Agda.TypeChecking.Conversion

Documentation

tryConversion :: TCM () -> TCM Bool

Try whether a computation runs without errors or new constraints. Restores state upon failure.

sameVars :: Elims -> Elims -> Bool

Check if to lists of arguments are the same (and all variables). Precondition: the lists have the same length.

intersectVars :: Elims -> Elims -> Maybe [Bool]

intersectVars us vs checks whether all relevant elements in us and vs are variables, and if yes, returns a prune list which says True for arguments which are different and can be pruned.

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

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

equalType :: Type -> Type -> TCM ()

convError :: TypeError -> TCM ()

Ignore errors in irrelevant context.

compareTerm :: Comparison -> Type -> Term -> Term -> TCM ()

Type directed equality on values.

unifyPointers :: t -> t1 -> t2 -> t3 -> t3

assignE :: CompareDirection -> MetaId -> Elims -> Term -> (Term -> Term -> TCM ()) -> TCM ()

Try to assign meta. If meta is projected, try to eta-expand and run conversion check again.

compareTermDir :: CompareDirection -> Type -> Term -> Term -> TCM ()

compareTerm' :: Comparison -> Type -> Term -> Term -> TCM ()

compareTel :: Type -> Type -> Comparison -> Telescope -> Telescope -> TCM ()

compareTel t1 t2 cmp tel1 tel1 checks whether pointwise tel1 `cmp` tel2 and complains that t2 `cmp` t1 failed if not.

etaInequal :: Comparison -> Type -> Term -> Term -> TCM ()

Raise UnequalTerms if there is no hope that by meta solving and subsequent eta-contraction these terms could become equal. Precondition: the terms are in reduced form (with no top-level pointer) and failed to be equal in the compareAtom check.

By eta-contraction, a lambda or a record constructor term can become anything.

compareAtomDir :: CompareDirection -> Type -> Term -> Term -> TCM ()

compareAtom :: Comparison -> Type -> Term -> Term -> TCM ()

Syntax directed equality on atomic values

compareRelevance :: Comparison -> Relevance -> Relevance -> Bool

compareElims :: [Polarity] -> Type -> Term -> [Elim] -> [Elim] -> TCM ()

compareElims pols a v els1 els2 performs type-directed equality on eliminator spines. t is the type of the head v.

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

Compare two terms in irrelevant position. This always succeeds. However, we can dig for solutions of irrelevant metas in the terms we compare. (Certainly not the systematic solution, that'd be proof search...)

compareWithPol :: Polarity -> (Comparison -> a -> a -> TCM ()) -> a -> a -> TCM ()

compareArgs :: [Polarity] -> Type -> Term -> Args -> Args -> TCM ()

Type-directed equality on argument lists

Types

compareType :: Comparison -> Type -> Type -> TCM ()

Equality on Types

leqType :: Type -> Type -> TCM ()

coerce :: Term -> Type -> Type -> TCM Term

coerce v a b coerces v : a to type b, returning a v' : b with maybe extra hidden applications or hidden abstractions.

In principle, this function can host coercive subtyping, but currently it only tries to fix problems with hidden function types.

coerceSize :: Term -> Type -> Type -> TCM Term

Account for situations like k : (Size< j) <= (Size< k + 1)

Actually, the semantics is (Size<= k) ∩ (Size< j) ⊆ rh which gives a disjunctive constraint. Mmmh, looks like stuff TODO.

For now, we do a cheap heuristics.

Sorts and levels

compareLevel :: Comparison -> Level -> Level -> TCM ()

compareSort :: Comparison -> Sort -> Sort -> TCM ()

leqSort :: Sort -> Sort -> TCM ()

Check that the first sort is less or equal to the second.

leqLevel :: Level -> Level -> TCM ()

equalLevel :: Level -> Level -> TCM ()

equalSort :: Sort -> Sort -> TCM ()

Check that the first sort equal to the second.

Definitions

bothAbsurd :: QName -> QName -> TCM Bool