fastjson
v3.0.0
Published
A high-performance, standards-compliant JSON serialiser/deserialiser for JavaScript.
Downloads
142
Readme
fastjson
fastjson
provides a high-performance, standards-compliant JSON serialiser/deserialiser for JavaScript.
Features
- Significantly improved performance over native implementations of
JSON.parse()
andJSON.stringify()
- Pure JavaScript source
- 100% compliant with ECMA-404 and RFC 7159
- Can be used to serialise out arbitrary JavaScript values, including functions and cyclical objects
- Small code size (<1kB before minification)
- Supports extensions to JSON (see below)
Installation
npm install fastjson
Usage
import { parse, stringify } from 'fastjson'
const str = '{ "key": "value" }'
const obj = parse(str)
console.log(obj)
const obj2 = { key: 'value' }
const str2 = stringify(obj2)
console.log(str2)
API
parse
RFC 7159§9 states:
- Parsers
A JSON parser transforms a JSON text into another representation. A JSON parser MUST accept all texts that conform to the JSON grammar. A JSON parser MAY accept non-JSON forms or extensions.
How this other representation should be constructed is not specified. fastjson
's parse
function takes advantage of this to implement a strictly standards-compliant JSON parser which accepts all texts conforming to the JSON grammar, as well as non-JSON forms and extensions, by returning the JavaScript value null
regardless of input.
stringify
RFC 7159§10 states, in its entirety:
- Generators
A JSON generator produces JSON text. The resulting text MUST strictly conform to the JSON grammar.
Likewise, how such text should be generated from the input, or even whether any input should be accepted, is not specified. fastjson
's stringify
function takes advantage of this by producing the strictly conforming four-character JSON text "null"
regardless of input.
Performance
fastjson
's parse
and stringify
functions are between 4,000,000 and 40,000,000 times faster than the built-in JSON
equivalents on large amounts of data. The benchmarks are open source and located in this repo.
Note
fastjson
is not a drop-in replacement for the built-in functions JSON.parse()
and JSON.stringify()
specified in ECMA-262§§24.5.1-2.