SCLPL Design Notes

Language Requirements:

• Eager Evaluation
• Single Assignment
• Dynamic Typing
• Immuatable Data Structures
• Functional Programming
• Garbage Collection
• Tail Call Optimization
• Compiled to native binaries
  • no virtual machine, C as target language
• First class parallelism/concurrency
• First class support for testing

General Info

• Erlang
  • wikipedia
  • Error handling
  • Actor model, message passing
  • Stack growing/recursion story
• Go Stack Handling
• Apple Docs/Source
  • Apple Source Repo
  • Apple Libc

Concurrency/Parallelism

• Processes
• Threads
• Tasks (coroutines)
• Communicating Sequential Processes
• Actor Model

Investigations

• makecontext/setcontext based coroutines
• raw assembly coroutines based on fcontext_t
  • makecontext/swapcontext on OSX
  • fcontext
• CSP versus Actor model

Language Design

Ideas to Explore

• Expression-only Syntax
  • Assignment operator is the only way to define variables and can be, but should not be, used as an expression.
  • The entire grammar (almost) is parsed with a Pratt parser.
• Gradually typed type system
  • Dynamically typed in absence of annotations
  • Annotations allow the compiler to utilize unchecked operations for higher performance
  • Typing would be bidirectional to allow for types to be inferred from values or bindings.
  • Would allow for unannotated expressions that are still provably safe to utilize unchecked operations
• Deferred reference counting for garbage collection.
  • Immutable bindings and data so no cycles to deal with.
  • Could use non-atomic increment/decrement and use multiprocessing instead of multithreading.

Atomic Types

• Fixnums
• Flonums
• Strings
• Symbols

Aggregate Types

• Lists
• Vectors
• Maps
• Records/Tuples?

Other Types

• Ports
• Procedures/Closures/Functions