Project structure

Julia project

The subfolders of the Julia part are organized as follows:

- src       (builtins and code for calling the typechecker written in Haskell)
- example   (full typecheckable and working example code)
- docs/src  (this documentation)

Haskell project

The subfolders of the Haskell part are organized as follows:

- app  (main entry point into application)
- src  (actual source code)
  \- DiffMu
     |- Prelude    (Common imports from libraries)
     |- Abstract   (Structures/Code useful for building typecheckers,
     |              should not contain references to the actual duet type system)
     |- Core       (Basic definitions of the duet type system, operations on contexts, etc.)
     |- Typecheck  (Implementation of the actual typechecking and subtyping rules)
- ffisrc      (haskell code which is the entrypoint when calling this project from julia)
- csrc        (c code fragment for initializing the haskell runtime)
- test        (place for tests which do NOT need to call julia-callbacks, i.e., currently none)
- test-native (current place for all tests which are called when executing test_hs() in julia)
- docs        (place for documentation)

In particular, in src/DiffMu/Core, we find:

• Definitions of all relevant data types, and the main typechecking monad in Definitions.hs and TC.hs, unification is found in Unification.hs
• The symbolic number data type, used for sensitivity and privacy values in Symbolic.hs
• The logging system in Logging.hs

In src/DiffMu/Typecheck, we have:

• The preprocessing steps in Preprocess:
  1. Collection of information about top-level functions (TopLevel.hs)
  2. Translating mutating code into non-mutating code (Demutation.hs)
  3. Rearranging function definitions (FLetReorder.hs)
  4. Renaming function argument names to simulate lexical scoping (LexicalScoping.hs)
• The main typechecking function in Typecheck.hs