README
¶
Itertools for Go using iterators.
Contents
Installation
$ go get github.com/kafkiansky/itertools
Usage
The itertools package consists from two subpackages: iterslice and itermap for working with slices and maps as iterators separately.
iterslice
Iterator
Creates an iterator from slice.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Iterator([]int{1, 2, 3}) {
log.Println(v)
}
}
Filter
Filters an iter.Seq[T].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Filter(
iterslice.Iterator([]int{1, 2, 3}),
func(v int) bool {
return v%2 == 0
},
) {
log.Println(v)
}
}
Map
Apply F to an iter.Seq[T] returning new iter.Seq[E].
package main
import (
"log"
"strconv"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Map(
iterslice.Iterator([]int{1, 2, 3}),
strconv.Itoa,
) {
log.Println(v)
}
}
TryMap
Works as Map but with errors.
package main
import (
"log"
"strconv"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v, err := range iterslice.TryMap(
iterslice.Iterator([]string{"1", "2", "invalid"}),
strconv.Atoi,
) {
if err != nil {
log.Println(err)
} else {
log.Println(v)
}
}
}
Each
Iterates over an iter.Seq[T] and applies F.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
iterslice.Each(
iterslice.Iterator([]int{1, 2, 3}),
func(v int) {
log.Println(v)
},
)
}
First
Yields the first element from an iter.Seq[T].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.First(
iterslice.Iterator([]int{6, 7, 8}),
),
) // 6, true
}
Last
Yield the last element from an iter.Seq[T].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Last(
iterslice.Iterator([]int{6, 7, 8}),
),
) // 8, true
}
Nth
Yields the N element from iter.Seq[T]. Index starts from 1.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Nth(
iterslice.Iterator([]int{6, 7, 8}),
2,
),
) // 7, true
}
Range
Creates an iterator from sequence.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Range(5) {
log.Println(v)
}
}
Between
Creates an iterator starting from left value to rigth exclusive.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Between(5, 10) {
log.Println(v)
}
}
Reduce
Reduces an iter.Seq[T] to a single value using an F. Optional accepts an initial value.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Reduce(
iterslice.Iterator([]int{1, 2, 3}),
func(a, b int) int { return a + b },
),
) // 6
}
Split
Splits string using separator and yield chunks as an iter.Seq[string].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Split("a,b,c", ",") {
log.Println(v)
}
}
Chars
Yield string chars as runes.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Chars("итератор") {
log.Println(v)
}
}
ConsumeChannel
Consume values from an chan T and yields values as iter.Seq[T] until channel closes.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
c := make(chan int, 3)
for v := range 3 {
c <- v
}
close(c)
for v := range iterslice.ConsumeChannel(c) {
log.Println(v)
}
}
Partition
Creates two iterators from one using F.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
even, odd := iterslice.Partition(
iterslice.Iterator([]int{1, 2, 3}),
func(v int) bool {
return v%2 == 0
},
)
for v := range even {
log.Printf("even: %d", v)
}
for v := range odd {
log.Printf("odd: %d", v)
}
}
Position
Search index of value in an iterator.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Position(
iterslice.Iterator([]int{1, 2, 3}),
2,
),
) // 1 (index of value 2)
}
Max
Search the max value in an iter.Seq[constraints.Order].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Max(
iterslice.Iterator([]int{10, 2, 3}),
),
)
}
Min
Search the min value in an iter.Seq[constraints.Ordered].
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
iterslice.Min(
iterslice.Iterator([]int{-10, -2, -3}),
),
) // -10
}
Join
Joins n iterators to the single one.
package main
import (
"log"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
for v := range iterslice.Join(
iterslice.Between(0, 3),
iterslice.Between(6, 10),
) {
log.Println(v)
}
}
itermap
Iterator
Creates an iterator iter.Seq2[K, V] from map[K]V.
package main
import (
"log"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
for k, v := range itermap.Iterator(map[string]int{"x": 1, "y": 2}) {
log.Printf("key: %s, value: %d", k, v)
}
}
Keys
Creates an iterator iter.Seq[K] from map keys.
package main
import (
"log"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
for k := range itermap.Keys(
map[string]int{"x": 1, "y": 2},
) {
log.Printf("key: %s", k)
}
}
Values
Creates an iterator iter.Seq[V] from map values.
package main
import (
"log"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
for v := range itermap.Values(
map[string]int{"x": 1, "y": 2},
) {
log.Printf("value: %d", v)
}
}
Each
Iterates over an iter.Seq2[K, V] an applies F for each key-value pair.
package main
import (
"log"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
itermap.Each(
itermap.Iterator(map[string]int{"x": 1, "y": 2}),
func(k string, v int) {
log.Printf("key: %s, value: %d", k, v)
},
)
}
Join
Joins n iterators iter.Seq[K, V] to the single one.
package main
import (
"log"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
for k, v := range itermap.Join(
itermap.Iterator(map[string]int{"x": 1, "y": 2}),
itermap.Iterator(map[string]int{"z": 3}),
) {
log.Printf("key: %s, value: %d", k, v)
}
}
CollectSlice
Collects an iter.Seq[T] to the slice []T.
package main
import (
"log"
"github.com/kafkiansky/itertools"
"github.com/kafkiansky/itertools/iterslice"
)
func main() {
log.Println(
itertools.CollectSlice(
iterslice.Between(5, 10),
),
) // [5, 6, 7, 8, 9]
}
CollectMap
Collects an iter.Seq2[K, V] to the map map[K]V.
package main
import (
"log"
"github.com/kafkiansky/itertools"
"github.com/kafkiansky/itertools/itermap"
)
func main() {
log.Println(
itertools.CollectMap(
itermap.Iterator(map[string]int{"x": 1, "y": 2}),
),
) // map[x:1 y:2]
}
Testing
$ GOEXPERIMENT=rangefunc go test ./...
License
The MIT License (MIT). See License File for more information.
Documentation
¶
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CollectMap ¶
func CollectMap[K comparable, V any](seq iter.Seq2[K, V]) map[K]V
CollectMap collects values from iter.Seq2[K, V] to map[K]V.
func CollectSlice ¶
CollectSlice collects values from iter.Seq[T] to []T.
Types ¶
This section is empty.
Source Files
Directories