Copyright	(c) Sergey Vinokurov 2018
License	Apache-2.0 (see LICENSE)
Maintainer	serg.foo@gmail.com
Safe Haskell	None
Language	Haskell2010

Data.Emacs.Module.Args

Contents

Argument inference

Description

Synopsis

data Nat
- = Z
- | S Nat
type family EmacsArgs (req :: Nat) (opt :: Nat) (rest :: Bool) (a :: Type) = (r :: Type) | r -> req opt rest a where ...
class EmacsInvocation req opt rest where
- supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs req opt rest a -> m b) -> m b
class GetArities (req :: Nat) (opt :: Nat) (rest :: Bool) where
- arities :: Proxy req -> Proxy opt -> Proxy rest -> (CPtrdiff, CPtrdiff)
data R a b = R !a !b
data O a b = O !(Maybe a) !b
newtype Rest a = Rest [a]
data Stop a = Stop

Documentation

data Nat Source #

Type-level Peano numbers.

Indented to be used with DataKinds extension enabled.

Constructors

Z
S Nat

type family EmacsArgs (req :: Nat) (opt :: Nat) (rest :: Bool) (a :: Type) = (r :: Type) | r -> req opt rest a where ... Source #

Specification of the arguments that exposed functions can receive from Emacs.

This type family allows to declaratively specify how many required and optional arguments a function can take and whether it accepts rest arguments. It's a direct translation of argument lists in Emacs lisp, e.g.

(defun foo (x y z &optional w t &rest quux)
  (+ (* x y z) (* (or w 1) (or t 2)) (length quux)))

The function above has 3 required arguments, 2 optional and also has rest arguments. The type family below has two Nats and one Bool to provide that info.

Equations

EmacsArgs ('S n) opt rest a = R a (EmacsArgs n opt rest a)
EmacsArgs 'Z ('S k) rest a = O a (EmacsArgs 'Z k rest a)
EmacsArgs 'Z 'Z 'True a = Rest a
EmacsArgs 'Z 'Z 'False a = Stop a

class EmacsInvocation req opt rest where Source #

Methods

supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs req opt rest a -> m b) -> m b Source #

Instances

Instances details

EmacsInvocation 'Z 'Z 'False Source #
Instance details Defined in Data.Emacs.Module.Args Methods supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs 'Z 'Z 'False a -> m b) -> m b Source #
EmacsInvocation 'Z 'Z 'True Source #
Instance details Defined in Data.Emacs.Module.Args Methods supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs 'Z 'Z 'True a -> m b) -> m b Source #
EmacsInvocation 'Z n rest => EmacsInvocation 'Z ('S n) rest Source #
Instance details Defined in Data.Emacs.Module.Args Methods supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs 'Z ('S n) rest a -> m b) -> m b Source #
EmacsInvocation n opt rest => EmacsInvocation ('S n) opt rest Source #
Instance details Defined in Data.Emacs.Module.Args Methods supplyEmacsArgs :: MonadBase IO m => Int -> Ptr RawValue -> (RawValue -> m a) -> (EmacsArgs ('S n) opt rest a -> m b) -> m b Source #

class GetArities (req :: Nat) (opt :: Nat) (rest :: Bool) where Source #

Helper to retrieve number of arguments a function takes for Emacs.

Methods

arities :: Proxy req -> Proxy opt -> Proxy rest -> (CPtrdiff, CPtrdiff) Source #

Instances

Instances details

NatValue req => GetArities req opt 'True Source #
Instance details Defined in Data.Emacs.Module.Args Methods arities :: Proxy req -> Proxy opt -> Proxy 'True -> (CPtrdiff, CPtrdiff) Source #
(NatValue req, NatValue opt) => GetArities req opt 'False Source #
Instance details Defined in Data.Emacs.Module.Args Methods arities :: Proxy req -> Proxy opt -> Proxy 'False -> (CPtrdiff, CPtrdiff) Source #

Argument inference

data R a b Source #

Required argument of an exported function.

Constructors

R !a !b

data O a b Source #

Optional argument of an exported function.

Constructors

O !(Maybe a) !b

newtype Rest a Source #

All other arguments of an exported function as a list.

Constructors

Rest [a]

data Stop a Source #

End of argument list of an exported funciton.

Constructors

Stop