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=head1 TITLE
rindex and index should return undef on failure
=head1 VERSION
Maintainer: Nathan Torkington <[EMAIL PROTECTED]>
Date: Sep 12 2000
Mailing List: [EMAIL PROTECTED]
Number: 213
Version: 1
Status: Developing
=head1 ABSTRACT
index() and rindex() should return C<undef> if their
second argument is not a substring of their first
argument.
=head1 DESCRIPTION
In perl5, index() and rindex() return -1 if the
substring isn't found. This seems out of step with
the rest of Perl's functions, which return C<undef>
on error. I propose changing index() and rindex()
to return C<undef> if the substring isn't found.
This would also cause warnings to be issued when
programmers use the results of index() or rindex()
assuming the substring was found.
This suggestion doesn't rely on RFC 53, "Built-ins: Merge and
generalize C<index> and C<rindex>", and works regardless
of whether 53 is accepted or not.
=head1 IMPLEMENTATION
The perl526 translator could turn index($a,$b) calls into
do { my $tmp = index($a,$b); defined($tmp) ? $tmp : -1 }
=head1 REFERENCES
RFC 53: Built-ins: Merge and generalize C<index> and C<rindex>
perlfunc manpage for information on index() and rindex()
