Copyright	(c) Francesco Gazzetta 2017
License	BSD3 (see the file LICENSE)
Maintainer	francygazz@gmail.org
Stability	stable
Portability	portable
Safe Haskell	Safe
Language	Haskell2010

Data.Accumulator

Description

Accumulators, primarily useful for Polyvariadic

Synopsis

class Accumulator acc x where
- accumulate :: x -> acc -> acc
singleton :: (Accumulator acc x, Monoid acc) => x -> acc
accumulateMany :: (Foldable f, Accumulator acc x) => f x -> acc -> acc
newtype AccumulatorSemigroup a = AccumulatorSemigroup {
- getAccumulatorSemigroup :: a
}

Documentation

class Accumulator acc x where Source #

An 'Accumulator c i' supports accumulation of elements of type i in it. This is different from Semigroup or Monoid, where <> acts between two values with the same type.

Methods

accumulate Source #

Arguments

:: x
-> acc
-> acc	Accumulate a value

Instances

Accumulator [a] a Source #
Instance details Defined in Data.Accumulator Methods accumulate :: a -> [a] -> [a] Source #
Ord a => Accumulator (Set a) a Source #
Instance details Defined in Data.Accumulator Methods accumulate :: a -> Set a -> Set a Source #
Semigroup m => Accumulator (AccumulatorSemigroup m) (AccumulatorSemigroup m) Source #
Instance details Defined in Data.Accumulator Methods accumulate :: AccumulatorSemigroup m -> AccumulatorSemigroup m -> AccumulatorSemigroup m Source #

singleton :: (Accumulator acc x, Monoid acc) => x -> acc Source #

Accumulate a single value in a Monoid

accumulateMany :: (Foldable f, Accumulator acc x) => f x -> acc -> acc Source #

Strictly accumulate multiple values from a Foldable, from left to right

newtype AccumulatorSemigroup a Source #

Lift a Semigroup into an Accumulator. This is a newtype because (<>) isn't always the ideal way of accumulating

Constructors

AccumulatorSemigroup
Fields getAccumulatorSemigroup :: a

Instances

Semigroup m => Semigroup (AccumulatorSemigroup m) Source #
Instance details Defined in Data.Accumulator Methods (<>) :: AccumulatorSemigroup m -> AccumulatorSemigroup m -> AccumulatorSemigroup m # sconcat :: NonEmpty (AccumulatorSemigroup m) -> AccumulatorSemigroup m # stimes :: Integral b => b -> AccumulatorSemigroup m -> AccumulatorSemigroup m #
Semigroup m => Accumulator (AccumulatorSemigroup m) (AccumulatorSemigroup m) Source #
Instance details Defined in Data.Accumulator Methods accumulate :: AccumulatorSemigroup m -> AccumulatorSemigroup m -> AccumulatorSemigroup m Source #