compiler/types

Contents:

• compiler/types/Class.hs
  • Note [Associated type defaults]
  • Note [Associated type tyvar names]
• compiler/types/CoAxiom.hs
  • Note [Coercion axiom branches]
  • Note [Branched axioms]
  • Note [Storing compatibility]
  • Note [CoAxiom saturation]
  • Note [CoAxBranch type variables]
  • Note [CoAxBranch roles]
  • Note [CoAxiom locations]
  • Note [Implicit axioms]
  • Note [Eta reduction for data families]
• compiler/types/Coercion.hs
  • Note [Function coercions]
  • Note [Pushing a coercion into a pi-type]
  • Note [Role twiddling functions]
  • Note [mkCoVarCo]
  • Note [Lifting coercions over types: liftCoSubst]
  • Note [extendLiftingContextEx]
  • Note [liftCoSubstTyVar]
  • Note [Nested ForAllCos]
  • Note [Nested InstCos]
  • Note [simplifyArgsWorker]
  • Note [Last case in simplifyArgsWorker]
• compiler/types/FamInstEnv.hs
  • Note [FamInsts and CoAxioms]
  • Note [Arity of data families]
  • Note [Lazy axiom match]
  • Note [FamInstEnv]
  • Note [Varying number of patterns for data family axioms]
  • Note [FamInstEnv determinism]
  • Note [Apartness]
  • Note [Compatibility]
  • Note [Compatibility of eta-reduced axioms]
  • Note [Tidy axioms when we build them]
  • Note [Always number wildcard types in CoAxBranch]
  • Note [Verifying injectivity annotation]
  • Note [Family instance overlap conflicts]
  • Note [Over-saturated matches]
  • Note [Normalising types]
  • Note [Normalisation and type synonyms]
  • Note [Flattening]
• compiler/types/InstEnv.hs
  • Note [ClsInst laziness and the rough-match fields]
  • Note [Template tyvars are fresh]
  • Note [Proper-match fields]
  • Note [Haddock assumptions]
  • Note [When exactly is an instance decl an orphan?]
  • Note [InstEnv determinism]
  • Note [Instance lookup and orphan instances]
  • Note [Rules for instance lookup]
  • Note [Overlapping instances] (NB: these notes are quite old)
  • Note [DFunInstType: instantiating types]
  • Note [Incoherent instances]
  • Note [Binding when looking up instances]
• compiler/types/Kind.hs
  • Note [Kind Constraint and kind Type]
• compiler/types/OptCoercion.hs
  • Note [Optimising coercion optimisation]
  • Note [Optimising InstCo]
  • Note [Optimise CoVarCo to Refl]
  • Note [Conflict checking with AxiomInstCo]
  • Note [Why call checkAxInstCo during optimisation]
  • Note [EtaAppCo]
  • Note [Eta for AppCo]
• compiler/types/TyCoRep.hs
  • Note [The Type-related module hierarchy]
  • Note [ATyCon for classes]
  • Note [Function types]
  • Note [Types for coercions, predicates, and evidence]
  • Note [Constraints in kinds]
  • Note [Arguments to type constructors]
  • Note [Non-trivial definitional equality]
  • Note [Respecting definitional equality]
  • Note [Unused coercion variable in ForAllTy]
  • Note [TyCoBinders]
  • Note [VarBndrs, TyCoVarBinders, TyConBinders, and visibility]
  • Note [No Required TyCoBinder in terms]
  • Note [Refl invariant]
  • Note [Generalized reflexive coercion]
  • Note [Coercion axioms applied to coercions]
  • Note [CoAxiom index]
  • Note [Forall coercions]
  • Note [Predicate coercions]
  • Note [Roles]
  • Note [TyConAppCo roles]
  • Note [NthCo and newtypes]
  • Note [NthCo Cached Roles]
  • Note [InstCo roles]
  • Note [Phantom coercions]
  • Note [Coercion holes]
  • Note [CoercionHoles and coercion free variables]
  • Note [ProofIrrelProv]
  • Note [Free variables of types]
  • Note [Closing over free variable kinds]
  • Note [CoVarsOfX and the InterestingVarFun]
  • Note [When does a tycon application need an explicit kind signature?]
  • Note [The substitution invariant]
  • Note [Substitutions apply only once]
  • Note [Extending the TvSubstEnv]
  • Note [Substituting types and coercions]
  • Note [Sym and ForAllCo]
  • Note [Substituting in a coercion hole]
  • Note [When to print foralls]
  • Note [Infix type variables]
• compiler/types/TyCon.hs
  • Note [Type synonym families]
  • Note [Data type families]
  • Note [Associated families and their parent class]
  • Note [TyCon Role signatures]
  • Note [Unboxed tuple RuntimeRep vars]
  • Note [Injective type families]
  • Note [AnonTCB InivsArg]
  • Note [Building TyVarBinders from TyConBinders]
  • Note [The binders/kind/arity fields of a TyCon]
  • Note [Closed type families]
  • Note [Promoted data constructors]
  • Note [Enumeration types]
  • Note [Newtype coercions]
  • Note [Newtype eta]
  • Note [Product types]
  • Note [Constructor tag allocation]
  • Note [Expanding newtypes and products]
  • Note [Skolem abstract data]
• compiler/types/Type.hs
  • Note [coreView vs tcView]
  • Note [Efficiency for mapCoercion ForAllCo case]
  • Note [Specialising mappers]
  • Note [Decomposing fat arrow c=>t]
  • Note [Representation of function types]
  • Note [Care with kind instantiation]
  • Note [mkLamType: dictionary arguments]
  • Note [Evidence for quantified constraints]
  • Note [Dictionary-like types]
  • Note [ScopedSort]
  • Note [Excess polymorphism and join points]
  • Note [Equality on AppTys]
  • Note [nonDetCmpType nondeterminism]
  • Note [typeKind vs tcTypeKind]
  • Note [Kinding rules for types]
  • Note [Phantom type variables in kinds]
  • Note [Occurs check expansion]
• compiler/types/Unify.hs
  • Note [tcMatchTy vs tcMatchTyKi]
  • Note [Pruning dead case alternatives]
  • Note [Fine-grained unification]
  • Note [The substitution in MaybeApart]
  • Note [Unifying with skolems]
  • Note [Non-idempotent substitution]
  • Note [Finding the substitution fixpoint]
  • Note [Specification of unification]
  • Note [Self-substitution when matching]
  • Note [Matching coercion variables]
  • Note [Kind coercions in Unify]
  • Note [Matching in the presence of casts]
  • Note [Polykinded tycon applications]