Something that has long bothered me in C and Perl is the return from
index. -1 is such a non-answer to me.
In Perl 6, I was wondering if it would make sense for functions that
return a count or index to set the truth property as well. For example,
allowing:
if index($subject,"**SPAM**") {
warn "SpamAssassin doesn't like you :)";
}
There are a lot of functions that do what index does or which return a
success count for list of actions (e.g. unlink or chmod). Should all of
these break with Perl 5's notion of boolean success and use Perl 6's
model?
Here's a sample of some of those:
# Slow matching for example purposes
sub index($string, $substr, int $pos //= 0) {
my int $subl = length($substr);
my int $strl = length($string);
for(int $i = $pos; $i+$subl <= $strl; $i++) {
return $i but true if substr($string,$i,$subl) eq $substr;
}
return -1 but false;
}
sub all_or_false(&code, @items) {
my $ok = 0;
for @items -> $_ {
$ok++ if code($_);
}
if $ok == @items {
return $ok but true;
} else {
return $ok but false;
}
}
sub chmod(int $mode, *@paths){
return all_or_false {syschmod($_,$mode)} @paths;
}
# ... also do chown, utime, kill, utime and unlink this way
--
Aaron Sherman <[EMAIL PROTECTED]>
http://www.ajs.com/~ajs
