> not ternary, just "binary",
yes it's binary.
> $var1 ?= die "ERROR: \$var1 already set." : $var2;
Thanks for demonstrating your use case, it's even stranger than I expected! ;-)
die will not return a value - actually it won't return at all.
> Maybe you'll see more elegant way how to do such thing.
Yes with a properly named custom-function operating on an alias.
something like
sub init {
die "ERROR: \$var already set." if defined $_[0];
$_[0] = $_[1];
}
init $var1 => 'value1'; # pretty elegant, right?
init $var2 => 'value2';
init $var3 => 'value3';
Please note the defined° , cause else wise you'd miss false values like 0 or "". (which renders your requirement for a new operator a bit useless)
UPDATE:
- if you need the proper $var name use PadWalker
- use Carp to report from the perspective of the caller
°) a shorter way would have been $_[0] // die 'ERROR: ...';
Off by one, it's the inverted case :)
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