rule code_begin ($type) {
    <{
        {
            asp => '<%',
            php => '<?',
            plp => '<:' 
        }.{$type} // fail "Unknown type: $type"
    }>
}

rule code_end ($type) {
    <{
        {
            asp => '%>',
            php => '?>',
            plp => ':>' 
        }.{$type} // fail "Unknown type: $type"
    }>
}

rule code_block ($type) {
    <code_begin $type> (.*?) <code_end $type>
}

rule code_document ($type) {
    [
        # First, match any number of subsequent code blocks.
        [
            { $?line := .pos.line }
            <code_block $type> ::
            { push @?blocks, [ $?line, code => $?code_block ] } 
        ]*
        
        # If there is now a code_begin, obviously that is an open block.
        # (In PLP, that is valid, but let's assume for now that it's not.)
        [ 
            { $?line := .pos.line }
            <code_begin $type> \n* $?context := (\N<,15>) 
            { fail "Unclosed code block on line $?line, near '$?context'" }
        ]?

        # And then a piece of text.
        # (At least one character, to avoid having empty blocks.)
        [
            { $?line := .pos.line }
            $?html := (.+?) [ <before <code_begin $type>> | $ ] ::
            { push @?blocks, [ $?line, html => $?html ] } 
        ]?
    ]*    
}

my @parsed = ($asp ~~ /<code_document 'asp'>/).{blocks}