Sound.Hommage.Parameter

Sound.Hommage.Parameter

Contents

Field
Hetero List

Description

This module contains a datatype Field and sone type classes. It is used to construct record-like datatypes.

Synopsis

data Field c a = Field {

getField :: (c -> a)

setField :: ((a -> a) -> c -> c)

}

(<>) :: Field a b -> Field c a -> Field c b

fstField :: Field (a, b) a

sndField :: Field (a, b) b

data UpdateField c

= forall a . (:=) (Field c a) a

| forall a . (:$) (Field c a) (a -> a)

| If (CheckField c) [UpdateField c] [UpdateField c]

data CheckField c

= forall a . (:?) (Field c a) (a -> Bool)

| And [CheckField c]

| Or [CheckField c]

updateField :: UpdateField c -> c -> c

checkField :: CheckField c -> c -> Bool

applyField :: [UpdateField c] -> c -> c

withField :: [UpdateField a] -> (a -> b) -> a -> b

data Group c a = Group {

isGroup :: (c -> Maybe a)

mkGroup :: (a -> c)

}

leftGroup :: Group (Either a b) a

rightGroup :: Group (Either a b) b

(><) :: Group a b -> Group c a -> Group c b

data LM a b m = (:>>) (m a) (b m)

data NilM m = NilM

class PushFields m where

pushFields :: m (Field c) -> m (Field (x, c))

class ToFields a r where

toFields :: a -> r (Field a)

class PushGroups m where

pushGroups :: m (Group c) -> m (Group (Either x c))

class ToGroups a r where

toGroups :: a -> r (Group a)

Documentation

Example:

To create a "record" with the accessors/modificators first you have to define the type of the record, It must be a right-associative list of pairs, just like a LISP list. The rightmost element must be () . The following Example defines a record with information for music generation.

 type DefaultNote = (Int, (Double, (Char, ())))

Then a default value should be defined.

 defaultNote = (0, (1.0, ('a' , ())))
 defaultNote :: DefaultNote

For each "datafield" the Field must be declared.

 pitch :: Field DefaultNote Int 
 volume :: Field DefaultNote Double 
 channel :: Field DefaultNote Char

Creating the fields is done with toField applied to a value of the "record" type.

 pitch :>> volume :>> channel :>> NilM = toFields defaultNote

Is is recommended to declare all types and match all results of toFields incl. the NilM at the end.

NOTE:

 pitch :>> volume :>> channel :>> NilM = toFields (undefined :: DefaultNote)

should work too.

data Field c a

A Field record field is an interface to access a type field which is part of a type record . A Field is used to access and modify subtypes ("datafields") of a record-like datastructure. In this module, a right-associative pair structure is taken as record-type with "datafields" in the fst parts of the pairs.

Constructors

Field

getField :: (c -> a)
setField :: ((a -> a) -> c -> c)

(<>) :: Field a b -> Field c a -> Field c b

fstField :: Field (a, b) a

sndField :: Field (a, b) b

data UpdateField c

Constructors

forall a . (:=) (Field c a) a
forall a . (:$) (Field c a) (a -> a)
If (CheckField c) [UpdateField c] [UpdateField c]

data CheckField c

Constructors

forall a . (:?) (Field c a) (a -> Bool)
And [CheckField c]
Or [CheckField c]

updateField :: UpdateField c -> c -> c

checkField :: CheckField c -> c -> Bool

applyField :: [UpdateField c] -> c -> c

withField :: [UpdateField a] -> (a -> b) -> a -> b

data Group c a

Constructors

Group

isGroup :: (c -> Maybe a)
mkGroup :: (a -> c)

leftGroup :: Group (Either a b) a

rightGroup :: Group (Either a b) b

(><) :: Group a b -> Group c a -> Group c b

data LM a b m

Constructors

(:>>) (m a) (b m)

Instances

(PushFields b) => PushFields (LM a b)

(PushFields b', ToFields b b') => ToFields (a, b) (LM a b')

(PushGroups b) => PushGroups (LM a b)

(ToGroups b b', PushGroups b') => ToGroups (Either a b) (LM a b')

data NilM m

The correct type is: data NilM (m :: * -> *) = NilM . (But Haddock rejects this definition. GHC will need it)

Constructors

NilM

Instances

PushFields NilM

ToFields () NilM

PushGroups NilM

ToGroups () NilM

class PushFields m where

Methods

pushFields :: m (Field c) -> m (Field (x, c))

Instances

PushFields NilM

(PushFields b) => PushFields (LM a b)

class ToFields a r where

Methods

toFields :: a -> r (Field a)

Instances

ToFields () NilM

(PushFields b', ToFields b b') => ToFields (a, b) (LM a b')

class PushGroups m where

Methods

pushGroups :: m (Group c) -> m (Group (Either x c))

Instances

PushGroups NilM

(PushGroups b) => PushGroups (LM a b)

class ToGroups a r where

Methods

toGroups :: a -> r (Group a)

Instances

ToGroups () NilM

(ToGroups b b', PushGroups b') => ToGroups (Either a b) (LM a b')

Produced by Haddock version HADDOCK_VERSION