1 unstable release

0.1.0 Nov 26, 2023

#2643 in Parser implementations

MIT license

32KB
673 lines

fson

FSON (Flexible Serialized Object Notation) is an extension for JSON that is used primarily for configuration. The user can quickly configure the configuration using references or a template strings.

Features

Comments and new values

/* Multiline comment */ [null, NaN, Infinity, -Infinity, 0x1ABC /*Hexadecimal*/] // Single comment

Identifiers

  • You can use identifiers without quotes and with single quotes:
{
    "double quotes": null,
    'single quotes': null,
    withoutQuotes: null
}

References

  • A reference is an object that can be anywhere (it can be either a pair of an object or it can be in an array) that can be referenced using it's identifier or path. For example:
{
  something: {
      key: #{ #id: "identifier"; #value: "value"; }
  }
}
  • The reference in the example above can be referenced in two ways:
    • Using it's identifier: #identifier or #"identifier"
    • Using it's path: #/something/identifier or #/"something"/"identifier"

Template strings

  • Template strings are strings enclosed in backticks. They allow you to embed other values (including references) in them using ${value}. For example:
    {
      x: 5,
      something: `x is ${x}`
    }
    

Other

  • Objects and arrays can have a trailing comma: { x: { y: [], }, }
  • Numbers can start with a plus: +1.5
  • Strings can be multiline:
"hello
world"
  • Whitespaces don't matter

Examples

See all examples in Examples directory.
How to run example: cargo run --example EXAMPLE_NAME

Compiling to WebAssembly

FSON is already ready for compilation to WebAssembly and already has the necessary functions. js-sys and wasm-bindgen libraries and functions are used only when compiling to WebAssembly.
Use these commands to compile to wasm:

# Install wasm-pack
cargo install wasm-pack

# Compile to wasm
wasm-pack build --target web
JavaScript example
import init, { parse, stringify } from "./jsonparser.js";
init().then(() => {
  console.log(stringify({
    // Creating reference
    x: {
      "#id": "test",
      "#value": "value",
    },

    // Using reference
    y: [
      // Identifier
      { "#reference_id": "test" },

      // Path
      { "#reference_path": ["x"] },

      // Template string
      {
        "@template_string": [
          "test is ",
          { "#reference_id": "test" }, /* Reference */
          "; 2 + 2 = ",
          4, /* Normal value */
        ],
      },
    ],
  }));
});

License

MIT

Dependencies

~2.1–3MB
~59K SLoC