rapidjson/doc/features.md

RapidJSON Features

General

• Cross-platform
• Compiler: tested Visual Studio, gcc, clang
• Architecture: x86, x64, ARM
• Operating systems: Windows, Mac OS X, Linux, iOS, Android
• Easy installation
• Header files only library. Just copy the headers to your project.
• Self-contained, minimal dependence
• No STL, BOOST, etc.
• Only included <cstdio>, <cstdlib>, <cstring>, <inttypes.h>, <new>, <stdint.h>.
• High performance
• Use template and inline functions to reduce function call overheads.
• Optional SSE2/SSE4.1 support.

Standard compliance

• RapidJSON should be fully RFC4627/ECMA-404 compliance.
• Support unicode surrogate.
• Support null character ("\u0000") ** For example, ["Hello\u0000World"] can be parsed and handled gracefully.

API style

• SAX (Simple API for XML) style API
• Similar to SAX, RapidJSON provides a event sequential access parser API (GenericReader). It also provides a generator API (GenericWriter) which consumes the same set of events.
• DOM (Document Object Model) style API
• Similar to DOM for HTML/XML, RapidJSON can parse JSON into a DOM representation (GenericDocument), for easy manipulation, and finally stringify back to JSON if needed.
• The DOM style API (GenericDocument) is actually implemented with SAX style API (GenericReader). SAX is faster but sometimes DOM is easier. Users can pick their choices according to scenarios.

Unicode

• Support UTF-8, UTF-16, UTF-32 encodings, including little endian and big endian.
• These encodings are used in input/output streams and in-memory representation.
• Support transcoding between encodings internally.
• For example, you can read a UTF-8 file and let RapidJSON transcode the JSON strings into UTF-16 in the DOM.
• Support encoding validation internally.
• For example, you can read a UTF-8 file, and let RapidJSON check whether all JSON strings are valid UTF-8 byte sequence.
• Support custom encodings.

Stream

• Support GenericStringBuffer for storing the output JSON as string.
• Support FileReadStream/FileWriteStream for input/output FILE object.
• Support custom streams.

JSON formatting

• Support PrettyWriter for adding newlines and indentations.

Memory

• Minimize memory overheads for DOM.
• Each JSON value occupies exactly 16/20 bytes for most 32/64-bit machines (excluding text string).
• Support fast default allocator.
• A stack-based allocator (allocate sequentially, prohibit to free individual allocations, suitable for parsing).
• User can provide a pre-allocated buffer. (Possible to parse a number of JSONs without any CRT allocation)
• Standard CRT(C-runtime) allocator.
• Support custom allocators.