README
¶
itermore
range iterables with more features
Description
This package provides a set of functions to work with iterables in Go. It is partially inspired by Python's itertools module.
Available utils include for now:
- iterator combinators:
Chain,Zip,Skip,Take, etc. - iterator destructors:
Collect,CollectJoin,CollectMap, etc. - iterator constructors:
Items,For,ChanCtx, etc.
To use this package you need go 1.22 or later and you need to enable the rangefunc experiment until it is enabled by default.
export GOEXPERIMENT=rangefunc
Examples
func ExampleCollectJoin() {
iter := itermore.Items("a", "b", "c")
str := &strings.Builder{}
itermore.CollectJoin(str, iter, ", ")
fmt.Println(str.String())
// Output: a, b, c
}
func ExampleChain() {
one := itermore.One(1)
xx := itermore.Items(10, 20, 30)
for x := range itermore.Chain(one, xx) {
fmt.Println(x)
}
// Output: 1
// 10
// 20
// 30
}
func ExampleZip() {
xx := itermore.Items(10, 20, 30)
yy := itermore.Items("a", "b", "c")
for x, y := range itermore.Zip(xx, yy) {
fmt.Println(x, y)
}
// Output: 10 a
// 20 b
// 30 c
}
Roadmap
- group by
- iterable versions of standard library functions
Documentation
¶
Index ¶
- func Chain[E any](seqs ...iter.Seq[E]) iter.Seq[E]
- func Chan[E any](ch <-chan E) iter.Seq[E]
- func ChanCtx[E any](ctx context.Context, ch <-chan E) iter.Seq[E]
- func Collect[S ~[]E, E any](dst S, seq iter.Seq[E]) S
- func CollectChan[E any](ch chan<- E, seq iter.Seq[E])
- func CollectChanCtx[E any](ctx context.Context, ch chan<- E, seq iter.Seq[E])
- func CollectJoin[S ~string](wr io.StringWriter, seq iter.Seq[S], sep string) (int64, error)
- func CollectJoinBytes[P ~[]byte](wr io.Writer, seq iter.Seq[P], sep []byte) (int64, error)
- func CollectKeys[S ~map[K]V, K comparable, V any](dst S, value V, seq iter.Seq[K])
- func CollectMap[M ~map[K]V, K comparable, V any](dst M, seq iter.Seq2[K, V])
- func Compact[E comparable](seq iter.Seq[E]) iter.Seq[E]
- func Enumerate[E any](seq iter.Seq[E]) iter.Seq2[int, E]
- func FlattenSlices[E any](seq iter.Seq[[]E]) iter.Seq[E]
- func For[N Number](start, to, step N) iter.Seq[N]
- func Forever[E any](value E) iter.Seq[E]
- func ForeverFn[E any](fn func() E) iter.Seq[E]
- func Items[E any](items ...E) iter.Seq[E]
- func Loop[E any](items []E) iter.Seq[E]
- func Map[K comparable, V any](m map[K]V) iter.Seq2[K, V]
- func Max[E cmp.Ordered](seq iter.Seq[E]) (E, bool)
- func Min[E cmp.Ordered](seq iter.Seq[E]) (E, bool)
- func Next[E any](next func() (E, bool)) iter.Seq[E]
- func None[E any](yield func(E) bool)
- func None2[A, B any](yield func(A, B) bool)
- func One[E any](value E) iter.Seq[E]
- func One2[A, B any](a A, b B) iter.Seq2[A, B]
- func SkipN[E any](n int, seq iter.Seq[E]) iter.Seq[E]
- func Slice[E any](items []E) iter.Seq[E]
- func TakeN[E any](n int, seq iter.Seq[E]) iter.Seq[E]
- func Then[E any](seq iter.Seq[E], then func()) iter.Seq[E]
- func YieldFrom[E any](yield func(E) bool, seq iter.Seq[E]) bool
- func YieldFrom2[A, B any](yield func(A, B) bool, seq iter.Seq2[A, B]) bool
- func Zip[A, B any](a iter.Seq[A], b iter.Seq[B]) iter.Seq2[A, B]
- func ZipLongest[A, B any](a iter.Seq[A], b iter.Seq[B]) iter.Seq2[A, B]
- type Number
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Chain ¶
Chain creates a sequence that yields values from all provided sequences. Values are yielded in the order they appear in the arguments.
Example ¶
package main
import (
"fmt"
"github.com/ninedraft/itermore"
)
func main() {
one := itermore.One(1)
xx := itermore.Items(10, 20, 30)
for x := range itermore.Chain(one, xx) {
fmt.Println(x)
}
}
Output: 1 10 20 30
func Chan ¶
Chan returns a new sequence that iterates over values from the given channel. If channel is nil, Chan returns an empty sequence. Closing channel will stop iteration.
func ChanCtx ¶
ChanCtx returns a new sequence that iterates over values from the given channel. If channel is nil, Chan returns an empty sequence. Closing channel will stop iteration. If ctx is canceled, ChanCtx will stop iteration.
Example ¶
package main
import (
"context"
"fmt"
"github.com/ninedraft/itermore"
)
func main() {
ch := make(chan int, 3)
ch <- 10
ch <- 20
ch <- 30
close(ch)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
// easy cancelation of range-over-chan loop
iter := itermore.ChanCtx(ctx, ch)
for x := range iter {
fmt.Println(x)
}
}
Output: 10 20 30
func Collect ¶
Collect writes values from provided sequence to the given slice. If dst slice is nil, Collect will create a new slice. It can return a new slice or the same slice that was passed as dst following the same rules as append function.
func CollectChan ¶
func CollectJoin ¶
CollectJoin writes values from provided sequence to the given writer.
Example ¶
package main
import (
"fmt"
"strings"
"github.com/ninedraft/itermore"
)
func main() {
iter := itermore.Items("a", "b", "c")
str := &strings.Builder{}
itermore.CollectJoin(str, iter, ", ")
fmt.Println(str.String())
}
Output: a, b, c
func CollectJoinBytes ¶
CollectJoinBytes writes values from provided sequence to the given writer.
func CollectKeys ¶
func CollectKeys[S ~map[K]V, K comparable, V any](dst S, value V, seq iter.Seq[K])
CollectKeys writes keys from provided sequence to the given map and assigns them the given value. It can be used to create a set from a sequence. It will panic if dst is nil.
func CollectMap ¶
func CollectMap[M ~map[K]V, K comparable, V any](dst M, seq iter.Seq2[K, V])
CollectMap writes key-value pairs from provided sequence to the given map. It will panic if dst is nil.
func Compact ¶
func Compact[E comparable](seq iter.Seq[E]) iter.Seq[E]
Compact returns a sequence, which yields values from seq, but skips consecutive duplicates. It roughly equal to slices.Compact.
func Enumerate ¶
Enumerate creates a sequence that yields values from the given sequence with their indexes. If number of values in the sequence is greater then math.MaxInt, counter will wrap around.
func FlattenSlices ¶ added in v0.2.0
FlattenSlices walks through provided sequence and emits each element from sequenced slice.
Example:
[1, 2, 3] [4, 5, 6] -> 1, 2, 3, 4, 5, 6
Example ¶
package main
import (
"fmt"
"github.com/ninedraft/itermore"
)
func main() {
rows := itermore.Slice([][]int{
{1, 2},
{3, 4},
})
items := itermore.FlattenSlices(rows)
for x := range items {
fmt.Printf("%d ", x)
}
}
Output: 1 2 3 4
func For ¶
For behaves like a for loop with a counter. It can be though as following code:
start <= to: for i := start; i < to; i += step start > to: for i := start; i > to; i += step
func ForeverFn ¶
ForeverFn creates an infinite sequence that yields a single value from the given function.
func Items ¶
Items creates a sequence that yields values from the given variadic arguments. If no arguments are provided, the sequence will be empty. It's a shortcut for Slice([]E{items...}).
func Loop ¶
Loop forever yields values from the given slice in the order they appear in the slice. After the last value is yielded, the sequence will start from the beginning.
func Map ¶
func Map[K comparable, V any](m map[K]V) iter.Seq2[K, V]
Map creates a sequence that yields key-value pairs from the given map. If map nil or empty, the sequence will be empty.
func Max ¶
Max returns the largest element in the sequence. If sequence is empty, Max returns false. If there is a single item in the sequence, Max returns it. It roughly equal to slices.Max.
func Min ¶
Min returns the smallest element in the sequence. If sequence is empty, Min returns false. If there is a single item in the sequence, Min returns it. It roughly equal to slices.Min.
func SkipN ¶
SkipN skips first n values from the given sequence. If n is greater then number of values in the sequence, SkipN will return an empty sequence. If n is negative or zero, SkipN will return an empty sequence.
func Slice ¶
Slice creates a sequence that yields values from the given slice. If slice is nil or empty, the sequence will be empty.
func TakeN ¶
TakeN yields first n values from the given sequence. If n is greater then number of values in the sequence, TakeN will yield all values from the sequence. If n is negative or zero, TakeN will return an empty sequence.
func Then ¶
Then returns a sequence, which yields values from seq, then always calls then function. It calls then function even if seq is empty.
func YieldFrom2 ¶
YieldFrom2 pulls all pairs from the given sequence and yields them.
func Zip ¶
Zip creates a sequence that yields pairs of values from the given sequences. If any of the sequences is stopped, the sequence will stop.
Example ¶
package main
import (
"fmt"
"github.com/ninedraft/itermore"
)
func main() {
xx := itermore.Items(10, 20, 30)
yy := itermore.Items("a", "b", "c")
for x, y := range itermore.Zip(xx, yy) {
fmt.Println(x, y)
}
}
Output: 10 a 20 b 30 c
func ZipLongest ¶
ZipLongest creates a sequence that yields pairs of values from the given sequences. If any of the sequences is stopped, the sequence will continue to emit zero values for that sequence. If both sequences are stopped, the sequence will stop.
Types ¶
type Number ¶
type Number interface {
constraints.Integer | constraints.Float
}
Number is a type, which can be added and compared.
Source Files