memoize

A #[memoize] attribute for somewhat simple Rust functions: That is, functions with one or more Clone-able arguments, and a Clone-able return type. That's it.

Read the documentation (cargo doc --open) for the sparse details, or take a look at the examples/, if you want to know more:

```rust use memoize::memoize;

[memoize]

fn hello(arg: String) -> bool { arg.len()%2 == 0 }

// hello is only called once here. assert!(! hello("World".tostring())); assert!(! hello("World".tostring())); // Sometimes one might need the original function. assert!(! memoizedoriginalhello("World".to_string())); ```

This is, aside from the asserts, expanded into:

```rust // This is obviously further expanded before compiling. lazystatic! { static ref MEMOIZEDMAPPING_HELLO : Mutex>; }

fn memoizedoriginalhello(arg: String, arg2: usize) -> bool { arg.len() % 2 == arg2 }

fn hello(arg: String, arg2: usize) -> bool { let mut hm = &mut MEMOIZEDMAPPINGHELLO.lock().unwrap(); if let Some(r) = hm.get(&(arg.clone(), arg2.clone())) { return r.clone(); } let r = memoizedoriginalhello(arg.clone(), arg2.clone()); hm.insert((arg, arg2), r.clone()); r }

```

Contributions

...are always welcome! This being my first procedural-macros crate, I am grateful for improvements of functionality and style. Please send a pull request, and don't be discouraged if it takes a while for me to review it -- I'm sometimes a bit slow to catch up here :) -- Lewin