folly::gen::detail::FoldLeft< Seed, Fold > Class Template Reference

#include <Base-inl.h>

Inheritance diagram for folly::gen::detail::FoldLeft< Seed, Fold >:

Public Member Functions
	FoldLeft ()=default
	FoldLeft (Seed seed, Fold fold)
template<class Source , class Value >
Seed	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::Operator< FoldLeft< Seed, Fold > >
ResultGen	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::FBounded< Self >
const Self &	self () const
Self &	self ()

Private Attributes
Seed	seed_
Fold	fold_

Additional Inherited Members
Protected Member Functions inherited from folly::gen::Operator< FoldLeft< Seed, Fold > >
	Operator ()=default
	Operator (Operator &&) noexcept=default
	Operator (const Operator &)=default
Operator &	operator= (Operator &&) noexcept=default
Operator &	operator= (const Operator &)=default

Detailed Description

template<class Seed, class Fold>
class folly::gen::detail::FoldLeft< Seed, Fold >

FoldLeft - Left-associative functional fold. For producing an aggregate value from a seed and a folder function. Useful for custom aggregators on a sequence.

This type is primarily used through the 'foldl' helper method, like:

double movingAverage = from(values) | foldl(0.0, [](double avg, double sample) { return sample * 0.1 + avg * 0.9; });

Definition at line 2004 of file Base-inl.h.

Constructor & Destructor Documentation

template<class Seed , class Fold >

folly::gen::detail::FoldLeft< Seed, Fold >::FoldLeft ( )

default

template<class Seed , class Fold >

folly::gen::detail::FoldLeft< Seed, Fold >::FoldLeft ( Seed  seed, Fold  fold  )

inline

Definition at line 2010 of file Base-inl.h.

      : seed_(std::move(seed)), fold_(std::move(fold)) {}

Member Function Documentation

template<class Seed , class Fold >

template<class Source , class Value >

Seed folly::gen::detail::FoldLeft< Seed, Fold >::compose ( const GenImpl< Value, Source > &  source ) const

inline

Definition at line 2014 of file Base-inl.h.

References folly::gen::move, v, and testing::Value().

                                                           {
    static_assert(!Source::infinite, "Cannot foldl infinite source");
    Seed accum = seed_;
    source | [&](Value v) {
      accum = fold_(std::move(accum), std::forward<Value>(v));
    };
    return accum;
  }

Member Data Documentation

template<class Seed , class Fold >

Fold folly::gen::detail::FoldLeft< Seed, Fold >::fold_

private

Definition at line 2006 of file Base-inl.h.

template<class Seed , class Fold >

Seed folly::gen::detail::FoldLeft< Seed, Fold >::seed_

private

Definition at line 2005 of file Base-inl.h.

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The documentation for this class was generated from the following file:

• proxygen/folly/folly/gen/Base-inl.h