Crate goldilocks_json_fmt

A simple, portable, fast, pretty JSON formatter. No dependencies or unsafe code.

The resulting JSON strikes a balance between ‘too wide’ (i.e. minified, all on one line) and ‘too tall’ (e.g. serde_json’s pretty_print). You give the formatter a line limit (defaults to 100 chars), and it keeps things as wide as possible whilst preserving that limit. Sometimes the limit is impossible to achieve (e.g. you have a string that’s longer than the line limit), in which case the formatter will break the limit by as little as possible.

The throughput of the Goldilocks formatter is about 300MB/s, which should be enough for most situations. It’s about as fast as you can get without cracking out the big guns and using SIMD, which would break both simplicity and portability.

Example:

// Ewww so horrible
let json = r#"{"test/cases/87s-at-back.toml":{"comps":[{"length":32,
    "string":"sHsH","avg_score":-0.45625},{"length":64,"string":"sHWsMH",
    "avg_score":-0.44062495},{"length":96,"string":"WMsWMHsH","avg_score":
    -0.33124998},{"length":96,"string":"WsMHWsMH","avg_score":-0.33124998},
    {"length":96,"string":"sHWMsWMH","avg_score":-0.33124995},{"length":64,
    "string":"WsMHsH","avg_score":-0.284375}]}}"#;

let perfect_json = goldilocks_json_fmt::format(&json).expect("Invalid JSON");

assert_eq!(
    &perfect_json,
    // So perfect!
    r#"{
  "test/cases/87s-at-back.toml": {
    "comps": [
      { "length": 32, "string": "sHsH", "avg_score": -0.45625 },
      { "length": 64, "string": "sHWsMH", "avg_score": -0.44062495 },
      { "length": 96, "string": "WMsWMHsH", "avg_score": -0.33124998 },
      { "length": 96, "string": "WsMHWsMH", "avg_score": -0.33124998 },
      { "length": 96, "string": "sHWMsWMH", "avg_score": -0.33124995 },
      { "length": 64, "string": "WsMHsH", "avg_score": -0.284375 }
    ]
  }
}"#,
);

Structs

Config

Configuration options for JSON formatting with format_with_config.

Enums

Error

The possible ways that JSON parsing could fail

Expected

What was expected in a given position

Item

An item that could be being parsed when an error was generated

Functions

format

Formats the given JSON with default Configuration.

format_with_config

Formats the given JSON with the given Configuration, returning an Error if the JSON wasn’t valid.

format_within_width

Formats the given JSON with the default Configuration but a custom line length limit.

Type Definitions

Result