seaslug

small, beautiful, knowable, DOESN'T EXIST YET LOL

• non-turing complete, verified terminating code placed into well-defined interfaces similar to Erlang behaviors
• strongly typed, powerful inference to minimize type noise
• a runtime built from the beginning to take advantage of io_uring, immutable messaging, optimistic STM, and generally paying attention to modern scheduling research
  • the runtime tracks overall utilization and saturation
  • aims to maximize utilization while minimizing saturation (writes before reads before accepts for sockets)
  • infers contention causality encountered in the optimistic state layer and learns to step in as a traffic director, letting users avoid thinking about contention
• leans into linear logic to enforce error handling in well-specified hierarchies, similar to Erlang supervisors
• interpreter-first, but the interpreter itself aims to compile quickly so you can produce static optimized native binaries (something something Futamura something...)
• built-in first-class fault injection, fuzzing, network simulation, model-based testing, and concurrent interleaving exploration
• rich built-in data structures, first-class json support, first-class binary parsing support

seaslug should be an ideal language for building

• databases
• distributed systems
• servers
• scalable concurrent systems
• multitenant infrastructure

seaslug does not aim to excel at

• building your own data structures
• intensive numerical processing
• short-lived CLI applications
• embedded programming

ideas that may or may not lead to seaslug

• erlang's terseness, behaviors, focus on immutable message passing, explicit supervisor hierarchies, pattern matching, binary parsing capabilities
• celf's nondeterminism and linear logic
• constraint handling rules's verification opportunities
• prolog's declarative debugging, tables, provability of pure code
• total functional programming's restrictions on recursion and looping

seaslug is written in rust and takes advantage of things like

• io_uring
• simdjson
• sled
• software transactional memory