use Parse::RecDescent;

#$RD_TRACE=1;

my $parser = Parse::RecDescent->new(<<'EOGRAMMAR');

    file:         <skip:''> item(s)

    item:         directive
        |         text

    directive:     '<%' <skip:'\\s*'> command arg(s?) m|/?%>|
                { $return = bless \%item, 'directive' }

    command:     m|/?[a-z]\w*|i

    arg:        argname '=' string
                { $return = \%item }
       |        string
                { $return = \%item }
       |        data
                { $return = \%item }

    argname:    /[a-z]\w*/i

    string:        '"' /[^\\"]*(\\.[^\\"]*)*/ '"'
                { $return = $item[2] }

    data:        m|((?!/?%>)\S)+|


    text:         /((?!<%).)+/s
                { $return = bless \$item[1], 'text' }

EOGRAMMAR

my $data = join '', <DATA>;

my $info = $parser->file($data);

use Data::Dumper;

print Data::Dumper->Dump($info);

__DATA__

<% If expr %>
the if worked
<% Else %>
it didn't work
<% /If %>
   >
<% Include file="foo.txt" /%>
   >
<% Run Function="myFunc" Attr="x" ...%>
<% Arg Name="row" %>
<TR><TD>Name</TD><TD>{name}</TD></TR>
<% /Arg %>
<% /Run %>