r3blrsutils

• Usage
• redux
• Macros
  • Declarative
  • debug!
  • Procedural
  • #[derive(Builder)]
  • makestructsafetoshareandmutate!
• treememoryarena (non-binary tree data structure)
• utils
  • LazyMemoValues
  • tty
  • safeunwrap
  • colortext
• tui (experimental)
• Stability

This library provides utility functions:

1. Thread safe asynchronous Redux library (uses Tokio to run subscribers and middleware in separate tasks). The reducer functions are run in sequence (not in Tokio tasks).
2. Declarative macros, and procedural macros (both function like and derive) to avoid having to write lots of boilerplate code for many common (and complex) tasks.
3. Non binary tree data structure inspired by memory arenas, that is thread safe and supports parallel tree walking.
4. Functions to unwrap deeply nested objects inspired by Kotlin scope functions.
5. Capabilities to make it easier to build TUIs (Text User Interface apps) in Rust. This is currently experimental and is being actively developed.

💡 To learn more about this library, please read how it was built on developerlife.com:

1. https://developerlife.com/2022/02/24/rust-non-binary-tree/
2. https://developerlife.com/2022/03/12/rust-redux/
3. https://developerlife.com/2022/03/30/rust-proc-macro/

💡 You can also read all the Rust content on developerlife.com here. Also, the equivalent of this library is available for TypeScript and is called r3bl-ts-utils.

Usage

Please add the following to your Cargo.toml file:

toml [dependencies] r3bl_rs_utils = "0.7.7"

redux

Store is thread safe and asynchronous (using Tokio). The middleware and subscribers will be run in asynchronously via Tokio tasks. But the reducer functions will be run in sequence (not in separate Tokio tasks).

⚡ Any functions or blocks that you write which uses the Redux library will have to be marked async as well. And you will have to spawn the Tokio runtime by using the #[tokio::main] macro. If you use the default runtime then Tokio will use multiple threads and its task stealing implementation to give you parallel and concurrent behavior. You can also use the single threaded runtime; its really up to you.

Here's an example of how to use it. Let's say we have the following action enum, and state struct.

```rust /// Action enum.

[derive(Debug, PartialEq, Eq, Hash, Clone)]

pub enum Action { Add(i32, i32), AddPop(i32), Clear, MiddlewareCreateClearAction, }

/// State.

[derive(Clone, Default, PartialEq, Debug, Hash)]

pub struct State { pub stack: Vec, } ```

Here's an example of the reducer function.

rust // Reducer function (pure). let reducer_fn = |state: &State, action: &Action| match action { Action::Add(a, b) => { let sum = a + b; State { stack: vec![sum] } } Action::AddPop(a) => { let sum = a + state.stack[0]; State { stack: vec![sum] } } Action::Clear => State { stack: vec![] }, _ => state.clone(), };

Here's an example of an async subscriber function (which are run in parallel after an action is dispatched). The following example uses a lambda that captures a shared object. This is a pretty common pattern that you might encounter when creating subscribers that share state in your enclosing block or scope.

rust // This shared object is used to collect results from the subscriber function & test it later. let shared_object = Arc::new(Mutex::new(Vec::<i32>::new())); // This subscriber function is curried to capture a reference to the shared object. let subscriber_fn = with(shared_object.clone(), |it| { let curried_fn = move |state: State| { let mut stack = it.lock().unwrap(); stack.push(state.stack[0]); }; curried_fn });

Here are two types of async middleware functions. One that returns an action (which will get dispatched once this middleware returns), and another that doesn't return anything (like a logger middleware that just dumps the current action to the console). Note that both these functions share the shared_object reference from above.

```rust // This middleware function is curried to capture a reference to the shared object. let mwreturnsnone = with(sharedobject.clone(), |it| { let curriedfn = move |action: Action| { let mut stack = it.lock().unwrap(); match action { Action::Add(, _) => stack.push(-1), Action::AddPop() => stack.push(-2), Action::Clear => stack.push(-3), _ => {} } None }; curried_fn });

// This middleware function is curried to capture a reference to the shared object. let mwreturnsaction = with(sharedobject.clone(), |it| { let curriedfn = move |action: Action| { let mut stack = it.lock().unwrap(); match action { Action::MiddlewareCreateClearAction => stack.push(-4), _ => {} } Some(Action::Clear) }; curried_fn }); ```

Here's how you can setup a store with the above reducer, middleware, and subscriber functions.

rust // Setup store. let mut store = Store::<State, Action>::new(); store .add_reducer(ShareableReducerFn::new(reducer_fn)) .await .add_subscriber(SafeSubscriberFnWrapper::new(subscriber_fn)) .await .add_middleware(SafeMiddlewareFnWrapper::new(mw_returns_none)) .await;

Finally here's an example of how to dispatch an action in a test. You can dispatch actions asynchronously using dispatch_spawn() which is "fire and forget" meaning that the caller won't block or wait for the dispatch_spawn() to return. Then you can dispatch actions synchronously if that's what you would like using dispatch().

```rust // Test reducer and subscriber by dispatching Add and AddPop actions asynchronously. store.dispatchspawn(Action::Add(10, 10)).await; store.dispatch(&Action::Add(1, 2)).await; asserteq!(sharedobject.lock().unwrap().pop(), Some(3)); store.dispatch(&Action::AddPop(1)).await; asserteq!(sharedobject.lock().unwrap().pop(), Some(21)); store.clearsubscribers().await;

// Test async middleware: mwreturnsaction. sharedobject.lock().unwrap().clear(); store .addmiddleware(SafeMiddlewareFnWrapper::new(mwreturnsaction)) .dispatch(&Action::MiddlewareCreateClearAction) .await; asserteq!(store.getstate().stack.len(), 0); asserteq!(sharedobject.lock().unwrap().pop(), Some(-4)); ```

Macros

Declarative

There are quite a few declarative macros that you will find in the library. They tend to be used internally in the implementation of the library itself. Here are some that are actually externally exposed via #[macro_export].

debug!

This is a really simple macro to make it effortless to use the color console logger. It takes an identifier as an argument. It simply dumps an arrow symbol, followed by the identifier (stringified) along with the value that it contains (using the Debug formatter). All of the output is colorized for easy readability. You can use it like this.

rust let my_string = "Hello World!"; debug!(my_string);

Procedural

All the procedural macros are organized in 3 crates using an internal or core crate: the public crate, an internal or core crate, and the proc macro crate.

#[derive(Builder)]

This derive macro makes it easy to generate builders when annotating a struct or enum. It generates It has full support for generics. It can be used like this.

```rust

[derive(Builder)]

struct Point where X: std::fmt::Display + Clone, Y: std::fmt::Display + Clone, { x: X, y: Y, }

let mypt: Point = PointBuilder::new() .setx(1 as i32) .set_y(2 as i32) .build();

asserteq!(mypt.x, 1); asserteq!(mypt.y, 2); ```

makestructsafetoshareandmutate!

This function like macro (with custom syntax) makes it easy to manage shareability and interior mutability of a struct. We call this pattern the "manager" of "things").

🪄 You can read all about it here.

1. This struct gets wrapped in a RwLock for thread safety.
2. That is then wrapped inside an Arc so we can share it across threads.
3. Additionally it works w/ Tokio so that it is totally async. It also fully supports generics and trait bounds w/ an optional where clause.

Here's a very simple usage:

rust make_struct_safe_to_share_and_mutate! { named MyMapManager<K, V> where K: Default + Send + Sync + 'static, V: Default + Send + Sync + 'static containing my_map of_type std::collections::HashMap<K, V> }

Here's an async example.

```rust

[tokio::test]

async fn testcustomsyntaxnowhereclause() { makestructsafetoshareandmutate! { named StringMap // where is optional and is missing here. containing mymap of_type std::collections::HashMap }

let mymanager: StringMap = StringMap::default(); let lockedmap = mymanager.mymap.read().await; asserteq!(lockedmap.len(), 0); drop(locked_map); } ```

makesafeasyncfnwrapper!

This function like macro (with custom syntax) makes it easy to share functions and lambdas that are async. They should be safe to share between threads and they should support either being invoked or spawned.

🪄 You can read all about how to write proc macros here.

1. A struct is generated that wraps the given function or lambda in an Arc<RwLock<>> for thread safety and interior mutability.
2. A get() method is generated which makes it possible to share this struct across threads.
3. A from() method is generated which makes it easy to create this struct from a function or lambda.
4. A spawn() method is generated which makes it possible to spawn the enclosed function or lambda asynchronously using Tokio.
5. An invoke() method is generated which makes it possible to invoke the enclosed function or lambda synchronously.

Here's an example of how to use this macro.

```rust use r3blrsutils::makesafeasyncfnwrapper;

makesafeasyncfnwrapper! { named SafeMiddlewareFnWrapper containing fnmut oftype FnMut(A) -> Option } ```

let result_node_list = thread_handle.join().unwrap();
println!("{:#?}", result_node_list);

let result_node_list = thread_handle.join().unwrap();
println!("{:#?}", result_node_list);