Programatica Tools

Directory tools/base/TI

Extensible Haskell front-end for the Programatica project

What is in this directory (base/TI)

At present, the type inference monad is fixed, and the AST for inferred types is fixed, but it might be possible to factor out these aspects too.

Although various details differ, this type checker is influenced by

• Mark Jones' Typing Haskell in Haskell (general guidance, some naming conventions, the class Types and operations on substitutions, ...),
• one of Johan Nordlander's type checkers for O'Haskell (that avoids both threading an accumulating substitution and applying substitutions to the environment),
• and also somewhat by the type checker in HBC. (HBC serves as a proof that you don't need to resort to imperative unification to implement efficient type inference, nor do you need to sweep things under the carpet with a monad to make a purely functional type checker readable.)

Modules for the basic type inference machinery

• TiMonad (NewTiMonad or OrigTiMonad), TiClasses, TiConstraints, TiEnv, TiFresh, TiKinds, TiSolve, TiTypes, TiUtil, TI, TiPretty, TiNames, Unification.

Instances and context reduction

• TiBySuper, TiContextReduction, TiDefault, TiDerivedInstances, TiInstanceDB.

Type inference for the base language structure

• Declarations: TiD, TiClassInst, TiDkc,
• Expressions, patterns, etc: TiE, TiFields, TiLit,TiP, TiRhs,
• Kinds inference for type expressions: TiT,
• Modules: TiModule,
• Collects everything: TiBaseStruct.

Knot-tying definitions for the base language

• TiBase, TiDecorate, NameMapsDecorate

Type inference for sequences of declarations

• TiDs.

Interfaces to other pieces of reusable code

• TiSCC, TiDefinedNames, TiFreeNames.

Other modules

• TiPrelude, TiHsName