Files
nushell/crates/nu-json
Bahex 5478ec44bb to <format>: preserve round float numbers' type (#16016)
- fixes #16011

# Description
`Display` implementation for `f64` omits the decimal part for round
numbers, and by using it we did the same.
This affected:
- conversions to delimited formats: `csv`, `tsv`
- textual formats: `html`, `md`, `text`
- pretty printed `json` (`--raw` was unaffected)
- how single float values are displayed in the REPL

> [!TIP]
> This PR fixes our existing json pretty printing implementation.
> We can likely switch to using serde_json's impl using its
PrettyFormatter which allows arbitrary indent strings.

# User-Facing Changes
- Round trips through `csv`, `tsv`, and `json` preserve the type of
round floats.
- It's always clear whether a number is an integer or a float in the
REPL
  ```nushell
  4 / 2
  # => 2  # before: is this an int or a float?

  4 / 2
  # => 2.0  # after: clearly a float
  ``` 

# Tests + Formatting
Adjusted tests for the new behavior.

- 🟢 toolkit fmt
- 🟢 toolkit clippy
- 🟢 toolkit test
- 🟢 toolkit test stdlib

# After Submitting
N/A

---------

Co-authored-by: Bahex <17417311+Bahex@users.noreply.github.com>
2025-06-26 15:15:19 -05:00
..
2024-03-08 15:29:20 +08:00

nu-json

crate

a fork of serde_hjson.

The changes made to this crate are kept in CHANGELOG.

The Rust implementation of Hjson is based on the Serde JSON Serialization Library.

This crate is a Rust library for parsing and generating Human JSON Hjson. It is built upon Serde, a high performance generic serialization framework.

Install

This crate works with Cargo and can be found on crates.io with a Cargo.toml like:

[dependencies]
serde = "1"
nu-json = "0.76"

From the Commandline

Add with:

 cargo add serde
 cargo add nu-json

Usage

extern crate serde;
extern crate nu_json;

use nu_json::{Map,Value};

fn main() {

    // Now let's look at decoding Hjson data

    let sample_text=r#"
    {
        ## specify rate in requests/second
        rate: 1000
        array:
        [
            foo
            bar
        ]
    }"#;

    // Decode and unwrap.
    let mut sample: Map<String, Value> = nu_json::from_str(&sample_text).unwrap();

    // scope to control lifetime of borrow
    {
        // Extract the rate
        let rate = sample.get("rate").unwrap().as_f64().unwrap();
        println!("rate: {}", rate);

        // Extract the array
        let array : &mut Vec<Value> = sample.get_mut("array").unwrap().as_array_mut().unwrap();
        println!("first: {}", array.first().unwrap());

        // Add a value
        array.push(Value::String("baz".to_string()));
    }

    // Encode to Hjson
    let sample2 = nu_json::to_string(&sample).unwrap();
    println!("Hjson:\n{}", sample2);
}

DOCS

At the moment, the documentation on serde_hjson / serde_json is also relevant for nu-json.