| License | MIT |
|---|---|
| Maintainer | mail@doisinkidney.com |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Semiring
Description
- class Semiring a where
- class Semiring a => StarSemiring a where
- class HasPositiveInfinity a where
- class HasNegativeInfinity a where
- class Semiring a => DetectableZero a where
- newtype Add a = Add {
- getAdd :: a
- newtype Mul a = Mul {
- getMul :: a
- add :: (Foldable f, Semiring a) => f a -> a
- mul :: (Foldable f, Semiring a) => f a -> a
- newtype Max a = Max {
- getMax :: a
- newtype Min a = Min {
- getMin :: a
Semiring classes
class Semiring a where Source #
A Semiring is like the
the combination of two Monoids. The first
is called <+>; it has the identity element zero, and it is
commutative. The second is called <.>; it has identity element one,
and it must distribute over <+>.
Laws
Normal Monoid laws
(a<+>b)<+>c = a<+>(b<+>c)zero<+>a = a<+>zero= a (a<.>b)<.>c = a<.>(b<.>c)one<.>a = a<.>one= a
Commutativity of <+>
a<+>b = b<+>a
Distribution of <.> over <+>
a<.>(b<+>c) = (a<.>b)<+>(a<.>c) (a<+>b)<.>c = (a<.>c)<+>(b<.>c)
Annihilation
zero<.>a = a<.>zero=zero
An ordered semiring follows the laws:
x<=y => x<+>z<=y<+>z x<=y => x<+>z<=y<+>zzero<=z&&x<=y => x<.>z<=y<.>z&&z<.>x<=z<.>y
Methods
The identity of <+>.
The identity of <.>.
(<.>) :: a -> a -> a infixl 7 Source #
An associative binary operation, which distributes over <+>.
(<+>) :: a -> a -> a infixl 6 Source #
An associative, commutative binary operation.
The identity of <+>.
The identity of <.>.
(<+>) :: Num a => a -> a -> a infixl 6 Source #
An associative, commutative binary operation.
(<.>) :: Num a => a -> a -> a infixl 7 Source #
An associative binary operation, which distributes over <+>.
Instances
class Semiring a => StarSemiring a where Source #
A Star semiring
adds one operation, star to a Semiring, such that it follows the
law:
starx =one<+>x<.>starx =one<+>starx<.>x
For the semiring of types, this is equivalent to a list. When looking
at the Applicative and Alternative classes as
(near-) semirings, this is equivalent to the
many operation.
Another operation, plus, can be defined in relation to star:
plusx = x<.>starx
This should be recognizable as a non-empty list on types, or the
some operation in
Alternative.
Instances
Helper classes
class HasPositiveInfinity a where Source #
A class for semirings with a concept of "infinity". It's important that
this isn't regarded as the same as "bounded":
x should probably equal <+> positiveInfinitypositiveInfinity.
Methods
positiveInfinity :: a Source #
A positive infinite value
positiveInfinity :: RealFloat a => a Source #
A positive infinite value
isPositiveInfinity :: a -> Bool Source #
Test if a value is positive infinity.
isPositiveInfinity :: RealFloat a => a -> Bool Source #
Test if a value is positive infinity.
class HasNegativeInfinity a where Source #
A class for semirings with a concept of "negative infinity". It's important
that this isn't regarded as the same as "bounded":
x should probably equal <+> negativeInfinitynegativeInfinity.
Methods
negativeInfinity :: a Source #
A negative infinite value
negativeInfinity :: RealFloat a => a Source #
A negative infinite value
isNegativeInfinity :: a -> Bool Source #
Test if a value is negative infinity.
isNegativeInfinity :: RealFloat a => a -> Bool Source #
Test if a value is negative infinity.
class Semiring a => DetectableZero a where Source #
Useful for operations where zeroes may need to be discarded: for instance in sparse matrix calculations.
Methods
Instances
Monoidal wrappers
Instances
| Functor Add Source # | |
| Foldable Add Source # | |
| Traversable Add Source # | |
| Generic1 Add Source # | |
| Bounded a => Bounded (Add a) Source # | |
| Enum a => Enum (Add a) Source # | |
| Eq a => Eq (Add a) Source # | |
| Fractional a => Fractional (Add a) Source # | |
| Num a => Num (Add a) Source # | |
| Ord a => Ord (Add a) Source # | |
| Read a => Read (Add a) Source # | |
| Real a => Real (Add a) Source # | |
| RealFrac a => RealFrac (Add a) Source # | |
| Show a => Show (Add a) Source # | |
| Generic (Add a) Source # | |
| Semiring a => Semigroup (Add a) Source # | |
| Semiring a => Monoid (Add a) Source # | |
| Storable a => Storable (Add a) Source # | |
| DetectableZero a => DetectableZero (Add a) Source # | |
| StarSemiring a => StarSemiring (Add a) Source # | |
| Semiring a => Semiring (Add a) Source # | |
| type Rep1 Add Source # | |
| type Rep (Add a) Source # | |
Instances
| Functor Mul Source # | |
| Foldable Mul Source # | |
| Traversable Mul Source # | |
| Generic1 Mul Source # | |
| Bounded a => Bounded (Mul a) Source # | |
| Enum a => Enum (Mul a) Source # | |
| Eq a => Eq (Mul a) Source # | |
| Fractional a => Fractional (Mul a) Source # | |
| Num a => Num (Mul a) Source # | |
| Ord a => Ord (Mul a) Source # | |
| Read a => Read (Mul a) Source # | |
| Real a => Real (Mul a) Source # | |
| RealFrac a => RealFrac (Mul a) Source # | |
| Show a => Show (Mul a) Source # | |
| Generic (Mul a) Source # | |
| Semiring a => Semigroup (Mul a) Source # | |
| Semiring a => Monoid (Mul a) Source # | |
| Storable a => Storable (Mul a) Source # | |
| DetectableZero a => DetectableZero (Mul a) Source # | |
| StarSemiring a => StarSemiring (Mul a) Source # | |
| Semiring a => Semiring (Mul a) Source # | |
| type Rep1 Mul Source # | |
| type Rep (Mul a) Source # | |
Ordering wrappers
The "Arctic" or max-plus semiring. It is a semiring where:
<+>=maxzero= -∞<.>=<+>one=zero
Note that we can't use Max from Semigroup
because annihilation needs to hold:
-∞<+>x = x<+>-∞ = -∞
Taking -∞ to be minBound would break the above law. Using
negativeInfinity to represent it follows the law.
Instances
| Functor Max Source # | |
| Foldable Max Source # | |
| Traversable Max Source # | |
| Generic1 Max Source # | |
| Bounded a => Bounded (Max a) Source # | |
| Enum a => Enum (Max a) Source # | |
| Eq a => Eq (Max a) Source # | |
| Fractional a => Fractional (Max a) Source # | |
| Num a => Num (Max a) Source # | |
| Ord a => Ord (Max a) Source # | |
| Read a => Read (Max a) Source # | |
| Real a => Real (Max a) Source # | |
| RealFrac a => RealFrac (Max a) Source # | |
| Show a => Show (Max a) Source # | |
| Generic (Max a) Source # | |
| Ord a => Semigroup (Max a) Source # | |
| (Ord a, HasNegativeInfinity a) => Monoid (Max a) Source # |
|
| Storable a => Storable (Max a) Source # | |
| (Semiring a, Ord a, HasNegativeInfinity a) => DetectableZero (Max a) Source # | |
| (Semiring a, Ord a, HasPositiveInfinity a, HasNegativeInfinity a) => StarSemiring (Max a) Source # | |
| (Semiring a, Ord a, HasNegativeInfinity a) => Semiring (Max a) Source # | |
| type Rep1 Max Source # | |
| type Rep (Max a) Source # | |
The "Tropical" or min-plus semiring. It is a semiring where:
<+>=minzero= ∞<.>=<+>one=zero
Note that we can't use Min from Semigroup
because annihilation needs to hold:
∞<+>x = x<+>∞ = ∞
Taking ∞ to be maxBound would break the above law. Using positiveInfinity
to represent it follows the law.
Instances
| Functor Min Source # | |
| Foldable Min Source # | |
| Traversable Min Source # | |
| Generic1 Min Source # | |
| Bounded a => Bounded (Min a) Source # | |
| Enum a => Enum (Min a) Source # | |
| Eq a => Eq (Min a) Source # | |
| Fractional a => Fractional (Min a) Source # | |
| Num a => Num (Min a) Source # | |
| Ord a => Ord (Min a) Source # | |
| Read a => Read (Min a) Source # | |
| Real a => Real (Min a) Source # | |
| RealFrac a => RealFrac (Min a) Source # | |
| Show a => Show (Min a) Source # | |
| Generic (Min a) Source # | |
| Ord a => Semigroup (Min a) Source # | |
| (Ord a, HasPositiveInfinity a) => Monoid (Min a) Source # |
|
| Storable a => Storable (Min a) Source # | |
| (Semiring a, Ord a, HasPositiveInfinity a) => DetectableZero (Min a) Source # | |
| (Semiring a, Ord a, HasPositiveInfinity a, HasNegativeInfinity a) => StarSemiring (Min a) Source # | |
| (Semiring a, Ord a, HasPositiveInfinity a) => Semiring (Min a) Source # | |
| type Rep1 Min Source # | |
| type Rep (Min a) Source # | |