OCaml implementation of the lox language from Crafting Interpreters (I have never used OCaml before, but I have done some work with Haskell)
Use Jane Street's style guide.
- Think about replacing the stdlib with Jane Street's Core.
- Why this needs to be thought out: I aim for this to have as few dependencies as possible, relying on easily understood OCaml code for beginners like me who are new to the language (avoiding ppx, etc)
- This also means that the code is easily to understand and avoids duplication, which I feel it does. The lexer is roughly 150 lines of code, and the parser and interpreter are roughly the same.
- Figure out a way to return lexing errors and exiting before running the parser.
- Profile the code
- Files implicitly define a module of their filename.
Lists are singly-linked, rather than a contiguous array in memory that is reallocated when full a la Rust'sVec<T>. I presume this is due to the garbage collector, where it is easier to allocate a smaller object in the nursery and point the tail node to that rather than allocating the same list again. Is this slow?- Jane Street's replacement standard libraries (Base, Core) avoid raising
exceptions unless they're postfixed with
_exn. - OCaml will automatically run any expression of type
unit, so functions called for the purpose of expressing side effects should be of prototypeunit -> unit. - There is no
>>=operator in the standard library, and thelet*syntax described in Language extensions isn't actually defined either?- Ah, it's just saying that forms of
let*bindings were allowed, not that they're defined.
- Ah, it's just saying that forms of
- I have spent way too much time refactoring code that I didn't like, instead of actually writing more code.
- When synchronizing we want to parse the whole thing, but not interpret it
- https://craftinginterpreters.com/scanning.html
- https://keleshev.com/composable-error-handling-in-ocaml
- https://cs.brown.edu/courses/cs017/content/docs/ocaml-style.pdf
- https://github.com/graydon/rust-prehistory/blob/08ba0a74a7dd74b42c967b9c0263eb63627e9bb9/src/boot/fe/lexer.mll
- https://www.cs.princeton.edu/courses/archive/fall13/cos326/lec/16b-laziness.pdf