Translating Oils to Rust

Why?

Why create liboils?

• Tools like resholve are built on top of the Oils AST (lossless syntax tree), in Python
  • I'd like somebody to write an auto-formatter for YSH.
  • A formatter based on OSH is also possible, though shfmt exists (in Go)
• It would be nice to use something besides GNU readline
  • nushell and brush use the reedline create (developed as part of nushell)

Issues

• mycpp Modules
  • and refactoring to modules: the C++ build should have a pure "liboils" + the Unix I/O
• Zephyr ASDL subtyping - multiple inheritance, graph-shaped type relationships
• Python/C++ exceptions - I think every function call ends with ?
• Garbage Collection
  • Rc<T> is possible, but probably not fast, and would leak cycles
  • I would start out with Arena
  • maybe do OHeap-like "data-oriented design" - Compact AST Representation
  • later: copying collector

Non-issues:

• mycpp: classes with single inheritance should be easy

Related

Oils for Windows

Rewriting YSH Only in Rust

Oils vs. Other Bash-Compatible Shells

As of 2025, the only bash-compatible shells I know of are Oils, toysh, brush and sush.

brush and sush are much more compatible than toysh, and both are written in Rust.

• fast edit-run cycle - just start the Python interpreter (~50 ms)
• precise location info and error messages
• has YSH too
  • simple word evaluation
  • better handling
• less binary code than shells in Rust
  • though we dynamically link GNU readline, so that is not a totally fair comparison