Support HTTP protocol parse

[4ra1n]

Describe the solution you'd like
I need to use RSyntaxTextArea to parse and process HTTP packets.

Are there any workarounds?
Not support now.

Additional context

For example, the Github editor supports highlighting HTTP

GET /test.jsp HTTP/1.1
User-Agent: test
Accept-Encoding: gzip, deflate, br
Cache-Control: no-cache
Pragma: no-cache
Host: 127.0.0.1:8080
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive

[4ra1n]

[METHOD] [PATH] [VERSION]
[HEADER-KEY]: [HEADER-VALUE]
...
[BODY]

[4ra1n]

/*
 * HTTPTokenMaker.flex - Token generator for HTTP messages.
 *
 * This library is distributed under a modified BSD license. See the included
 * LICENSE file for details.
 */

package org.fife.ui.rsyntaxtextarea.modes;

import java.io.*;
import javax.swing.text.Segment;

import org.fife.ui.rsyntaxtextarea.*;

/**
 * Scanner for HTTP messages.
 *
 * This file defines tokens for various parts of HTTP messages including
 * methods, headers, status codes, and message bodies.
 *
 * @author Your Name
 * @version 1.0
 */
%%

%public
%class HTTPTokenMaker
%extends AbstractJFlexTokenMaker
%unicode
%ignorecase
%type org.fife.ui.rsyntaxtextarea.Token
%{

    /**
     * Constructor. This must be here because JFlex does not generate a
     * no-parameter constructor.
     */
    public HTTPTokenMaker() {
        super();
    }

    /**
     * Adds a token to the linked list of tokens.
     *
     * @param tokenType The token's type.
     */
    private void addToken(int tokenType) {
        addToken(zzStartRead, zzMarkedPos - 1, tokenType);
    }

%}

%%

// HTTP Methods
GET|POST|PUT|DELETE|HEAD|OPTIONS|PATCH|TRACE {
    addToken(Token.RESERVED_WORD);
    yybegin(YYINITIAL);
}

// HTTP Versions
HTTP\\/1\\.0|HTTP\\/1\\.1|HTTP\\/2 {
    addToken(Token.LITERAL_STRING_DOUBLE_QUOTE);
    yybegin(YYINITIAL);
}

// Status Codes
[1-5][0-9]{2} {
    addToken(Token.LITERAL_NUMBER_DECIMAL_INT);
    yybegin(YYINITIAL);
}

// Headers
[a-zA-Z\\-]+: {
    addToken(Token.DATA_TYPE);
    yybegin(YYINITIAL);
}

// String Values in Headers
\"([^\"\\\\]|\\\\.)*\" {
    addToken(Token.LITERAL_STRING_DOUBLE_QUOTE);
    yybegin(YYINITIAL);
}

// Message Body
[^\\n\\r]+ {
    addToken(Token.IDENTIFIER);
    yybegin(YYINITIAL);
}

// Whitespace
[ \\t\\n\\r]+ {
    addToken(Token.WHITESPACE);
    yybegin(YYINITIAL);
}

// Comments or Unexpected Syntax
. {
    addToken(Token.ERROR_IDENTIFIER);
    yybegin(YYINITIAL);
}