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1. ReadWriteMode :: IOMode

   base	GHC.IO.IOMode

   No documentation available.

2. type ReadS a = String -> [(a, String)]

   base	GHC.Read

   A parser for a type a, represented as a function that takes a String and returns a list of possible parses as (a,String) pairs. Note that this kind of backtracking parser is very inefficient; reading a large structure may be quite slow (cf ReadP).

3. type Reader a = Text -> Either String (a, Text)

   text	Data.Text.Lazy.Read

   Read some text. If the read succeeds, return its value and the remaining text, otherwise an error message.

4. type Reader a = Text -> Either String (a, Text)

   text	Data.Text.Read

   Read some text. If the read succeeds, return its value and the remaining text, otherwise an error message.

5. module Control.Monad.Trans.Reader

   Declaration of the ReaderT monad transformer, which adds a static environment to a given monad. If the computation is to modify the stored information, use Control.Monad.Trans.State instead.

6. type Reader r = ReaderT r Identity

   transformers	Control.Monad.Trans.Reader

   The parameterizable reader monad. Computations are functions of a shared environment. The return function ignores the environment, while m >>= k passes the inherited environment to both subcomputations:

7. newtype ReaderT r (m :: Type -> Type) a

   transformers	Control.Monad.Trans.Reader

   The reader monad transformer, which adds a read-only environment to the given monad. The return function ignores the environment, while m >>= k passes the inherited environment to both subcomputations:

8. ReaderT :: (r -> m a) -> ReaderT r (m :: Type -> Type) a

   transformers	Control.Monad.Trans.Reader

   No documentation available.

9. module Control.Monad.Reader

   • Computation type: Computations which read values from a shared environment.
   • Binding strategy: Monad values are functions from the environment to a value. The bound function is applied to the bound value, and both have access to the shared environment.
   • Useful for: Maintaining variable bindings, or other shared environment.
   • Zero and plus: None.
   • Example type: Reader [(String,Value)] a
   The Reader monad (also called the Environment monad). Represents a computation, which can read values from a shared environment, pass values from function to function, and execute sub-computations in a modified environment. Using Reader monad for such computations is often clearer and easier than using the State monad. Inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

10. type Reader r = ReaderT r Identity

    mtl	Control.Monad.Reader

    The parameterizable reader monad. Computations are functions of a shared environment. The return function ignores the environment, while m >>= k passes the inherited environment to both subcomputations:

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