FRXML : Fast/Robust XML parser

FRXML is DOM-based light-weight & robust XML parser, written in C++17 - with a goal that is to archive O(n) level of memory occupancy, regardless of how deep the depth of the xml document is

Benchmark

• lower is better

Features

• zero-copy/single-pass parsing
• UTF-8 supported (without BOM)
• limited XML 1.0

Limitation

• No <! ... > things such as <!DOCTYPE ... or <!ENTITY ... etc...
• No entity(<, &#x20) encoder/decoder (to achieve zero-copy)

Currently, FRXML doesn't support XML 1.0 specification yet. Below is implemented XML format with EBNF format:

document ::= prolog misc* element misc*

prolog ::= pcinstr? /* XML declaration is subset of pcinstr */

name ::= NAME_STARTCHAR NAME_CHAR*

node ::= element | misc
misc ::= comment | pcinstr | S

      element ::= norm_element | empty_element
 norm_element ::= '<' name (S attr)* S? '>' content '</' name '>'
empty_element ::= '<' name (S attr)* S? '/>'
      comment ::= '<!--' '<!--' ((CHAR - '-') | ('-' (CHAR - '-')))* '-->'
      pcinstr ::= '<?' name (S (CHAR* - (CHAR* '?>' CHAR*)))? '?>'
      
content ::= node (S? content)?

Usage

Parsing

#include <iostream>
#include <frxml.h>

int main()
{
    std::string xml = R"(
<?xml version="1.0" encoding="UTF-8"?>
<?ユニコードは 好きですか??>
<!-- HELLO! -->
<xml0>
    <유니코드 attr="안녕하세요" attr0="1"><xml3 />
<!-- HELLO! -->
    </유니코드>
    <?ユニコードは 好きですか??>
    <xml2 attr="c"/>
</xml0>
<!-- HELLO! -->
)";
    frxml::doc doc{ xml };
    if (!doc)
    {
        std::cout << std::to_string(error.exception()) << '\n';
    }
}