in reply to A set of new operators. In keeping with the design of Perl?

Perhaps the best example of this is $var ||= 100; which is shorthand for $var = 100 unless $var; or even if( not $var ) { $var = 100; }

Actually, it's a shorthand for $var = $var || 100;, just like how $var += 4; is a shorthand for $var = $var + 4;

?<:= ?>:= ?<=:= ?>=:= ?lt:= ?gt:= ?ge:= ?le:=

I don't like them. Too hard to remember and too ugly.

maybe in perl 6?

http://dev.perl.org/perl6/list-summaries/p6summary.2003-02-09.pod.html#shortcut%20=

Finally, is it possible to invent new operators using overload? Or would you have to resort to source filters to implement this outside of the core?

No; yes.

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }

Replies are listed 'Best First'.
Re: Re: A set of new operators. In keeping with the design of Perl?
by BrowserUk (Patriarch) on May 19, 2003 at 07:54 UTC

    Thanks for the link juerd, I hadn't seen that discussion. However, I think that my idea is quite different to that proposal which suggested a short-hand for the trinary operator involving 3 operands.

    eg. $var ??= $x : $y;

    The operators I am seeking only involve 2 operands.

    Too hard to remember ...

    This: $var = $var op $expr ? $var : $expr;

    becomes this: $var ?op:= $expr;

    Is that hard to remember?

    ...and too ugly.

    Agreed, they ain't beauiful. I was trying to retain the notions of the ternary and the operators and the assignment, but as they are no longer ternary, maybe the ? or the final = could be dropped: 

    # Instead of these               these or               these?
$lvalue  ?<:= $rvalue;   $lvalue  <:= $rvalue;   $lvalue ?<:  $rvalue;
+     
$lvalue  ?>:= $rvalue;   $lvalue <=:= $rvalue;   $lvalue ?>:  $rvalue;
+     
$lvalue ?<=:= $rvalue;   $lvalue  >:= $rvalue;   $lvalue ?<=: $rvalue;
+     
$lvalue ?>=:= $rvalue;   $lvalue >=:= $rvalue;   $lvalue ?>=: $rvalue;
+     
$lvalue ?lt:= $rvalue;   $lvalue lt:= $rvalue;   $lvalue ?lt: $rvalue;
+     
$lvalue ?gt:= $rvalue;   $lvalue le:= $rvalue;   $lvalue ?gt: $rvalue;
+     
$lvalue ?ge:= $rvalue;   $lvalue gt:= $rvalue;   $lvalue ?ge: $rvalue;
+     
$lvalue ?le:= $rvalue;   $lvalue ge:= $rvalue;   $lvalue ?le: $rvalue;

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