Re: stupid Matlab-style short-circuit behavior for | and &

[John W. Eaton]

On  9-Oct-2010, Ben Abbott wrote:

| 
| On Oct 9, 2010, at 5:48 AM, Søren Hauberg wrote:
| 
| > fre, 08 10 2010 kl. 16:36 -0400, skrev John W. Eaton:
| >> On  8-Oct-2010, Jaroslav Hajek wrote:
| >> 
| >> | No, apparently I just didn't realize how stupid this is :) Your first
| >> | solution was probably fine.
| >> 
| >> OK, I checked it in.  You can turn the feature on or off with
| >> 
| >>  do_braindead_shortcircuit_evaluation
| >> 
| >> By default there is a warning at parse time if an & or | expression is
| >> found in the condition of a WHILE of IF statement.  You can disable
| >> the warning with
| >> 
| >>  warning off Octave:possible-matlab-short-circuit-operator
| >> 
| >> If you start Octave with --traditional the feature is enabled and the
| >> warning is disabled.
| > 
| > So, does that mean we do the brain-dead (i.e. Matlab compatible)
| > evaluation by default or is it something you have to manually enable?
| > 
| > Søren
| 
| After starting Octave with no options ...
| 
| octave:1> which do_braindead_shortcircuit_evaluation
| `do_braindead_shortcircuit_evaluation' is a built-in function
| 
| octave:2> do_braindead_shortcircuit_evaluation
| ans = 0
| 
| It is off by default.

Right, and the warning is on by default because I would like to steer
people toward using || and && for logical operations, and also with
the option of turning on the stupid Matlab-compatible feature, we need
to know when it might affect our code.  With the last two changesets I
have checked in, I think I have eliminated all cases in the Octave
sources.

jwe