https://github.com/storycraft/fn-map

Abstraction around HashMap. Uses closure to compute and store value.
https://github.com/storycraft/fn-map

hashmap rust type-store

Last synced: 2 months ago
JSON representation

Abstraction around HashMap. Uses closure to compute and store value.

• Host: GitHub
• URL: https://github.com/storycraft/fn-map
• Owner: storycraft
• Created: 2023-06-29T07:48:50.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2024-06-15T05:10:02.000Z (6 months ago)
• Last Synced: 2024-10-06T21:37:01.902Z (3 months ago)
• Topics: hashmap, rust, type-store
• Language: Rust
• Homepage:
• Size: 64.5 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# FnMap

FnMap is a abstraction around the HashMap, like TypeMap. But uses closure's type(each closure's type is *unique* in Rust) as key and stores produced *value*. Allowing to be used like effective low cost dependency injection container.

## Usage

```rust

use fn_map::FnMap;

let map = FnMap::new();

fn one() -> i32 {

    println!("one computed");

    1

}

// get or compute(and insert) value using given closure. The closure depends on value of `one` function to compute its output.

let a = *map.get(|| map.get(one) + 1);

dbg!(a);

// b is *not* a because each closure's type is unique

let b = *map.get(|| map.get(one) + 1);

dbg!(b);

// get or compute(and insert) value using give function. But will not compute since it is computed already when producing a.

let c = *map.get(one);

dbg!(c);

```

will output

```bash

one computed

a = 2

b = 2

c = 1

```

# License

MIT