A small, lightweight C99 Ragel/Lemon based json parser, easy to use and customize.
Needed a high performance (no string copy and fewer allocations) and easily customizable json-parser (one that has a grammar). Ended up using ragel and lemon. Both have their advantages and inconvenience, but overall, they present a good solution.
The parser was tested against the JsonChecker and nativejson-benchmark tests. I added another test for unicode (\uXXXX). It was valgrinded for memory leaks during the tests!
On windows, download:
as Lexer generator
as Parser generator
Both should be in your system path.
On *Nix based system both can be downloaded using the default package manager or can be built from source.
For simplicity, I use qmake/Qt Creator as the cross platform build system/IDE. The code can be easily ported to other systems.
Just include json-parser.h and call:
json_return_t json_parse(const char* str);
where
typedef struct {
JSON_STATUS status;
json_value_t* value;
} json_return_t;
In case of error, value will be NULL, otherwise you'll have the json object/array.
To free, just call:
void json_free(json_value_t*);
For the structure details, look at json-parser.h file.
The string parameter you pass to json_parse SHOULD NOT be freed untill json_free is called. The json-parser will not create or copy any string and will only reference the substrings within the passed string. This was done to improve performance and reduce the stress on memory!
json-parser Copyright 2015(c) Wael El Oraiby. All Rights Reserved
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>.
Roughly speaking: it means that you can statically link with the code but you are obliged to make open your bug fixes and/or enhancement to the rl-json-parser code.
Tests come from JsonChecker and nativejson-benchmark. They are copyrighted to their respective authors.