oo-prototypes-0.1.0.0: Support for OO-like prototypes
LicenseGPL-2
Maintainer[email protected]
Stabilityexperimental
Portabilityportable
Safe HaskellSafe-Inferred
LanguageHaskell2010

Data.Prototype

Description

Support for OO-like prototypes.

Synopsis

Documentation

newtype Proto a Source #

A prototype. Typically the parameter will be a record type. Fields can be defined in terms of others fields, with the idea that some of these definitons can be overridden.

Example:

data O = O {f1, f2, f3 :: Int}
    deriving Show
o1 = Proto $ \self -> O
  {
   f1 = 1,
   f2 = f1 self + 1,  -- 'f1 self' refers to the overriden definition of f1
   f3 = f1 self + 2
  }

Calling extractValue o1 would then produce O {f1 = 1, f2 = 2, f3 = 3}.

Constructors

Proto 

Fields

extractValue :: Proto t -> t Source #

Get the value of a prototype. This can return bottom in case some fields are recursively defined in terms of each other.

override :: Proto a -> (a -> a -> a) -> Proto a Source #

Override a prototype. Fields can be defined in terms of their definition in the base prototype.

Example:

o2 = o1 `override` \super self -> super
   {
   f1 = f1 super + 10,
   f3 = f3 super + 1
   }

(.->) :: Proto t -> (t -> a) -> a Source #

Field access