With the grammar:

    line: FOO BAR /$/
    FOO: "foo"
    BAR: "bar"
[download]

and the invocation changed line to:

    if (defined (my $ret = $p->line($test))) {
[download]

I get:

no match: 'foo'
no match: 'foo '
match: 'foo bar' -> ''
no match: 'football'
no match: 'fog'
no match: 'barfoo'
no match: 'bar foo'
[download]

Is that not what you expect?