ssf

ssf is a structurally-typed strict functional core language supposed to be used as a target language for high-level strict functional programming languages.

This repository consists of two crates of ssf and ssf-llvm. The former is to construct intermediate representation (IR) of ssf going through type check and other validation and the latter is to compile it into LLVM IR bitcode.

Install

In your Cargo.toml,

ssf = { git = "https://github.com/raviqqe/ssf", branch = "master" }
ssf-llvm = { git = "https://github.com/raviqqe/ssf", branch = "master" }

Features

• Inference of closure environment types
• Partial application
• Bit cast
• Lazy evaluation

Ones not supported...

• Type inference
  • The IR needs to be fully-typed already.
• Generics
• Garbage collection
  • Bring your own GC.

Type system

• Functions
• Algebraic data types
  • Constructors are boxed or unboxed explicitly.
• Primitives
  • 8-bit integer
  • 32-bit integer
  • 64-bit integer
  • 32-bit floating point number
  • 64-bit floating point number
  • Pointer

Binary representation of ADTs

• Tags are pointer-sized integers.
• Constructor payloads boxed or unboxed contain their elements.

Single constructor with no payload

• Empty data

Single constructor with payload

| (payload size) | | -------------- | | payload |

Multiple constructors with no payload

| (pointer size) | | -------------- | | tag |

Multiple constructors with payload

| (pointer size) | (max payload size) | | -------------- | ------------------ | | tag | payload |

Examples

let algebraic_type = ssf::types::Algebraic::new(vec![ssf::types::Constructor::boxed(vec![
    ssf::types::Primitive::Float64.into(),
])]);

let bitcode = ssf_llvm::compile(
    &ssf::ir::Module::new(
        vec![],
        vec![ssf::ir::FunctionDefinition::new(
            "f",
            vec![ssf::ir::Argument::new("x", ssf::types::Primitive::Float64)],
            ssf::ir::ConstructorApplication::new(
                ssf::ir::Constructor::boxed(algebraic_type.clone(), 0),
                vec![ssf::ir::Variable("x").into()],
            ),
            algebraic_type,
        )
        .into()],
    )
    .unwrap(),
    &CompileConfiguration::new(None, None),
)?;

License

Apache 2.0