An incomplete Scheme R7RS interpreter in Rust
An incomplete attempt at a Scheme interpreter written in the Rust programming language.
TODO
- Garbage collector
- Parser
- Basic interpreter
- Byte code compiler
- Stack-based byte code VM
- Hygienic macros
- Derived expressions (e.g.
case,let,do) - Standard procedures
- REPL
See the TODO.md file for additional details.
About the name
To be completely honest, I had in mind the legendary creature of Japan, rather than the fictional female fighter, Mai Shiranui. Several of my projects are named after legendary creatures of Japan and this was just another name in the long list.
Why Rust and not Go?
The astute reader will notice that I have a similar project written in Go (bakeneko, another legendary creature from Japan). So why stop working on that one and start another in a new language? Let me count the ways...
- Rust has a richer type system
- Real enums (sum types) that can be used with pattern matching
- Go has only integers and the
iotakeyword
- Go has only integers and the
- Generics to enable honest-to-goodness reusable collections
- Avoids the dreaded
interface{}everywhere
- Avoids the dreaded
- Real enums (sum types) that can be used with pattern matching
- Rust does not have a
nilvalue, the infamous billion dollar mistake- While Rust has
(), it has its own type (unit), so cannot be used mistakenly
- While Rust has
- Rust has pattern matching which prevents missed cases
- Rust is expression oriented (i.e.
ifis an expression) - Rust uses nominal subtyping instead of structural subtyping
- Easier when reading new code, easier to maintain existing code
- Rust permits fine-grained visibility of program items via nested modules
- Additional reasons given in these well written posts:
Other Scheme interpreters in Rust
There are a ton of them, but not all of them are complete, and most are not shooting for R7RS small language completeness. Besides, this project is for fun, not novelty.