Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from http://hackage.haskell.org/package/base/docs/Data-Dynamic.html below:

Data.Dynamic

Data.Dynamic

Contents

• The Dynamic type
• Converting to and from Dynamic
• Applying functions of dynamic type
• Convenience re-exports

Description

The Dynamic interface provides basic support for dynamic types.

Operations for injecting values of arbitrary type into a dynamically typed value, Dynamic, are provided, together with operations for converting dynamic values into a concrete (monomorphic) type.

• data Dynamic where
  • Dynamic :: forall a. TypeRep a -> a -> Dynamic
• toDyn :: Typeable a => a -> Dynamic
• fromDyn :: Typeable a => Dynamic -> a -> a
• fromDynamic :: Typeable a => Dynamic -> Maybe a
• dynApply :: Dynamic -> Dynamic -> Maybe Dynamic
• dynApp :: Dynamic -> Dynamic -> Dynamic
• dynTypeRep :: Dynamic -> SomeTypeRep
• class Typeable (a :: k)

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.

Constructors

Since: base-4.0.0.0

Defined in GHC.Internal.Data.Dynamic

Methods

toException :: Dynamic -> SomeException Source #

fromException :: SomeException -> Maybe Dynamic Source #

displayException :: Dynamic -> String Source #

backtraceDesired :: Dynamic -> Bool Source #

Since: base-2.1

Defined in GHC.Internal.Data.Dynamic

Methods

showsPrec :: Int -> Dynamic -> ShowS Source #

show :: Dynamic -> String Source #

showList :: [Dynamic] -> ShowS Source #

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 #

Arguments

the dynamically-typed object

a default value

returns: the value of the first argument, if it has the correct type, otherwise the value of the second argument.

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

fromDynamic Source #

Arguments

the dynamically-typed object

returns: Just a, if the dynamically-typed object has the correct type (and a is its value), or Nothing otherwise.

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

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

dynApp :: Dynamic -> Dynamic -> Dynamic Source #

dynTypeRep :: Dynamic -> SomeTypeRep Source #

class Typeable (a :: k) Source #

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

Minimal complete definition

typeRep#

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4