Build.Store

An abstract key/value store.

Hashing

data Hash a

A Hash is used for efficient tracking and sharing of build results. We use newtype Hash a = Hash a for prototyping.

Instances

Functor Hash

Methods

fmap :: (a -> b) -> Hash a -> Hash b

(<$) :: a -> Hash b -> Hash a

Applicative Hash

Methods

pure :: a -> Hash a

(<*>) :: Hash (a -> b) -> Hash a -> Hash b

liftA2 :: (a -> b -> c) -> Hash a -> Hash b -> Hash c

(*>) :: Hash a -> Hash b -> Hash b

(<*) :: Hash a -> Hash b -> Hash a

Eq a => Eq (Hash a)

Methods

(==) :: Hash a -> Hash a -> Bool

(/=) :: Hash a -> Hash a -> Bool

Ord a => Ord (Hash a)

Methods

compare :: Hash a -> Hash a -> Ordering

(<) :: Hash a -> Hash a -> Bool

(<=) :: Hash a -> Hash a -> Bool

(>) :: Hash a -> Hash a -> Bool

(>=) :: Hash a -> Hash a -> Bool

max :: Hash a -> Hash a -> Hash a

min :: Hash a -> Hash a -> Hash a

Show a => Show (Hash a)

Methods

showsPrec :: Int -> Hash a -> ShowS

show :: Hash a -> String

showList :: [Hash a] -> ShowS

Hashable a => Hashable (Hash a)

Methods

hash :: Hash a -> Hash (Hash a)

class Ord a => Hashable a where

Minimal complete definition

hash

Methods

hash :: a -> Hash a

Compute the hash of a given value. We typically assume cryptographic hashing, e.g. SHA256.

Instances

Hashable Int

Methods

hash :: Int -> Hash Int

Hashable Integer

Methods

hash :: Integer -> Hash Integer

Hashable a => Hashable [a]

Methods

hash :: [a] -> Hash [a]

Hashable a => Hashable (Hash a)

Methods

hash :: Hash a -> Hash (Hash a)

(Hashable a, Hashable b) => Hashable (a, b)

Methods

hash :: (a, b) -> Hash (a, b)

Store

data Store i k v

An abstract datatype for a key/value store with build information of type i.

getValue :: k -> Store i k v -> v

Read the value of a key.

putValue :: Eq k => k -> v -> Store i k v -> Store i k v

Update the value of a key.

getHash :: Hashable v => k -> Store i k v -> Hash v

Read the hash of a key's value. In some cases may be implemented more efficiently than hash . getValue k.

getInfo :: Store i k v -> i

Read the build information.

putInfo :: i -> Store i k v -> Store i k v

Write the build information.

mapInfo :: (i -> j) -> Store i k v -> Store j k v

Modify the build information.

initialise :: i -> (k -> v) -> Store i k v

Initialise the store.