Copyright	(c) 2020-2021 Tim Emiola
License	BSD3
Maintainer	Tim Emiola <adetokunbo@users.noreply.github.com>
Safe Haskell	Safe-Inferred
Language	Haskell2010

System.TmpProc.TypeLevel

Contents

Heterogenous List
A type-level Key-Value
Other combinators
Re-exports

Description

Defines type-level data structures and combinators used by System.TmpProc.Docker and System.TmpProc.Warp.

HList implements a heterogenous list used to define types that represent multiple concurrent tmp procs.

KV is intended for internal use within the tmp-proc package. It allows indexing and sorting of lists of tmp procs.

Synopsis

data HList :: [Type] -> Type where
- HNil :: HList '[]
- HCons :: anyTy -> HList manyTys -> HList (anyTy ': manyTys)
(&:) :: x -> HList xs -> HList (x ': xs)
only :: x -> HList '[x]
(&:&) :: x -> y -> HList '[x, y]
both :: x -> y -> HList '[x, y]
hHead :: HList (a ': as) -> a
hOf :: forall y xs. IsInProof y xs => Proxy y -> HList xs -> y
class ReorderH xs ys where
- hReorder :: HList xs -> HList ys
data KV :: Symbol -> Type -> Type where
- V :: a -> KV s a
select :: forall k t xs. MemberKV k t xs => HList xs -> t
selectMany :: forall ks ts xs. ManyMemberKV ks ts xs => HList xs -> HList ts
data LookupKV (k :: Symbol) t (xs :: [Type]) where
- AtHead :: LookupKV k t (KV k t ': kvs)
- OtherKeys :: LookupKV k t kvs -> LookupKV k t (KV ok ot ': kvs)
class MemberKV (k :: Symbol) (t :: Type) (xs :: [Type]) where
- lookupProof :: LookupKV k t xs
class ManyMemberKV (ks :: [Symbol]) (ts :: [Type]) (kvs :: [Type]) where
- manyProof :: LookupMany ks ts kvs
type family IsAbsent e r :: Constraint where ...
class IsInProof t (tys :: [Type])
module System.TmpProc.TypeLevel.Sort

Heterogenous List

data HList :: [Type] -> Type where Source #

Defines a Heterogenous list.

Constructors

HNil :: HList '[]
HCons :: anyTy -> HList manyTys -> HList (anyTy ': manyTys) infixr 5

Instances

Instances details

(Show x, Show (HList xs)) => Show (HList (x ': xs)) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods showsPrec :: Int -> HList (x ': xs) -> ShowS Source # show :: HList (x ': xs) -> String Source # showList :: [HList (x ': xs)] -> ShowS Source #
Show (HList ('[] :: [Type])) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods showsPrec :: Int -> HList '[] -> ShowS Source # show :: HList '[] -> String Source # showList :: [HList '[]] -> ShowS Source #
(Eq x, Eq (HList xs)) => Eq (HList (x ': xs)) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods (==) :: HList (x ': xs) -> HList (x ': xs) -> Bool Source # (/=) :: HList (x ': xs) -> HList (x ': xs) -> Bool Source #
Eq (HList ('[] :: [Type])) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods (==) :: HList '[] -> HList '[] -> Bool Source # (/=) :: HList '[] -> HList '[] -> Bool Source #

(&:) :: x -> HList xs -> HList (x ': xs) infixr 5 Source #

An infix alias for HCons.

only :: x -> HList '[x] Source #

Construct a singleton HList

(&:&) :: x -> y -> HList '[x, y] infixr 6 Source #

An infix alias for both.

both :: x -> y -> HList '[x, y] infixr 6 Source #

Construct a two-item HList.

hHead :: HList (a ': as) -> a Source #

Obtain the first element of a HList.

hOf :: forall y xs. IsInProof y xs => Proxy y -> HList xs -> y Source #

Get an item in an HList given its type.

class ReorderH xs ys where Source #

Allows reordering of similar HLists.

Examples

Expand

>>> hReorder @_ @'[Bool, Int] ('c' &: (3 :: Int) &: True &: (3.1 :: Double) &: HNil)
True &: 3 &: HNil

>>> hReorder @_ @'[Double, Bool, Int] ('c' &: (3 :: Int) &: True &: (3.1 :: Double) &: HNil)
3.1 &: True &: 3 &: HNil

Methods

hReorder :: HList xs -> HList ys Source #

Instances

Instances details

ReorderH xs ('[] :: [Type]) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods hReorder :: HList xs -> HList '[] Source #
(IsInProof y xs, ReorderH xs ys) => ReorderH xs (y ': ys) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods hReorder :: HList xs -> HList (y ': ys) Source #

A type-level Key-Value

data KV :: Symbol -> Type -> Type where Source #

Use a type-level symbol as key type that indexes a value type.

Constructors

V :: a -> KV s a

Instances

Instances details

ManyMemberKV ks ts kvs => ManyMemberKV ks ts (KV ok ot ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany ks ts (KV ok ot ': kvs) Source #
MemberKV k t '[KV k t] Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t '[KV k t] Source #
MemberKV k t (KV k t ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t (KV k t ': kvs) Source #
MemberKV k t kvs => MemberKV k t (KV ok ot ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t (KV ok ot ': kvs) Source #
ManyMemberKV '[k] '[t] (KV k t ': ks) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany '[k] '[t] (KV k t ': ks) Source #
ManyMemberKV ks ts kvs => ManyMemberKV (k ': ks) (t ': ts) (KV k t ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany (k ': ks) (t ': ts) (KV k t ': kvs) Source #

select :: forall k t xs. MemberKV k t xs => HList xs -> t Source #

Select an item from an HList of KVs by key.

N.B Returns the first item. It assumes the keys in the KV HList are unique. TODO: enforce this rule using a constraint.

Examples

Expand

>>> select @"d" @Double  @'[KV "b" Bool, KV "d" Double] (V True &:  V (3.1 :: Double) &: HNil)
3.1

selectMany :: forall ks ts xs. ManyMemberKV ks ts xs => HList xs -> HList ts Source #

Select items with specified keys from an HList of KVs by key.

N.B. this this is an internal function.

The keys must be provided in the same order as they occur in the HList, any other order will likely result in an compiler error.

Examples

Expand

>>> selectMany @'["b"] @'[Bool] @'[KV "b" Bool, KV "d" Double] (V True &:  V (3.1 :: Double) &: HNil)
True &: HNil

data LookupKV (k :: Symbol) t (xs :: [Type]) where Source #

Proves a symbol and its type occur as entry in a list of KV types.

Constructors

AtHead :: LookupKV k t (KV k t ': kvs)
OtherKeys :: LookupKV k t kvs -> LookupKV k t (KV ok ot ': kvs)

class MemberKV (k :: Symbol) (t :: Type) (xs :: [Type]) where Source #

Generate proof instances of LookupKV.

Methods

lookupProof :: LookupKV k t xs Source #

Instances

Instances details

MemberKV k t '[KV k t] Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t '[KV k t] Source #
MemberKV k t (KV k t ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t (KV k t ': kvs) Source #
MemberKV k t kvs => MemberKV k t (KV ok ot ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods lookupProof :: LookupKV k t (KV ok ot ': kvs) Source #

class ManyMemberKV (ks :: [Symbol]) (ts :: [Type]) (kvs :: [Type]) where Source #

Generate proof instances of LookupMany.

Methods

manyProof :: LookupMany ks ts kvs Source #

Instances

Instances details

ManyMemberKV ks ts kvs => ManyMemberKV ks ts (KV ok ot ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany ks ts (KV ok ot ': kvs) Source #
ManyMemberKV '[k] '[t] (KV k t ': ks) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany '[k] '[t] (KV k t ': ks) Source #
ManyMemberKV ks ts kvs => ManyMemberKV (k ': ks) (t ': ts) (KV k t ': kvs) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods manyProof :: LookupMany (k ': ks) (t ': ts) (KV k t ': kvs) Source #

Other combinators

type family IsAbsent e r :: Constraint where ... Source #

A constraint that confirms that a type is not present in a type-level list.

Equations

IsAbsent e '[] = ()
IsAbsent e (e ': _) = TypeError (NotAbsentErr e)
IsAbsent e (e' ': tail) = IsAbsent e tail

class IsInProof t (tys :: [Type]) Source #

Generate proof instances of IsIn.

Minimal complete definition

provedIsIn

Instances

Instances details

IsInProof t tys => IsInProof t (a ': tys) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods provedIsIn :: IsIn t (a ': tys)
IsInProof t (t ': tys) Source #
Instance details Defined in System.TmpProc.TypeLevel Methods provedIsIn :: IsIn t (t ': tys)

Re-exports

module System.TmpProc.TypeLevel.Sort