| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Effectful.Reader.Dynamic
Contents
Description
The dynamically dispatched variant of the Reader effect.
Note: unless you plan to change interpretations at runtime, it's recommended to use the statically dispatched variant, i.e. Effectful.Reader.Static.
Synopsis
- data Reader r :: Effect where
- runReader :: HasCallStack => r -> Eff (Reader r : es) a -> Eff es a
- withReader :: HasCallStack => (r1 -> r2) -> Eff (Reader r2 : es) a -> Eff (Reader r1 : es) a
- ask :: (HasCallStack, Reader r :> es) => Eff es r
- asks :: (HasCallStack, Reader r :> es) => (r -> a) -> Eff es a
- local :: (HasCallStack, Reader r :> es) => (r -> r) -> Eff es a -> Eff es a
Effect
data Reader r :: Effect where Source #
Instances
| type DispatchOf (Reader r) Source # | |
Defined in Effectful.Reader.Dynamic | |
Handlers
Arguments
| :: HasCallStack | |
| => r | The initial environment. |
| -> Eff (Reader r : es) a | |
| -> Eff es a |
Run the Reader effect with the given initial environment (via
Effectful.Reader.Static).
Arguments
| :: HasCallStack | |
| => (r1 -> r2) | The function to modify the environment. |
| -> Eff (Reader r2 : es) a | Computation to run in the modified environment. |
| -> Eff (Reader r1 : es) a |
Execute a computation in a modified environment.
Since: 1.1.0.0
Operations
Arguments
| :: (HasCallStack, Reader r :> es) | |
| => (r -> a) | The function to apply to the environment. |
| -> Eff es a |