trait Semigroup[F] extends AnyRef
An associative binary operation, circumscribed by type and the semigroup laws. Unlike scalaz.Monoid, there is not necessarily a zero.
- Self Type
- Semigroup[F]
- Source
- Semigroup.scala
- See also
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- Semigroup
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Type Members
-
trait
SemigroupApply extends Apply[[α]F]
- Attributes
- protected[this]
-
trait
SemigroupCompose extends Compose[[α, β]F]
- Attributes
- protected[this]
-
trait
SemigroupLaw extends AnyRef
A semigroup in type F must satisfy two laws:
A semigroup in type F must satisfy two laws:
- closure:
∀ a, b in F, append(a, b)
is also inF
. This is enforced by the type system. - associativity:
∀ a, b, c
inF
, the equationappend(append(a, b), c) = append(a, append(b , c))
holds.
- closure:
Abstract Value Members
-
abstract
def
append(f1: F, f2: ⇒ F): F
The binary operation to combine
f1
andf2
.The binary operation to combine
f1
andf2
.Implementations should not evaluate the by-name parameter
f2
if result can be determined byf1
.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
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final
def
##(): Int
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-
final
def
==(arg0: Any): Boolean
- Definition Classes
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-
final
def
apply: Apply[[α]F]
An scalaz.Apply, that implements
ap
withappend
.An scalaz.Apply, that implements
ap
withappend
. Note that the type parameterα
inApply[λ[α => F]]
is discarded; it is a phantom type. As such, the functor cannot support scalaz.Bind. -
final
def
asInstanceOf[T0]: T0
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-
def
clone(): AnyRef
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- protected[lang]
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final
def
compose: Compose[[α, β]F]
Every
Semigroup
gives rise to a scalaz.Compose, for which the type parameters are phantoms.Every
Semigroup
gives rise to a scalaz.Compose, for which the type parameters are phantoms.- Note
compose.semigroup
=this
-
final
def
eq(arg0: AnyRef): Boolean
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def
equals(arg0: Any): Boolean
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-
def
finalize(): Unit
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- protected[lang]
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- @throws( classOf[java.lang.Throwable] )
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final
def
getClass(): Class[_]
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def
hashCode(): Int
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final
def
isInstanceOf[T0]: Boolean
- Definition Classes
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-
def
multiply1(value: F, n: Int): F
For
n = 0
,value
Forn = 1
,append(value, value)
Forn = 2
,append(append(value, value), value)
For
n = 0
,value
Forn = 1
,append(value, value)
Forn = 2
,append(append(value, value), value)
The default definition uses peasant multiplication, exploiting associativity to only require
O(log n)
uses of append -
final
def
ne(arg0: AnyRef): Boolean
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final
def
notify(): Unit
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- @native()
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final
def
notifyAll(): Unit
- Definition Classes
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- @native()
- def semigroupLaw: SemigroupLaw
- val semigroupSyntax: SemigroupSyntax[F]
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
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def
toString(): String
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final
def
wait(): Unit
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final
def
wait(arg0: Long, arg1: Int): Unit
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final
def
wait(arg0: Long): Unit
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