=over

=item redo LABEL
X<redo>

=item redo EXPR

=item redo

The L<C<redo>|/redo LABEL> command restarts the loop block without
evaluating the conditional again.  The L<C<continue>|/continue BLOCK>
block, if any, is not executed.  If
the LABEL is omitted, the command refers to the innermost enclosing
loop.  The C<redo EXPR> form, available starting in Perl 5.18.0, allows a
label name to be computed at run time, and is otherwise identical to C<redo
LABEL>.  Programs that want to lie to themselves about what was just input
normally use this command:

    # a simpleminded Pascal comment stripper
    # (warning: assumes no { or } in strings)
    LINE: while (<STDIN>) {
        while (s|({.*}.*){.*}|$1 |) {}
        s|{.*}| |;
        if (s|{.*| |) {
            my $front = $_;
            while (<STDIN>) {
                if (/}/) {  # end of comment?
                    s|^|$front\{|;
                    redo LINE;
                }
            }
        }
        print;
    }

L<C<redo>|/redo LABEL> cannot be used to retry a block that returns a
value such as C<eval {}>, C<sub {}>, or C<do {}>, and should not be used
to exit a L<C<grep>|/grep BLOCK LIST> or L<C<map>|/map BLOCK LIST>
operation.

Note that a block by itself is semantically identical to a loop
that executes once.  Thus L<C<redo>|/redo LABEL> inside such a block
will effectively turn it into a looping construct.

See also L<C<continue>|/continue BLOCK> for an illustration of how
L<C<last>|/last LABEL>, L<C<next>|/next LABEL>, and
L<C<redo>|/redo LABEL> work.

Unlike most named operators, this has the same precedence as assignment.
It is also exempt from the looks-like-a-function rule, so
C<redo ("foo")."bar"> will cause "bar" to be part of the argument to
L<C<redo>|/redo LABEL>.

=back