Microsoft Koka Programming Language vs Rust

Microsoft research developed a memory-safe language, but still using Rust to replace C++.
Interesting...

The Koka Programming Language

A Functional Language with Effect Types and Handlers

Perceus: Garbage Free Reference Counting with Reuse
Microsoft Technical Report, MSR-TR-2020-42, Nov 29, 2020, v2.

Koka and Nim are modern programming languages that use advanced reference counting memory management. Koka utilizes the Perceus compiler framework to achieve garbage-collection-free execution, while Nim implements scope-based reference counting and its own ORC collector variant. [1, 2]

Koka and Perceus

• Garbage-free design: Perceus inserts precise reference counting instructions at compile time so programs free memory instantly when references drop to zero.
• No runtime overhead: Koka compiles directly to C without a traditional garbage collector or heavy runtime system.
• Reuse analysis: The compiler detects dead objects and reuses their memory for in-place updates, enabling "functional but in-place" (FBIP) programming.
• Effect handlers: Koka tracks side effects in function types and lets users define custom control flows like async/await or exceptions safely. You can read more in The Koka Programming Language documentation. [1, 4]

Nim and Reference Counting

• Scope-based approach: Nim relies on deterministic, scope-based reference counting using non-atomic operations for high performance.
• ORC/ARC integration: Nim can use ARC (Automatic Reference Counting) or ORC (Optimized Reference Counting), which adds cycle collection to handle reference loops.
• Manual controls: Nim offers annotations like for data types and to bypass reference counting overhead on specific variables.
• Explore the community implementation guide on DEV Community.
• Discuss memory models on the Nim forum. [2, 5]

If you'd like, let me know:

• Are you planning a project using Koka's effect handlers or Nim's system programming features?
• Would you like a code example demonstrating memory reuse or effect handling?

AI responses may include mistakes.

[1] https://koka-lang.github.io/koka/doc/book.html

[2] https://forum.nim-lang.org/t/7250

[3] https://www.microsoft.com/en-us/research/wp-content/uploads/2020/11/perceus-tr-v4.pdf

[4] https://discourse.haskell.org/t/perceus-reference-counting-memory-management-and-haskell/6690

[5] https://dev.to/raviqqe/implementing-the-perceus-reference-counting-gc-5662