Ceu is a synchronous programming language that reconciles Structured Concurrency with Event-Driven Programming. Ceu extends classical structured programming with three main functionalities:

• Structured Deterministic Concurrency:
  • A set of structured primitives to compose concurrent tasks (e.g., spawn, par-or, toggle).
  • A synchronous and deterministic scheduling policy, which provides predictable behavior and safe abortion of tasks.
  • A container primitive to hold dynamic tasks, which automatically releases them on termination.
• Event Signaling Mechanisms:
  • An await primitive to suspend a task and wait for events.
  • A broadcast primitive to signal events and awake awaiting tasks.
• Lexical Memory Management:
  • Even dynamic allocation is attached to lexical blocks.
  • Strict escaping rules to preserve structure reasoning.
  • Garbage collection restricted to local references only.

Ceu is inspired by Esterel and Lua.

Follows a summary of the main ideas in the design of Ceu:

• https://github.com/fsantanna/dceu/blob/main/doc/manual-out.md#1-design

Follows an extended list of functionalities in Ceu:

• Dynamic typing
• Expression based (statements are expressions)
• Stackless coroutines (the basis of tasks)
• Restricted closures (upvalues must be explicit and final)
• Deferred statements (for finalization)
• Exception handling
• Dynamic collections (tuples, vectors, and dictionaries)
• Hierarchical tuple templates (for data description)
• Seamless integration with C (source-level compatibility)

Ceu is in experimental stage. Both the compiler and runtime can become very slow.

• https://github.com/fsantanna/dceu/blob/main/doc/manual-out.md

1. Install gcc and java:

$ sudo apt install gcc default-jre

2. Install ceu:

$ wget https://github.com/fsantanna/dceu/releases/download/v0.1.0/install-v0.1.0.sh
$ sh install-v0.1.0.sh ./ceu/

• You may want to
  • add ./ceu/ to your PATH
  • modify ./ceu/ to another destination

3. Execute ceu:

$ ./ceu/ceu ./ceu/hello-world.ceu
[0,hello]
[1,world]

The best way to try Ceu is through pico-ceu, a graphical library based on SDL:

1. Install SDL:

$ sudo apt install libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev libsdl2-gfx-dev

1. Clone pico-ceu:

$ cd ceu/
$ git clone https://github.com/fsantanna/pico-ceu pico/

2. Clone pico-sdl:

$ cd pico/
$ git clone https://github.com/fsantanna/pico-sdl sdl/

3. Execute pico-ceu:

$ cd ../../ # back to your initial working directory
$ ./ceu/ceu --lib=pico ./ceu/pico/tst/par.ceu

• Your directory hierarchy should become as follows:

+ ceu/
|---+ pico/
    |---+ sdl/

• A toy Problem: Drag, Click, or Cancel
  • https://fsantanna.github.io/toy.html
  • Run with pico-ceu:
    • ceu --lib=pico ./ceu/pico/tst/click-drag-cancel.ceu
• Comparison with JS generators:
  • https://github.com/fsantanna/dceu/blob/main/src/test/kotlin/xceu/TXJS.kt
• A simple but complete 2D game in Ceu:
  • https://github.com/fsantanna/pico-ceu-rocks
  • Clone, cd to it, and run with pico-ceu:
    • ceu --lib=pico main.ceu