oh, it might not be relevant in many ways but :



There's one thing I would like perl6 to shine in, is web and open source.
I know it's not the purpose of the language
and that the above articles are placed in a particular
context but I guess this can explain to some extends
why both perl don't have a widespread use in entreprise
and in open source project
(I have looked for them but they are little and some of them
like movable type moves to php at each upgrade)

cdumont wrote:

Patrick R. Michaud wrote:

On Mon, Dec 03, 2007 at 12:20:02PM +0000, Smylers wrote:
cdumont writes:
I don't really think using the column in a ternary means that you
cannot use it else where.

We started off with that, and it was changed specifically because it was
causing a problem; I can't remember exactly what, but it's in this
list's archives somewhere.

Remember that whatever expression you want to use the colon for is going
to be valid between the ? and : parts of the ? ... : operator, and so
you need to avoid the colon being confused for the : which marks the end
of this part of the ? ... : operator.

...and it's not just the colon, but the ? also has the potential to be
confusing here, because there's a prefix:<?> operator that is used to
coerce into boolean context.

Which indirectly gets around to an even stronger reason for using
C<?? !!> over C<? :> -- Perl 6 aims for a consistency in the
use of the ? and ! characters to mean "boolean true" and "boolean
not true".  This is true not only for the operators, but also in
regular expressions and other places.  So, having something like

   $foo =  $cond ?? ...if_true... !! ...if_not_true... ;

achieves several important goals:
 - it frees up the ? and : characters for other purposes
 - it reinforces the convention of ? as "if true" and ! as "if false"
 - it is more visually distinctive, so that the ternary tokens don't
   get lost in the middle of other operands and expressions
 - it simplifies parsing (both compiler and human) and improves
   error reporting

In my case, I've found the switch to ?? !! to be fairly
natural, and that I don't use it often enough to worry about
the extra characters.
OK that explains the logic behind the conclusion. Thank you!
I don't use it that much either but it was for the sake of coherence with other languages
but Mr. Wall got the point in his response!

シリル・デュモン(Cyrille Dumont)
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