loop

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 Go to latest Published: May 26, 2023 License: MIT Imports: 12 Imported by: 3

Documentation

Overview

Package loop provides helpers for loop operation and iterator implementations

Index

Constants

This section is empty.

Variables

View Source 
var ErrBreak = c.ErrBreak

ErrBreak is the 'break' statement of the For, Track methods

Functions

func Append 

func Append[T any, TS ~[]T](next func() (T, bool), out TS) TS

Append collects the elements retrieved by the 'next' function into the specified 'out' slice

func Contains 

func Contains[T comparable](next func() (T, bool), example T) bool

Contains finds the first element that equal to the example and returns true

func Conv added in v0.0.8 

func Conv[From, To any](next func() (From, bool), converter func(From) (To, error)) loop.ConvertIter[From, To]

Conv instantiates an iterator that converts elements with a converter and returns them.

func ConvAndReduce added in v0.0.8 

func ConvAndReduce[From, To any](next func() (From, bool), converter func(From) (To, error), merger func(To, To) To) (out To, err error)

ConvAndReduce converts each elements and merges them into one

func ConvCheck added in v0.0.8 

func ConvCheck[From, To any](next func() (From, bool), converter func(from From) (To, bool, error)) loop.ConvertCheckIter[From, To]

ConvCheck is similar to ConvertFilt, but it checks and transforms elements together

func ConvertAndReduce added in v0.0.8 

func ConvertAndReduce[From, To any](next func() (From, bool), converter func(From) To, merger func(To, To) To) (out To)

ConvertAndReduce converts each elements and merges them into one

func Filt added in v0.0.8 

func Filt[T any](next func() (T, bool), filter func(T) (bool, error)) loop.FiltIter[T]

Filt creates an iterator that checks elements by the 'filter' function and returns successful ones.

func FiltAndConv added in v0.0.9 

func FiltAndConv[From, To any](next func() (From, bool), filter func(From) (bool, error), converter func(From) (To, error)) loop.ConvFiltIter[From, To]

FiltAndConv returns a stream that filters source elements and converts them

func FiltAndFlat added in v0.0.9 

func FiltAndFlat[From, To any](next func() (From, bool), filter func(From) (bool, error), flattener func(From) ([]To, error)) loop.FlattFiltIter[From, To]

FiltAndFlat filters source elements and extracts slices of 'To' by the 'flattener' function

func FiltFlattFilt added in v0.0.9 

func FiltFlattFilt[From, To any](next func() (From, bool), filterFrom func(From) (bool, error), flattener func(From) ([]To, error), filterTo func(To) (bool, error)) loop.FlattFiltIter[From, To]

FiltFlattFilt filters source elements, extracts slices of 'To' by the 'flattener' function and filters extracted elements

func First 

func First[T any](next func() (T, bool), predicate func(T) bool) (v T, ok bool)

First returns the first element that satisfies the condition of the 'predicate' function

func FlatAndFilt added in v0.0.9 

func FlatAndFilt[From, To any](next func() (From, bool, error), flattener func(From) ([]To, error), filterTo func(To) (bool, error)) loop.FlattFiltIter[From, To]

FlatAndFilt extracts slices of 'To' by the 'flattener' function and filters extracted elements

func Flatt 

func Flatt[From, To any](next func() (From, bool), flattener func(From) ([]To, error)) loop.FlatIter[From, To]

Flatt instantiates an iterator that extracts slices of 'To' by a flattener from elements of 'From' and flattens as one iterable collection of 'To' elements.

func FlattKeys 

func FlattKeys[T, K, V any](next func() (T, bool), keysExtractor func(T) ([]K, error), valExtractor func(T) (V, error)) *loop.MultipleKeyValuer[T, K, V]

FlattKeys transforms iterable elements to key/value iterator based on applying key, value extractor to the elements

func FlattValues 

func FlattValues[T, K, V any](next func() (T, bool), keyExtractor func(T) (K, error), valsExtractor func(T) ([]V, error)) *loop.MultipleKeyValuer[T, K, V]

FlattValues transforms iterable elements to key/value iterator based on applying key, value extractor to the elements

func For 

func For[T any](next func() (T, bool), walker func(T) error) error

For applies the 'walker' function for the elements retrieved by the 'next' function. Return the c.ErrBreak to stop

func ForEach 

func ForEach[T any](next func() (T, bool), walker func(T))

ForEach applies the 'walker' function to the elements retrieved by the 'next' function

func ForEachFiltered 

func ForEachFiltered[T any](next func() (T, bool), predicate func(T) bool, walker func(T))

ForEachFiltered applies the 'walker' function to the elements retrieved by the 'next' function that satisfy the 'predicate' function condition

func Group 

func Group[T any, K comparable, V any](next func() (T, bool), keyExtractor func(T) K, valExtractor func(T) V) map[K][]V

Group converts elements retrieved by the 'next' function into a map, extracting a key for each element applying the converter 'keyExtractor'. The keyExtractor converts an element to a key. The valExtractor converts an element to an value.

func GroupByMultiple 

func GroupByMultiple[T any, K comparable, V any](next func() (T, bool), keysExtractor func(T) []K, valsExtractor func(T) []V) map[K][]V

GroupByMultiple converts elements retrieved by the 'next' function into a map, extracting multiple keys, values per each element applying the 'keysExtractor' and 'valsExtractor' functions. The keysExtractor retrieves one or more keys per element. The valsExtractor retrieves one or more values per element.

func GroupByMultipleKeys 

func GroupByMultipleKeys[T any, K comparable, V any](next func() (T, bool), keysExtractor func(T) []K, valExtractor func(T) V) map[K][]V

GroupByMultipleKeys converts elements retrieved by the 'next' function into a map, extracting multiple keys, one value per each element applying the 'keysExtractor' and 'valExtractor' functions. The keysExtractor retrieves one or more keys per element. The valExtractor converts an element to a value.

func GroupByMultipleValues 

func GroupByMultipleValues[T any, K comparable, V any](next func() (T, bool), keyExtractor func(T) K, valsExtractor func(T) []V) map[K][]V

GroupByMultipleValues converts elements retrieved by the 'next' function into a map, extracting one key, multiple values per each element applying the 'keyExtractor' and 'valsExtractor' functions. The keyExtractor converts an element to a key. The valsExtractor retrieves one or more values per element.

func HasAny 

func HasAny[T any](next func() (T, bool), predicate func(T) bool) bool

HasAny finds the first element that satisfies the 'predicate' function condition and returns true if successful

func New 

func New[S, T any](source S, hasNext func(S) bool, getNext func(S) T) func() (T, bool)

New makes a loop from an abstract source

func Of 

func Of[T any](elements ...T) func() (e T, ok bool)

Of wrap the elements by loop function

func OfIndexed added in v0.0.8 

func OfIndexed[T any](len int, next func(int) T) func() (T, bool)

OfIndexed builds a loop by extracting elements from an indexed soruce. the len is length ot the source. the getAt retrieves an element by its index from the source.

func Range added in v0.0.8 

func Range[T constraints.Integer](from T, toExclusive T) func() (T, bool)

Range creates a loop that generates integers in the range defined by from and to exclusive

func RangeClosed added in v0.0.8 

func RangeClosed[T constraints.Integer](from T, toInclusive T) func() (T, bool)

RangeClosed creates a loop that generates integers in the range defined by from and to inclusive

func Reduce 

func Reduce[T any](next func() (T, bool), merger func(T, T) T) (result T)

Reduce reduces the elements retrieved by the 'next' function into an one using the 'merger' function

func Slice 

func Slice[T any](next func() (T, bool)) []T

Slice collects the elements retrieved by the 'next' function into a new slice

func SliceCap 

func SliceCap[T any](next func() (T, bool), cap int) (out []T)

SliceCap collects the elements retrieved by the 'next' function into a new slice with predefined capacity

func Sum 

func Sum[T c.Summable](next func() (T, bool)) T

Sum returns the sum of all elements

func ToMapResolv 

func ToMapResolv[T any, K comparable, V, VR any](next func() (T, bool), keyExtractor func(T) K, valExtractor func(T) V, resolver func(bool, K, VR, V) VR) map[K]VR

ToMapResolv collects key\value elements to a map by iterating over the elements with resolving of duplicated key values

func Track 

func Track[I, T any](next func() (I, T, bool), tracker func(I, T) error) error

Track applies the 'tracker' function to position/element pairs retrieved by the 'next' function. Return the c.ErrBreak to stop tracking..

func TrackEach 

func TrackEach[I, T any](next func() (I, T, bool), tracker func(I, T))

TrackEach applies the 'tracker' function to position/element pairs retrieved by the 'next' function

Types

type ConvertCheckIter 

type ConvertCheckIter[From, To any] struct {
	// contains filtered or unexported fields
}

ConvertCheckIter converts and filters elements at the same time

func ConvertCheck 

func ConvertCheck[From, To any](next func() (From, bool), converter func(from From) (To, bool)) ConvertCheckIter[From, To]

ConvertCheck is similar to ConvertFilt, but it checks and transforms elements together

func GetValues 

func GetValues[T any](next func() (*T, bool)) ConvertCheckIter[*T, T]

GetValues creates an iterator that transform only not nil pointers to the values referenced referenced by those pointers. Nil pointers are ignored.

func (ConvertCheckIter[From, To]) Next 

func (c ConvertCheckIter[From, To]) Next() (t To, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type ConvertFiltIter added in v0.0.9 

type ConvertFiltIter[From, To any] struct {
	// contains filtered or unexported fields
}

ConvertFiltIter iterator implementation that retrieves an element by the 'next' function, converts by the 'converter' and addition checks by the 'filter'. If the filter returns true then the converted element is returned as next.

func ConvertAndFilter 

func ConvertAndFilter[From, To any](next func() (From, bool), converter func(From) To, filter func(To) bool) ConvertFiltIter[From, To]

ConvertAndFilter additionally filters 'To' elements

func FilterAndConvert 

func FilterAndConvert[From, To any](next func() (From, bool), filter func(From) bool, converter func(From) To) ConvertFiltIter[From, To]

FilterAndConvert returns a stream that filters source elements and converts them

func FilterConvertFilter 

func FilterConvertFilter[From, To any](next func() (From, bool), filter func(From) bool, converter func(From) To, filterTo func(To) bool) ConvertFiltIter[From, To]

FilterConvertFilter filters source, converts, and filters converted elements

func (ConvertFiltIter[From, To]) For added in v0.0.9 

func (c ConvertFiltIter[From, To]) For(walker func(element To) error) error

For takes elements retrieved by the iterator. Can be interrupt by returning ErrBreak

func (ConvertFiltIter[From, To]) ForEach added in v0.0.9 

func (c ConvertFiltIter[From, To]) ForEach(walker func(element To))

ForEach FlatIter all elements retrieved by the iterator

func (ConvertFiltIter[From, To]) Next added in v0.0.9 

func (c ConvertFiltIter[From, To]) Next() (t To, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type ConvertIter 

type ConvertIter[From, To any] struct {
	// contains filtered or unexported fields
}

ConvertIter iterator implementation that retrieves an element by the 'next' function and converts by the 'converter'

func Convert 

func Convert[From, To any](next func() (From, bool), converter func(From) To) ConvertIter[From, To]

Convert instantiates an iterator that converts elements with a converter and returns them.

func ToValues 

func ToValues[T any](next func() (*T, bool)) ConvertIter[*T, T]

ToValues creates an iterator that transform pointers to the values referenced referenced by those pointers. Nil pointers are transformet to zero values.

func (ConvertIter[From, To]) For 

func (c ConvertIter[From, To]) For(walker func(element To) error) error

For takes elements retrieved by the iterator. Can be interrupt by returning ErrBreak

func (ConvertIter[From, To]) ForEach 

func (c ConvertIter[From, To]) ForEach(walker func(element To))

ForEach FlatIter all elements retrieved by the iterator

func (ConvertIter[From, To]) Next 

func (c ConvertIter[From, To]) Next() (t To, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type FiltIter added in v0.0.9 

type FiltIter[T any] struct {
	// contains filtered or unexported fields
}

FiltIter is the Iterator wrapper that provides filtering of elements by a Predicate.

func Filter 

func Filter[T any](next func() (T, bool), filter func(T) bool) FiltIter[T]

Filter creates an iterator that checks elements by the 'filter' function and returns successful ones.

func NotNil 

func NotNil[T any](next func() (*T, bool)) FiltIter[*T]

NotNil creates an iterator that filters nullable elements

func (FiltIter[T]) For added in v0.0.9 

func (f FiltIter[T]) For(walker func(element T) error) error

For takes elements retrieved by the iterator. Can be interrupt by returning ErrBreak

func (FiltIter[T]) ForEach added in v0.0.9 

func (f FiltIter[T]) ForEach(walker func(element T))

ForEach FlatIter all elements retrieved by the iterator

func (FiltIter[T]) Next added in v0.0.9 

func (f FiltIter[T]) Next() (element T, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type FlatFilterIter added in v0.0.9 

type FlatFilterIter[From, To any] struct {
	// contains filtered or unexported fields
}

FlatFilterIter is the Iterator wrapper that converts an element to a slice with addition filtering of the element by a Predicate and iterates over the slice.

func FilterAndFlat added in v0.0.9 

func FilterAndFlat[From, To any](next func() (From, bool), filter func(From) bool, flattener func(From) []To) FlatFilterIter[From, To]

FilterAndFlat filters source elements and extracts slices of 'To' by the 'flattener' function

func FilterFlatFilter added in v0.0.9 

func FilterFlatFilter[From, To any](next func() (From, bool), filterFrom func(From) bool, flattener func(From) []To, filterTo func(To) bool) FlatFilterIter[From, To]

FilterFlatFilter filters source elements, extracts slices of 'To' by the 'flattener' function and filters extracted elements

func FlattAndFilter 

func FlattAndFilter[From, To any](next func() (From, bool), flattener func(From) []To, filterTo func(To) bool) FlatFilterIter[From, To]

FlattAndFilter extracts slices of 'To' by the 'flattener' function and filters extracted elements

func (*FlatFilterIter[From, To]) For added in v0.0.9 

func (i *FlatFilterIter[From, To]) For(walker func(element To) error) error

For takes elements retrieved by the iterator. Can be interrupt by returning ErrBreak

func (*FlatFilterIter[From, To]) ForEach added in v0.0.9 

func (i *FlatFilterIter[From, To]) ForEach(walker func(element To))

ForEach FlatIter all elements retrieved by the iterator

func (*FlatFilterIter[From, To]) Next added in v0.0.9 

func (i *FlatFilterIter[From, To]) Next() (t To, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type FlatIter 

type FlatIter[From, To any] struct {
	// contains filtered or unexported fields
}

FlatIter is the Iterator wrapper that converts an element to a slice and iterates over the elements of that slice. For example, FlatIter can be used to iterate over all the elements of a multi-dimensional array as if it were a one-dimensional array ([][]int -> []int).

func Flat added in v0.0.8 

func Flat[From, To any](next func() (From, bool), flattener func(From) []To) FlatIter[From, To]

Flat instantiates an iterator that extracts slices of 'To' by a flattener from elements of 'From' and flattens as one iterable collection of 'To' elements.

func (*FlatIter[From, To]) For 

func (i *FlatIter[From, To]) For(walker func(element To) error) error

For takes elements retrieved by the iterator. Can be interrupt by returning ErrBreak

func (*FlatIter[From, To]) ForEach 

func (i *FlatIter[From, To]) ForEach(walker func(element To))

ForEach FlatIter all elements retrieved by the iterator

func (*FlatIter[From, To]) Next 

func (i *FlatIter[From, To]) Next() (To, bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

type KeyValuer 

type KeyValuer[T, K, V any] struct {
	// contains filtered or unexported fields
}

KeyValuer is the Iterator wrapper that converts an element to a key\value pair and iterates over these pairs

func NewKeyValuer 

func NewKeyValuer[T any, K, V any](next func() (T, bool), keyExtractor func(T) K, valsExtractor func(T) V) KeyValuer[T, K, V]

NewKeyValuer creates instance of the KeyValuer

func ToKV 

func ToKV[T any, K comparable, V any](next func() (T, bool), keyExtractor func(T) K, valExtractor func(T) V) KeyValuer[T, K, V]

ToKV transforms iterable elements to key/value iterator based on applying key, value extractors to the elements

func (KeyValuer[T, K, V]) Next 

func (kv KeyValuer[T, K, V]) Next() (key K, value V, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

func (KeyValuer[T, K, V]) Track 

func (kv KeyValuer[T, K, V]) Track(traker func(key K, value V) error) error

Track takes key, value pairs retrieved by the iterator. Can be interrupt by returning ErrBreak

func (KeyValuer[T, K, V]) TrackEach 

func (kv KeyValuer[T, K, V]) TrackEach(traker func(key K, value V))

TrackEach takes all key, value pairs retrieved by the iterator

type Looper 

type Looper[T any, I interface{ Next() (T, bool) }] interface {
	Loop() I
}

Looper provides an iterable loop function

type MultipleKeyValuer 

type MultipleKeyValuer[T, K, V any] struct {
	// contains filtered or unexported fields
}

MultipleKeyValuer is the Iterator wrapper that converts an element to a key\value pair and iterates over these pairs

func FlatKeys added in v0.0.8 

func FlatKeys[T, K, V any](next func() (T, bool), keysExtractor func(T) []K, valExtractor func(T) V) *MultipleKeyValuer[T, K, V]

FlatKeys transforms iterable elements to key/value iterator based on applying key, value extractor to the elements

func FlatValues added in v0.0.8 

func FlatValues[T, K, V any](next func() (T, bool), keyExtractor func(T) K, valsExtractor func(T) []V) *MultipleKeyValuer[T, K, V]

FlatValues transforms iterable elements to key/value iterator based on applying key, value extractor to the elements

func NewMultipleKeyValuer 

func NewMultipleKeyValuer[T any, K, V any](next func() (T, bool), keysExtractor func(T) []K, valsExtractor func(T) []V) MultipleKeyValuer[T, K, V]

NewMultipleKeyValuer creates instance of the MultipleKeyValuer

func ToKVs 

func ToKVs[T, K, V any](next func() (T, bool), keysExtractor func(T) []K, valsExtractor func(T) []V) *MultipleKeyValuer[T, K, V]

ToKVs transforms iterable elements to key/value iterator based on applying key, value extractor to the elements

func (*MultipleKeyValuer[T, K, V]) Next 

func (kv *MultipleKeyValuer[T, K, V]) Next() (key K, value V, ok bool)

Next returns the next element. The ok result indicates whether the element was returned by the iterator. If ok == false, then the iteration must be completed.

func (*MultipleKeyValuer[T, K, V]) Track 

func (kv *MultipleKeyValuer[T, K, V]) Track(traker func(key K, value V) error) error

Track takes key, value pairs retrieved by the iterator. Can be interrupt by returning ErrBreak

func (*MultipleKeyValuer[T, K, V]) TrackEach 

func (kv *MultipleKeyValuer[T, K, V]) TrackEach(traker func(key K, value V))

TrackEach takes all key, value pairs retrieved by the iterator

Source Files

View all Source files

Directories

Path Synopsis
Package conv provides loop converation helpers
 Package conv provides loop converation helpers
Package convert provides loop converation helpers
 Package convert provides loop converation helpers
Package filter provides aliases for loop filtering helpers
 Package filter provides aliases for loop filtering helpers
Package first provides short aliases for loop functions for retrieving a first element
 Package first provides short aliases for loop functions for retrieving a first element
Package flattener provides short aliases for loop functions
 Package flattener provides short aliases for loop functions
Package group provides short aliases for functions that are used to group elements retrieved by a loop
 Package group provides short aliases for functions that are used to group elements retrieved by a loop
Package range_ provides alias for the slice.Range function
 Package range_ provides alias for the slice.Range function
Package sum provides sum.Of alias
 Package sum provides sum.Of alias

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