Agda.TypeChecking.CheckInternal

A bidirectional type checker for internal syntax.

Performs checking on unreduced terms. With the exception that projection-like function applications have to be reduced since they break bidirectionality.

Documentation

checkType :: Type -> TCM ()

Entry point for e.g. checking WithFunctionType.

checkType' :: Type -> TCM Sort

Check a type and infer its sort.

Necessary because of PTS rule (SizeUniv, Set i, Set i) but SizeUniv is not included in any Set i.

This algorithm follows Abel, Coquand, Dybjer, MPC 08, Verifying a Semantic βη-Conversion Test for Martin-Löf Type Theory

checkSort :: Action -> Sort -> TCM Sort

Check if sort is well-formed.

checkInternal :: Term -> Type -> TCM ()

Entry point for term checking.

checkInternal' :: Action -> Term -> Type -> TCM Term

data Action

checkInternal traverses the whole Term, and we can use this traversal to modify the term.

Constructors

Action

Fields

• preAction :: Type -> Term -> TCM Term

  Called on each subterm before the checker runs.

• postAction :: Type -> Term -> TCM Term

  Called on each subterm after the type checking.

• relevanceAction :: Relevance -> Relevance -> Relevance

  Called for each ArgInfo. The first Relevance is from the type, the second from the term.

defaultAction :: Action

The default action is to not change the Term at all.

eraseUnusedAction :: Action

infer :: Term -> TCM Type

Infer type of a neutral term.

inferSort :: Term -> TCM Sort

Compute the sort of a type.

shouldBeSort :: Type -> TCM Sort

Result is in reduced form.