Copyright	(c) Ross Paterson 2011
License	BSD-style (see the file LICENSE)
Maintainer	[email protected]
Stability	provisional
Portability	portable
Safe Haskell	None
Language	Haskell2010

Data.YAP.Quantity

Description

An example instance of the algebraic classes: numeric quantities with unit types. You can only compare and add quantities that use the same units.

Synopsis

newtype Quantity u a = Quantity a
scale :: Semiring a => a -> Quantity u a -> Quantity u a

Documentation

newtype Quantity u a Source #

Quantities of a numeric type a, in units encoded by the phantom type parameter u. For example, types for counting apples and oranges can be defined as:

data Apple
data Orange
type Apples = Quantity Apple Int
type Oranges = Quantity Orange Int

You can't compare Apples with Oranges (or add them). You can add Apples to Apples, but not multiply them.

A full dimensional system keeping track of units while modelling multiplication and division will require type-level functions.

Constructors

Quantity a

Instances

Instances details

Read a => Read (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods readsPrec :: Int -> ReadS (Quantity u a) # readList :: ReadS [Quantity u a] # readPrec :: ReadPrec (Quantity u a) # readListPrec :: ReadPrec [Quantity u a] #
Show a => Show (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods showsPrec :: Int -> Quantity u a -> ShowS # show :: Quantity u a -> String # showList :: [Quantity u a] -> ShowS #
Eq a => Eq (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods (==) :: Quantity u a -> Quantity u a -> Bool # (/=) :: Quantity u a -> Quantity u a -> Bool #
Ord a => Ord (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods compare :: Quantity u a -> Quantity u a -> Ordering # (<) :: Quantity u a -> Quantity u a -> Bool # (<=) :: Quantity u a -> Quantity u a -> Bool # (>) :: Quantity u a -> Quantity u a -> Bool # (>=) :: Quantity u a -> Quantity u a -> Bool # max :: Quantity u a -> Quantity u a -> Quantity u a # min :: Quantity u a -> Quantity u a -> Quantity u a #
AbelianGroup a => AbelianGroup (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods (-) :: Quantity u a -> Quantity u a -> Quantity u a # negate :: Quantity u a -> Quantity u a # gtimes :: (AbelianGroup b, ToInteger b) => b -> Quantity u a -> Quantity u a #
AdditiveMonoid a => AdditiveMonoid (Quantity u a) Source #
Instance details Defined in Data.YAP.Quantity Methods (+) :: Quantity u a -> Quantity u a -> Quantity u a # zero :: Quantity u a # atimes :: ToInteger b => b -> Quantity u a -> Quantity u a #

scale :: Semiring a => a -> Quantity u a -> Quantity u a Source #

Multiply by a scalar