Context

R3BL TUI library & suite of apps focused on developer productivity

We are working on building command line apps in Rust which have rich text user interfaces (TUI). We want to lean into the terminal as a place of productivity, and build all kinds of awesome apps for it.

1. 🔮 Instead of just building one app, we are building a library to enable any kind of rich TUI development w/ a twist: taking concepts that work really well for the frontend mobile and web development world and re-imagining them for TUI & Rust.

• Taking inspiration from React, JSX, CSS, Redux, Elm, iced-rs, JetPack Compose, but making things fast and Rusty and simple. For example, instead of using Redux for complex state management and handling async middleware functions, we simply using tokio::mpsc channels and allow tasks to send signals to the main thread to re-render or relay these signals to the appropriate app logic.
• Even the thread running the main event loop doesn't block since it is async.
• Using proc macros to create DSLs to implement CSS & JSX.

2. 🌎 We are building apps to enhance developer productivity & workflows.

• The idea here is not to rebuild tmux in Rust (separate processes mux'd onto a single terminal window). Rather it is to build a set of integrated "apps" (or "tasks") that run in the same process that renders to one terminal window.
• Inside of this terminal window, we can implement things like "app" switching, routing, tiling layout, stacking layout, etc. so that we can manage a lot of TUI apps (which are tightly integrated) that are running in the same process, in the same window. So you can imagine that all these "app"s have shared application state (that is in a Redux store). Each "app" may also have its own Redux store.
• Here are some examples of the types of "app"s we plan to build (for which this infrastructure acts as the open source engine):
  1. Multi user text editors w/ syntax highlighting.
  2. Integrations w/ github issues.
  3. Integrations w/ calendar, email, contacts APIs.

All the crates in the r3bl-open-core repo provide lots of useful functionality to help you build TUI (text user interface) apps, along w/ general niceties & ergonomics that all Rustaceans 🦀 can enjoy 🎉:

r3bl_rs_utils crate

tree_memory_arena (non-binary tree data structure)

Arena and MTArena types are the implementation of a non-binary tree data structure that is inspired by memory arenas.

Here's a simple example of how to use the Arena type:

use r3bl_rs_utils::{
  tree_memory_arena::{Arena, HasId, MTArena, ResultUidList},
  utils::{style_primary, style_prompt},
};

let mut arena = Arena::<usize>::new();
let node_1_value = 42 as usize;
let node_1_id = arena.add_new_node(node_1_value, None);
println!("{} {:#?}", style_primary("node_1_id"), node_1_id);
assert_eq!(node_1_id, 0);

Here's how you get weak and strong references from the arena (tree), and tree walk:

use r3bl_rs_utils::{
  tree_memory_arena::{Arena, HasId, MTArena, ResultUidList},
  utils::{style_primary, style_prompt},
};

let mut arena = Arena::<usize>::new();
let node_1_value = 42 as usize;
let node_1_id = arena.add_new_node(node_1_value, None);

// Access node.
{
  assert!(arena.get_node_arc(&node_1_id).is_some());
  let node_1_ref = dbg!(arena.get_node_arc(&node_1_id).unwrap());
  let node_1_ref_weak = arena.get_node_arc_weak(&node_1_id).unwrap();
  assert_eq!(node_1_ref.read().unwrap().payload, node_1_value);
  assert_eq!(
    node_1_ref_weak.upgrade().unwrap().read().unwrap().payload,
    42
  );
}

// Node does not exist.
{
  let node_id_dne = 200 as usize;
  assert!(arena.get_node_arc(&node_id_dne).is_none());
}

// Walk tree.
{
  let node_1_id = 0 as usize;
  let node_list = dbg!(arena.tree_walk_dfs(&node_1_id).unwrap());
  assert_eq!(node_list.len(), 1);
  assert_eq!(node_list, vec![0]);
}

// Mutate node.
{
  let node_1_id = 0_usize;
  {
    let node_1_ref = dbg!(arena.get_node_arc(node_1_id).unwrap());
    node_1_ref.write().unwrap().payload = 100;
  }
  assert_eq2!(
    arena.get_node_arc(node_1_id).unwrap().read().unwrap().payload,
    100
  );
}

Here's an example of how to use the MTArena type:

use std::{
  sync::Arc,
  thread::{self, JoinHandle},
};

use r3bl_rs_utils::{
  tree_memory_arena::{Arena, HasId, MTArena, ResultUidList},
  utils::{style_primary, style_prompt},
};

type ThreadResult = Vec<usize>;
type Handles = Vec<JoinHandle<ThreadResult>>;

let mut handles: Handles = Vec::new();
let arena = MTArena::<String>::new();

// Thread 1 - add root. Spawn and wait (since the 2 threads below need the root).
{
  let arena_arc = arena.get_arena_arc();
  let thread = thread::spawn(move || {
    let mut arena_write = arena_arc.write().unwrap();
    let root = arena_write.add_new_node("foo".to_string(), None);
    vec![root]
  });
  thread.join().unwrap();
}

// Perform tree walking in parallel. Note the lambda does capture many enclosing variable context.
{
  let arena_arc = arena.get_arena_arc();
  let fn_arc = Arc::new(move |uid, payload| {
    println!(
      "{} {} {} Arena weak_count:{} strong_count:{}",
      style_primary("walker_fn - closure"),
      uid,
      payload,
      Arc::weak_count(&arena_arc),
      Arc::weak_count(&arena_arc)
    );
  });

  // Walk tree w/ a new thread using arc to lambda.
  {
    let thread_handle: JoinHandle<ResultUidList> =
      arena.tree_walk_parallel(&0, fn_arc.clone());

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

  // Walk tree w/ a new thread using arc to lambda.
  {
    let thread_handle: JoinHandle<ResultUidList> =
      arena.tree_walk_parallel(&1, fn_arc.clone());

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

📜 There are more complex ways of using Arena and MTArena. Please look at these extensive integration tests that put them thru their paces here.