Draft:Pony (programming language)

Pony
Paradigm	Actor model, Object-oriented, Imperative
Designed by	Sylvan Clebsch
First appeared	November 9, 2012; 12 years ago
Stable release	0.58.5 / June 1, 2024; 6 months ago
Typing discipline	strong, static, inferred, nominal, structural
Implementation language	C
License	BSD-2.
Website	www.ponylang.org
Influenced by
	E
Influenced
	Encore, Project Verona, Savi, Inko

Pony (sometimes referred to as ponylang) is a free and open source, object-oriented, actor model, capabilities-secure, high performance programming language. Pony's reference capabilities allow even mutable data to be safely passed by reference between actors. Garbage collection is performed concurrently, per-actor, without the need to "stop the world".

Language design

At its core, Pony is a systems language designed around safety and performance.

Safety

Type Safety - Pony is a type safe language.^[3]
Memory Safety - There are no dangling pointers and no buffer overruns. There is no null but optional types can be safely represented using unions with the None type.
Exception Safety - There are no runtime exceptions. All exceptions have defined semantics and they are always caught.
Concurrency Safety - The type system employs reference capabilities^[4] to ensure (at compile time) that your program is free of data races and deadlocks.

Performance

Lock-Free - By design, Pony avoids the need for traditional locking mechanisms, which eliminates the overhead and contention associated with locks.
Native Code - Pony is an ahead-of-time (AOT) compiled language. There is no interpreter or virtual machine
Concurrent Garbage Collection - Each actor's heap is collected separately and concurrently, avoiding the need to "stop the world" for global collection.

Examples

A few examples of idiomatic Pony follow.

Hello World

In Pony, instead of a main function, there is a main actor. The creation of this actor serves as the entry point into the Pony program.

actor Main
  new create(env: Env) =>
    env.out.print("Hello, world!")

There are no global variables in Pony, everything must be contained within an instance of a class or an actor. As such, even the environment that allows for printing to stdout is passed as a parameter.

References

^ https://github.com/ponylang/ponyc/blob/master/LICENSE
^ "Verona FAQ". Github.
^ https://www.ponylang.org/media/papers/fast-cheap.pdf
^ Sylvan Clebsch, Sophia Drossopoulou, Sebastian Blessing, Andy McNeil (October 2015). "Deny capabilities for safe, fast actors". In Elisa Gonzalez Boix, Philipp Haller, Alessandro Ricci, Carlos Varela (ed.). AGERE! 2015: Proceedings of the 5th International Workshop on Programming Based on Actors, Agents, and Decentralized Control. Pittsburgh, PA, USA: Association for Computing Machinery. pp. 1–12. doi:10.1145/2824815.2824816. ISBN 9781450339018.{{cite conference}}: CS1 maint: multiple names: authors list (link)

External links

[1] ttps://github.com/ponylang/ponyc/blob/master/LICENSE

[2] "Verona FAQ". Github.

[3] ttps://www.ponylang.org/media/papers/fast-cheap.pdf

[4] Sylvan Clebsch, Sophia Drossopoulou, Sebastian Blessing, Andy McNeil (October 2015). "Deny capabilities for safe, fast actors". In Elisa Gonzalez Boix, Philipp Haller, Alessandro Ricci, Carlos Varela (ed.). AGERE! 2015: Proceedings of the 5th International Workshop on Programming Based on Actors, Agents, and Decentralized Control. Pittsburgh, PA, USA: Association for Computing Machinery. pp. 1–12. doi:10.1145/2824815.2824816. ISBN 9781450339018.{{cite conference}}: CS1 maint: multiple names: authors list (link)

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