Copyright	(C) 2015 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	non-portable
Safe Haskell	Unsafe
Language	Haskell2010

Data.Struct

Contents

Nil
Slots and Fields

Description

Synopsis

Documentation

class Struct t where Source

An instance for Struct t is a witness to the machine-level equivalence of t and Object.

Minimal complete definition

Nothing

Methods

struct :: Dict (Coercible (t s) (Object s)) Source

Instances

Struct Object Source
Struct Label Source
Struct (LinkCut a) Source
Struct (Order a) Source

data Object s Source

Instances

Struct Object Source
Eq (Object s) Source

destruct :: Struct t => t s -> SmallMutableArray# s Any Source

construct :: Struct t => SmallMutableArray# s Any -> t s Source

eqStruct :: Struct t => t s -> t s -> Bool Source

alloc :: (PrimMonad m, Struct t) => Int -> m (t (PrimState m)) Source

Allocate a structure made out of n slots. Initialize the structure before proceeding!

Nil

pattern Nil :: () => Struct t => t s Source

Truly imperative.

isNil :: Struct t => t s -> Bool Source

Predicate to check if a struct is Nil.

>>> isNil (Nil :: Object (PrimState IO))
True
>>> o <- alloc 1 :: IO (Object (PrimState IO))
>>> isNil o
False

data NullPointerException Source

Constructors

NullPointerException

Instances

Show NullPointerException Source
Exception NullPointerException Source

Slots and Fields

data Slot x y Source

A Slot is a reference to another unboxed mutable object.

Instances

Precomposable k k (Slot k k) Source

slot Source

Arguments

:: Int	slot
-> Slot s t

The Slot at the given position in a Struct

get :: (PrimMonad m, Struct x, Struct y) => Slot x y -> x (PrimState m) -> m (y (PrimState m)) Source

Get the value from a Slot

set :: (PrimMonad m, Struct x, Struct y) => Slot x y -> x (PrimState m) -> y (PrimState m) -> m () Source

Set the value of a Slot

data Field x a Source

A Field is a reference from a struct to a normal Haskell data type.

Instances

Precomposable k * (Field k) Source

field Source

Arguments

:: Int	slot
-> Field s a

Store the reference to the Haskell data type in a normal field

unboxedField Source

Arguments

:: Prim a
=> Int	slot
-> Int	argument
-> Field s a

Store the reference in the nth slot in the nth argument, treated as a MutableByteArray

getField :: (PrimMonad m, Struct x) => Field x a -> x (PrimState m) -> m a Source

Get the value of a field in a struct

setField :: (PrimMonad m, Struct x) => Field x a -> x (PrimState m) -> a -> m () Source

Set the value of a field in a struct

modifyField :: (Struct x, PrimMonad m) => Field x a -> x (PrimState m) -> (a -> a) -> m () Source

modifyField' :: (Struct x, PrimMonad m) => Field x a -> x (PrimState m) -> (a -> a) -> m () Source

class Precomposable t where Source

We can compose slots to get a nested slot or field accessor

Methods

(#) :: Slot x y -> t y z -> t x z Source

Instances

Precomposable k * (Field k) Source
Precomposable k k (Slot k k) Source