#value #pointers #i32 #f64 #u32 #boolean #nan-tagged

nanoval

A nan-tagged value for representing f64, i32, u32, booleans, null and arbitrary pointers

5 unstable releases

0.3.1 Apr 30, 2024
0.3.0 Apr 30, 2024
0.2.1 Apr 30, 2024
0.2.0 Apr 30, 2024
0.1.0 Apr 29, 2024

#879 in Rust patterns

Download history 334/week @ 2024-04-26 38/week @ 2024-05-03

372 downloads per month

MIT license

16KB
329 lines

nanoval - A NaN-tagged value

This library provides an implementation of a NaN-tagged value supporting f64, bool, i32, u32, null-values and a subset of pointers. Each value is only 8 bytes in size and uses the large space of NaN values to store additional information inside a single 64 bit double precision floating point value.

This implementation is heavily inspired by the Wren programming language, although it does differ in some aspects.

If you find a bug or have ideas for improvements, please open an issue or a pull request.

I hope you find this library useful!

Usage

The Value type can be constructed from f64, bool, i32, u32, i64, () and pointers to arbitrary T:

use nanoval::Value;

fn creation() {
    let double = Value::from(3.14);
    let integer = Value::from(42);
    let boolean = Value::from(true);
    let null = Value::from(());
    let pointee = 42;
    let pointer = Value::try_from(&pointee as *const i32).unwrap();
}

The constructed value can be converted back to the original type:

fn getters() {
    assert_eq!(double.as_f64(), Some(3.14));
    assert_eq!(integer.as_int(), Some(42));
    assert_eq!(boolean.as_bool(), Some(true));
    assert!(null.is_null());
    assert_eq!(pointer.as_pointer::<i32>(), Some(&pointee as *const i32));
}

No runtime deps