reader package:protolude
Retrieves a function of the current environment.
The parameterizable reader monad.
Computations are functions of a shared environment.
The
return function ignores the environment, while
>>= passes the inherited environment to both
subcomputations.
The reader monad transformer, which adds a read-only environment to
the given monad.
The
return function ignores the environment, while
>>= passes the inherited environment to both
subcomputations.
See examples in
Control.Monad.Reader. Note, the partially
applied function type
(->) r is a simple reader monad. See
the
instance declaration below.
Runs a
Reader and extracts the final value from it. (The
inverse of
reader.)