filter_del

Remove the calling filter from the active chain. Subsequent reads bypass it and hit the next filter down (or the source file).

Synopsis

filter_del();

What you get back

Nothing useful — filter_del is a statement, not an expression.

It does not stop the current filter invocation: the caller finishes its current call and returns a status to the compiler normally. Starting with the next read, the compiler skips this filter and reads from whatever sat below it in the chain.

Examples

Disable the filter as soon as a sentinel line is seen, so the compiler processes the rest of the file untouched:

sub filter {
    my $status = filter_read();
    if ($status > 0 && /^__END_FILTER__$/) {
        filter_del();
        $_ = '';     # drop the sentinel line itself
    }
    $status;
}

Edge cases

• Calling filter_del when no filter is active is a no-op.

• filter_del marks the filter inactive but does not free its per-filter state; the tokenizer releases that state when it tears down the parser at end of compilation.

Differences from upstream

Fully compatible with upstream Filter::Util::Call 1.65.

See also

• filter_add — installs the filter that filter_del later removes.

• filter_read — normally called right before filter_del in the sentinel branch.