4 releases
Uses old Rust 2015
0.1.3  Sep 28, 2016 

0.1.2  Sep 20, 2016 
0.1.1  Sep 16, 2016 
0.1.0  Sep 16, 2016 
#657 in Rust patterns
34 downloads per month
Used in functils
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Kinder
Algebraic structure and emulation of higherorder types for Rust
Kinder provides some tools and traits that functional programmers use daily.
Kinder is very much a work in progress. The idea is to make HOT's approachable to rustaceans and provide a series of macros that make implementation of custom HOTs as painless as possible.
Updates: Moved all macros to lift.rs for ease of use.
To Do

Finish implementation of Monad for std::collections 
Implement Applicative for std::collections 
Implement Traverable for std::collections (
implement Foldable first) 
Work on macros which make deriving these traits for custom types easy

Figure out how to implement Applicative for structs requiring Ord or Hash (the apply method is the issue, e.g what is an ordered function?)
The Lift Module
The lift module defines the Higher struct which allows creation of higher kinded types. It also exports the macro lift! which implements Higher for types of kind * > *.
The SemiGroup Module
Implements SemiGroup for std::collections as well as String. Provides a method add which takes two items of the same type and returns an element of the same type.
The Monoid Module
Implements Monoid for std::collections as well as String. Provides and id method for SemiGroups such that x.add(T::id()) = x.
The Foldable Module
Implements Foldable for std::collections. Provides a method foldr which takes a starting value and a function and folds the Foldable using the function. See examples for more information.
The Functor Module
Implements Functor for std::collections and exports a macro functorize! which makes a functor out of any lifted type which implements iter.
The Applicative Module
Implements Applicative for std::collections which supplies two methods. Raise takes a T and raises it to be an A, i.e Vec::lift(1) = vec!(1). Apply takes an applicative, and a lifted functions and applies it, i.e vec!(1,2).apply(vec!(x x+1, x x*x)) = vec!(2, 4).
The Monad Module
Implements Monad for std::collections. Monads have two functions, lift (normally return but return is reserved in Rust), and bind. Lift takes and element and "lifts" it into the Monad, for example Option::lift(2) = Some(2). Bind is similar to fmap except the mapping function has type: A > M<B> i.e i32 > Option<i32>. Bind is often implemented using flat_map.
Example generic summing of Vectors:
extern crate kinder;
use kinder::lift::{Foldable, Monoid};
fn sum_foldable<B: Monoid<A=B>, T: Foldable<A=B>>(xs : &T) > B
{
xs.foldr(B::id(), x, y x.add(y))
}
fn main() {
let ints = vec!(1,2,3);
let floats = vec!(1.0,2.0,3.0);
let strings = vec!(String::from("Hello"), String::from(", "), String::from("World!"));
println!("{}", sum_foldable(&ints)); //prints 6
println!("{}", sum_foldable(&floats)); //prints 6
println!("{}", sum_foldable(&strings)); //prints "Hello, World!"
}
Run this example with:
cargo run example foldexample
Example generic square function, credit to /u/stevenportzer on reddit for debugging and making the types work, run with
cargo run example funcexample
extern crate kinder;
use kinder::lift::Functor;
use std::ops::Mul;
fn squares<A: Mul<Output=A> + Clone, T: Functor<A, B=A, C=T>>(xs: &T) > T {
xs.fmap(&x x*x)
}
fn main() {
prinln!("{:?}", squares(&vec!(1,2,3))); //will print [1, 4, 9]
}