https://github.com/oppiliappan/cutlass

experimental auto-currying for rust functions
https://github.com/oppiliappan/cutlass

Last synced: 3 months ago
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experimental auto-currying for rust functions

• Host: GitHub
• URL: https://github.com/oppiliappan/cutlass
• Owner: oppiliappan
• License: mit
• Created: 2020-05-05T08:39:54.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2020-05-12T13:07:07.000Z (over 4 years ago)
• Last Synced: 2024-10-01T15:44:09.814Z (3 months ago)
• Language: Rust
• Homepage: https://crates.io/crates/cutlass
• Size: 4.88 KB
• Stars: 32
• Watchers: 3
• Forks: 3
• Open Issues: 1
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE

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README

        
# cutlass

> experimental auto-currying for rust functions

### example

this currently works only on nightly with the

`type_alias_impl_trait` feature enabled.

```rust

#![feature(type_alias_impl_trait)]

#[cutlass::curry]

fn add(x: u32, y: u32, z: u32) -> u32 {

    return x + y + z;

}

fn main() {

    let plus_3 = add(1)(2);

    let v: Vec = (1..=3).map(plus_3).collect();

    assert_eq!(v, vec![4, 5, 6]);

}

```

### how it works

the `#[curry]` proc-macro expands the above `add` function to

something like this (roughly):

```rust

type T0 = u32;

type T1 = impl Fn(u32) -> T0;

type T2 = impl Fn(u32) -> T1;

fn add(x: u32) -> T2 {

    return (move |y| move |z| x + y + z);

}

```

### gotchas

 - doesn't yet work for method functions (signatures with

   `self`)

 - the function has to have a return value

 - works only on nightly with `type_alias_impl_trait`

   enabled

### testing

test this crate with `cargo +nightly test`. 

to view macro expansions, install `cargo-expand` and run `cargo expand

--test `. expand `tests/smoke.rs` for example:

```

cargo expand --test smoke

```