test_grammar.pl

my $CRLF = "\r\n";

my grammar HTTP-message {
    token TOP {
        :my $*transfer-encoding;
        [
        | <!http-version> <request>
        | <?http-version> <response>
        ]
    }

    token request {
        <request-line>
        [ <message-header> $CRLF ]*
        $CRLF
        <message-body>
    }

    token response {
        <response-line>
        [ <message-header> $CRLF ]*
        $CRLF
        <message-body>
    }

    token request-line {
        <method> ' ' $<request-uri>=[ .+? ] ' ' <http-version> $CRLF
    }

    token response-line {
        <http-version> ' ' $<status-code>=[ \d ** 3 ] ' ' $<reason-phrase>=[ \V+ ] $CRLF
    }

    token http-version {
        | 'HTTP/1.0'
        | 'HTTP/1.1'
    }

    token message-header {
        $<field-name>=[ <-[:]>+ ] ':' <field-value>
        {
            if $<field-name>.Str.lc eq 'transfer-encoding' {
                $*transfer-encoding = $<field-value>.trim;
            }
        }
    }

    token field-value {
        [ <!before \h> $<field-content>=[ <-[\r\n]>+ ] | \h+ ]*
    }

    token method {
        OPTIONS | GET | HEAD | POST | PUT | DELETE | TRACE | CONNECT | $<extension-method>=[ \w+ ]
    }

    token message-body {
        .*
    }
}

my $msg =
    "HTTP/1.1 200 OK\r\n"
  ~ "Server: Apache/2.2.3 (CentOS)\r\n"
  ~ "Last-Modified: Sat, 31 May 2014 16:39:02 GMT\r\n"
  ~ "ETag: \"16d3e2-20416-4fab4ccb03580\"\r\n"
  ~ "Vary: Accept-Encoding\r\n"
  ~ "Content-Type: text/plain; charset=UTF-8\r\n"
  ~ "Date: Mon, 02 Jun 2014 17:07:52 GMT\r\n"
  ~ "X-Varnish: 1992382947 1992382859\r\n"
  ~ "Age: 40\r\n"
  ~ "Via: 1.1 varnish\r\n"
  ~ "Connection: close\r\n"
  ~ "X-Cache: HIT\r\n"
  ~ "X-Cache-Hits: 2\r\n"
  ~ "\r\n"
  ~ "008000\r\n"
  ~ "# Last updated Sat May 31 16:39:01 2014 (UTC)\n"
  ~ "# \n"
  ~ "# Explanation of the syntax:\n";

say HTTP-message.parse($msg);
#~ say HTTP-message.parse("Server: Apache/2.2.3 (CentOS)\r\n", :rule<message-header>);
#~ say HTTP-message.parse($msg, :rule<response>);
#~ say HTTP-message.parse("HTTP/1.1 200 OK\r\n", :rule<response-line>);
#~ say HTTP-message.parse("008000\r\n# Last updated Sat May 31 16:39:01 2014 (UTC)\n# \n# Explanation of the syntax:\n", :rule<message-body>);