Copyright	(c) George Ungureanu 2015-2016
License	BSD-style (see the file LICENSE)
Maintainer	ugeorge@kth.se
Stability	experimental
Portability	portable
Safe Haskell	Safe
Language	Haskell2010

ForSyDe.Atom.ExB.Absent

Description

This module implements the constructors and assocuated utilities of a type which extends the behavior of a function to express "absent events" (see [Halbwachs91]).

The AbstExt type can be used directly with the atom patterns defined in ForSyDe.Atom.ExB, and no helpers or utilities are needed. Example usage:

>>> res21 (+) (Prst 1) (Prst 2)
3
>>> res21 (+) Abst     Abst
⟂
>>> filter Abst         (Prst 1)
⟂
>>> filter (Prst False) (Prst 1)
⟂
>>> filter (Prst True)  (Prst 1)
1
>>> filter' False 1 :: AbstExt Int
⟂
>>> filter' True  1 :: AbstExt Int
1
>>> degen 0 (Prst 1)
1
>>> degen 0 Abst
0
>>> ignore11 (+) 1 (Prst 1)
2
>>> ignore11 (+) 1 Abst
1

Incorrect usage (not covered by doctest):

λ> res21 (+) (Prst 1) Abst 
*** Exception: [ExB.Absent] Illegal occurrence of an absent and present event

Synopsis

data AbstExt a
- = Abst
- | Prst a
module ForSyDe.Atom.ExB

Documentation

data AbstExt a Source #

The AbstExt type extends the base type with the '(bot)' symbol denoting the absence of a value/event (see [Halbwachs91]).

Constructors

Abst	$\bot$ denotes the absence of a value
Prst a	$\top$ a present event with a value

Instances

Instances details

Functor AbstExt Source #	`Functor` instance. Bypasses the special values and maps a function to the wrapped value.
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods fmap :: (a -> b) -> AbstExt a -> AbstExt b # (<$) :: a -> AbstExt b -> AbstExt a #
Applicative AbstExt Source #	`Applicative` instance, defines a resolution. Check source code for the lifting rules.
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods pure :: a -> AbstExt a # (<>) :: AbstExt (a -> b) -> AbstExt a -> AbstExt b # liftA2 :: (a -> b -> c) -> AbstExt a -> AbstExt b -> AbstExt c # (>) :: AbstExt a -> AbstExt b -> AbstExt b # (<*) :: AbstExt a -> AbstExt b -> AbstExt a #
ExB AbstExt Source #	Implements the absent semantics of the extended behavior atoms.
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods extend :: a -> AbstExt a Source # (/.\) :: (a -> a') -> AbstExt a -> AbstExt a' Source # (/*\) :: AbstExt (a -> a') -> AbstExt a -> AbstExt a' Source # (/&\) :: AbstExt Bool -> AbstExt a -> AbstExt a Source # (/!\) :: a -> AbstExt a -> a Source #
Eq a => Eq (AbstExt a) Source #
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods (==) :: AbstExt a -> AbstExt a -> Bool # (/=) :: AbstExt a -> AbstExt a -> Bool #
Read a => Read (AbstExt a) Source #	Reads the '_' character to an `Abst` and a normal value to `Prst`-wrapped one.
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods readsPrec :: Int -> ReadS (AbstExt a) # readList :: ReadS [AbstExt a] # readPrec :: ReadPrec (AbstExt a) # readListPrec :: ReadPrec [AbstExt a] #
Show a => Show (AbstExt a) Source #	Shows `Abst` as $\bot$, while a present event is represented with its value.
Instance details Defined in ForSyDe.Atom.ExB.Absent Methods showsPrec :: Int -> AbstExt a -> ShowS # show :: AbstExt a -> String # showList :: [AbstExt a] -> ShowS #
(Show a, Plottable a) => Plottable (AbstExt a) Source #	Absent-extended plottable types
Instance details Defined in ForSyDe.Atom.Utility.Plot Methods toCoord :: AbstExt a -> String Source #

Module ForSyDe.Atom.ExB is re-exported for convenience, to access the atom patterns more easily.

module ForSyDe.Atom.ExB

Abst	\(\bot\) denotes the absence of a value
Prst a	\(\top\) a present event with a value