Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"

Re^4: A "but" operator.

by Velaki (Chaplain)
on Sep 28, 2004 at 02:37 UTC ( #394442=note: print w/replies, xml ) Need Help??

in reply to Re^3: A "but" operator.
in thread A "but" operator.

Since "A but B" is really a conjunctive inversion, discursively it should be equivalent to "A and not B".

And since "A and not B" is equivalent to "not (if A then B)", or in other words, "not (B if A)", couldn't this be said thusly, to be perly, "B unless A"?

"Perl. There is no substitute."

Replies are listed 'Best First'.
Re^5: A "but" operator.
by dragonchild (Archbishop) on Sep 28, 2004 at 12:34 UTC
    This is where predicate logic doesn't work as well as set theory. "A but B" is actually more akin to "A minus B", where A and B are both sets. Or, in Perl,
    my @A = ( ... ); my @B = ( ... ); my %B = map { $_ => !!1 } @B; # "A but B" grep { !$B{$_} } @A;

    Which is very close to the mixin concept that Perl6 will apply to the term "but".

    Being right, does not endow the right to be rude; politeness costs nothing.
    Being unknowing, is not the same as being stupid.
    Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence.
    Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.

    I shouldn't have to say this, but any code, unless otherwise stated, is untested

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://394442]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others perusing the Monastery: (4)
As of 2016-10-22 02:57 GMT
Find Nodes?
    Voting Booth?
    How many different varieties (color, size, etc) of socks do you have in your sock drawer?

    Results (291 votes). Check out past polls.