Comments on: Code idiom: using logical ^ to change your mind

By: Will Sargent

Will Sargent — Fri, 12 Sep 2003 17:37:02 +0000

Just plain evil.

By: Anonymous Coward

Anonymous Coward — Fri, 08 Aug 2003 21:50:43 +0000

too clever by half.
..at least.

By: Kevin Greer

Kevin Greer — Thu, 05 Jun 2003 13:49:58 +0000

Or just:
return result != invert;

By: Kevin Greer

Kevin Greer — Thu, 05 Jun 2003 13:48:46 +0000

You could also do:
return result == ! invert;

By: Oliver Burn

Oliver Burn — Mon, 31 Mar 2003 09:49:06 +0000

While I agree with you Brendan, I would redo your example as:

final boolean result = evaluateCondition(); return (invert) ? !result : result;

I find this approach improves code coverage and is easier to read. >:)

By: Brendan Humphreys

Brendan Humphreys — Mon, 31 Mar 2003 03:41:39 +0000

Matt wrote: This idiom is a cool little trick, but I've seen coders scratching their head trying to work out what it does; so a detailed explanation is in order.

I think the fact that coders are scratching their heads makes this more of a "trick" and less of an "idiom". That you leave coders puzzled is enough of a reason not to use it, since it doesn't really buy you much, and the readability of the code is reduced.

For me, I'd prefer to see it spelt out: boolean result = evaluateCondition();

if (invert) { result = !result; } return result;

Sure it's a bit more typing, but it doesn't require the audience to have a knowledge of an arguably obscure language feature. When running the latter chunk thru my wetware language parser, it reads quickly and elegantly.

By: Oliver Burn

Oliver Burn — Thu, 27 Mar 2003 09:34:03 +0000

You made me :? quite hard with this one, but I am now

By: Alan Green

Alan Green — Wed, 26 Mar 2003 19:56:18 +0000

I’ve recently saw a pair of conditional tags and implemented with an abstract base class that has the method:
protected abstract boolean isNullAGoodThing()
Each tag is implemented with a very short subclass, one implementing this method as "return true", and the other "return false". I’ll have a look at that code again and see if I could replace it with a single class using ‘^’.

Alan

PS: Your smileys are just too cute