). However,
they are *not* exactly the same. Although they can be used in any context to
render a boolean expression, their priority makes the difference. Taken from
official documentation (http://bit.ly/dgw4GT):
Low precedence "and", "or", "xor" were introduced to
permit "Perl poetry",
or, more seriously, to
permit control flow using a logical expression, especially after function
calls without parentheses.
see Naples or die; # same as: see(Napes) || die(); but not: see(Naples
|| die() );
No way this makes any sense in Drools.
-W
Binary "or" returns the logical disjunction of the two surrounding
expressions. It's equivalent to || except for the very low
precedence. This
makes it useful for control flow.
Nonetheless, it must be taken into account that the distinction makes sense
for a Perl programmer. For a rules-writing guy (or girl) perhaps the
distinction is extremely obscure.
Regards.
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