Copyright	(c) The University of Glasgow 2001
License	BSD-style (see the file libraries/base/LICENSE)
Maintainer	[email protected]
Stability	experimental
Portability	portable
Safe Haskell	Trustworthy
Language	Haskell2010

The Dynamic type

data Dynamic where Source

A value of type Dynamic is an object encapsulated together with its type.

A Dynamic may only represent a monomorphic value; an attempt to create a value of type Dynamic from a polymorphically-typed expression will result in an ambiguity error (see toDyn).

Showing a value of type Dynamic returns a pretty-printed representation of the object's type; useful for debugging.

Converting to and from Dynamic

toDyn :: Typeable a => a -> Dynamic Source

Converts an arbitrary value into an object of type Dynamic.

The type of the object must be an instance of Typeable, which ensures that only monomorphically-typed objects may be converted to Dynamic. To convert a polymorphic object into Dynamic, give it a monomorphic type signature. For example:

   toDyn (id :: Int -> Int)

fromDyn Source

Converts a Dynamic object back into an ordinary Haskell value of the correct type. See also fromDynamic.

fromDynamic Source

Converts a Dynamic object back into an ordinary Haskell value of the correct type. See also fromDyn.

Applying functions of dynamic type

dynApply :: Dynamic -> Dynamic -> Maybe Dynamic Source

dynApp :: Dynamic -> Dynamic -> Dynamic Source

dynTypeRep :: Dynamic -> SomeTypeRep Source

Convenience re-exports

class Typeable (a :: k) Source

The class Typeable allows a concrete representation of a type to be calculated.