Show HN: I'm making a dynamic language in Rust https://ift.tt/lfAdGk3 An implementation of a dynamic programming language in Rust. Includes: Parser/Compiler, REPL, Virtual Machine, Bytecode Disassembler This started out as a learning project to teach myself Rust. It has grown into a decently substantial piece of software and I've learned quite a bit in the process! Some neat things: + A garbage collector that can store dynamically sized types without any double-indirection (i.e. I have my own Box implementation with manual alloc/dealloc) + The smart pointer used to reference GCed data is a thin pointer. The ptr metadata needed for DSTs is stored in the GC allocation itself, so that the GC smart pointer is just a single usize wide. This allows me to keep the core value enum Variant down to 16 bytes (8 bytes for data, the enum discriminant, and some padding). + The GC also supports weak references! + Statically dispatched type object model using a newtype wrapper and Rust's declarative macros. Ok, what that means is that I have a MetaObject trait that I can use to easily add new data types and define the behavior for specific types. Similar idea to Python's PyTypeObject though very different in implementation. However, I don't resort to dynamic dispatch or trait objects despite working with dynamically type data. Instead, I have a newtype wrapper over the core value enum Variant that statically dispatches to each of the enum branches! And then a few macros that minimize the boilerplate required if I want to add a new branch to Variant or a new method to MetaObject (just a single line in each case). + Different string representations! This was inspired by the flexstr crate. Strings that are short enough to fit inside a Variant are "inlined" directly in the value. Longer strings are either GCed or interned in a thread-local string table. All identifiers are interned. + An efficient implementation of closures inspired by Lua's upvalues. The language is still pretty WIP. I'm planning to add an import system, a small standard library, and a few other things (Yes, the name might not be the best, being also used by a well-known ReST docs generator, I'll take suggestions. I do like the name though, both as a reference to the mythological creature and the cat :D) April 25, 2022 at 05:46AM
Women Pioneers at Muni: Adeline Svendsen and Muni’s First Newsletter By Jeremy Menzies To close out Women’s History Month, here’s a look back at one woman whose work to bring Muni staff together in the late 1940s created a legacy that lives on to this day. Adeline “Addy” Svendsen was founding editor of Muni’s first internal newsletter, “ Trolley Topics .” Adeline Svendsen sits at her desk in the Geneva Carhouse office building in this 1949 shot. Trolley Topics was a new venture when it started in February 1946. As Svendsen wrote in the first issue it was created, “to bring a little fun, a little news, and a lot of good will to all our fellow employees in the Railway.” Just two years prior in 1944, Muni merged with the Market Street Railway Company, expanding the small municipal operation into the largest transit provider in the city with hundreds of employees, vehicles of every shape and size, and dozens of facilities scattered across town. The newsletter was meant to help unite ...
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