LGtk.ADTEditor

A generic ADT editor defined on top of the main LGtk interface, LGtk.

Documentation

newtype Lens_ a b

Constructors

Lens_

Fields

unLens_ :: Lens' a b

data List a

Type-level lists

Constructors

Nil

Cons a (List a)

data Elems xs where

Heterogeneous lists

Constructors

ElemsNil :: Elems Nil

ElemsCons :: ADTLens a => a -> Elems as -> Elems (Cons a as)

class ADTLens a where

Lens for editable ADTs with support of shared record fields between constructors.

Suppose we have the data type

data X
    = X1 { a :: Int, b :: Bool }
    | X2 { a :: Int, c :: Char }

We can build an editor which can switch between two editor for the constructors. If the field a is edited in one editor, it will be updated in the other.

Associated Types

type ADTEls a :: List *

ADTEls a is the list of types of the parts of the ADT.

For example,

ADTEls X = Cons Int (Cons Bool (Cons Char Nil))

Methods

adtLens :: ([(String, [Int])], Elems (ADTEls a), Lens_ (Int, Elems (ADTEls a)) a)

The lens which defines an abstract editor.

The first parameter defines the displayed constructor name and the parts of the constructor for each constructor. Int is an index in the ADTEls list.

For example, in case of X,

fst3 adtLens = [("X1", [0, 1]), ("X2", [0, 2])]

The second parameter is the list of default values for each part.

The third parameter is a lens from the selected constructor index plus the values of the ADT parts to the ADT values.

Instances

ADTLens T

ADTLens instance for T

adtEditor :: (EffRef m, ADTLens a) => Ref m a -> m (Widget m)

A generic ADT editor