CakeML is a verified implementation of a significant subset of Standard ML.

The source and proofs for CakeML are developed in the HOL4 theorem prover. We use the latest development version of HOL4, which we build on PolyML 5.6. Example build instructions can be found in build-instructions.sh.

The master branch contains the latest development version of CakeML. See the version1 branch for the previous version.

COPYING: CakeML Copyright Notice, License, and Disclaimer.

basis: Contains the beginnings of a standard basis library for CakeML, similar to the standard basis library of SML.

build-instructions.sh: This script installs Poly/ML, HOL and CakeML.

candle: Verification of a HOL theorem prover, based on HOL Light (http://www.cl.cam.ac.uk/~jrh13/hol-light/), implemented in CakeML.

characteristic: A verified CakeML adaption of Arthur Charguéraud's "Characteristic Formulae for the Verification of Imperative Programs"

compiler: A verified compiler for CakeML, including:

• parsing: lexer and PEG parser
• inference: type inferencer
• backend: compilation to ASM assembly language
• targets: code generation to x86, ARM, and more

developers: This directory contains scripts for automating routine tasks, e.g. for running regression tests.

documentation: Work-in-progress documentation regarding the CakeML language.

explorer: Tools for stepping through execution of the compiler from one intermediate language to the next, and pretty-printing the intermediate results. An instance is available on the CakeML website.

flame: The start of a set theory formalisation that has net yet been used.

lem_lib_stub: Empty versions of the Lem libraries (which we don't use, but building with Lem requires)

lib.lem: Extensions to Lem's built-in library to target things we need in HOL.

miscScript.sml: Miscellaneous definitions and minor lemmas used throughout the development.

mlstringScript.sml: Small theory of wrapped strings, so the translator can distinguish them from char lists and can target CakeML strings directly.

semantics: The definition of the CakeML language. The definition is (mostly) expressed in Lem (http://www.cs.kent.ac.uk/~sao/lem), but the generated HOL is also included. The directory includes definitions of:

• the concrete syntax
• the abstract syntax
• small step semantics
• big step semantics (both functional and relational)
• semantics of FFI calls
• a type system

translator: A proof-producing translator from HOL functions to CakeML.

unverified: Various unverified tools, e.g. tools for converting OCaml to CakeML and an SML version of the CakeML register allocator.