Data.Vault.ST

Documentation

data Vault s

A typed, persistent store for values of arbitrary types.

This variant has more complex types so that you can create keys in the ST monad. See the module Data.Vault if you'd like to use a simpler version with the IO monad. You can also use both variants simultaneously; they share a single representation.

Instances

Monoid (Vault s)

data Key s a

Keys for the vault.

empty :: Vault s

The empty vault.

newKey :: ST s (Key s a)

Create a new key for use with a vault.

lookup :: Key s a -> Vault s -> Maybe a

Lookup the value of a key in the vault.

insert :: Key s a -> a -> Vault s -> Vault s

Insert a value for a given key. Overwrites any previous value.

adjust :: (a -> a) -> Key s a -> Vault s -> Vault s

Adjust the value for a given key if it's present in the vault.

delete :: Key s a -> Vault s -> Vault s

Delete a key from the vault.

union :: Vault s -> Vault s -> Vault s

Merge two vaults (left-biased).