Introduce new seq package (#34)

example_test.go

@@ -1,6 +1,7 @@
 package gog_test
 
 import (
+	"cmp"
 	"fmt"
 	"slices"
 	"strconv"
@@ -187,14 +188,7 @@ func ExampleEntries() {
 	}
 	target := gog.Entries(source)
 	slices.SortFunc(target, func(first, second gog.KV[string, []int]) int {
-		switch {
-		case first.Key < second.Key:
-			return -1
-		case first.Key > second.Key:
-			return 1
-		default:
-			return 0
-		}
+		return cmp.Compare(first.Key, second.Key)
 	})
 	fmt.Printf("%+v\n", target)
 

go.mod

@@ -1,20 +1,20 @@
 module github.com/mokiat/gog
 
-go 1.22
+go 1.23
 
 require (
-	github.com/onsi/ginkgo/v2 v2.17.1
-	github.com/onsi/gomega v1.32.0
+	github.com/onsi/ginkgo/v2 v2.21.0
+	github.com/onsi/gomega v1.35.1
 )
 
 require (
-	github.com/go-logr/logr v1.4.1 // indirect
-	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 // indirect
+	github.com/go-logr/logr v1.4.2 // indirect
+	github.com/go-task/slim-sprig/v3 v3.0.0 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
-	github.com/google/pprof v0.0.0-20240402174815-29b9bb013b0f // indirect
-	golang.org/x/net v0.22.0 // indirect
-	golang.org/x/sys v0.18.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
-	golang.org/x/tools v0.19.0 // indirect
+	github.com/google/pprof v0.0.0-20241101162523-b92577c0c142 // indirect
+	golang.org/x/net v0.30.0 // indirect
+	golang.org/x/sys v0.26.0 // indirect
+	golang.org/x/text v0.19.0 // indirect
+	golang.org/x/tools v0.26.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,35 +1,32 @@
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/go-logr/logr v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
-github.com/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
-github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 h1:tfuBGBXKqDEevZMzYi5KSi8KkcZtzBcTgAUUtapy0OI=
-github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572/go.mod h1:9Pwr4B2jHnOSGXyyzV8ROjYa2ojvAY6HCGYYfMoC3Ls=
+github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
+github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-task/slim-sprig/v3 v3.0.0 h1:sUs3vkvUymDpBKi3qH1YSqBQk9+9D/8M2mN1vB6EwHI=
+github.com/go-task/slim-sprig/v3 v3.0.0/go.mod h1:W848ghGpv3Qj3dhTPRyJypKRiqCdHZiAzKg9hl15HA8=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/pprof v0.0.0-20240402174815-29b9bb013b0f h1:f00RU+zOX+B3rLAmMMkzHUF2h1z4DeYR9tTCvEq2REY=
-github.com/google/pprof v0.0.0-20240402174815-29b9bb013b0f/go.mod h1:kf6iHlnVGwgKolg33glAes7Yg/8iWP8ukqeldJSO7jw=
-github.com/onsi/ginkgo/v2 v2.17.1 h1:V++EzdbhI4ZV4ev0UTIj0PzhzOcReJFyJaLjtSF55M8=
-github.com/onsi/ginkgo/v2 v2.17.1/go.mod h1:llBI3WDLL9Z6taip6f33H76YcWtJv+7R3HigUjbIBOs=
-github.com/onsi/gomega v1.32.0 h1:JRYU78fJ1LPxlckP6Txi/EYqJvjtMrDC04/MM5XRHPk=
-github.com/onsi/gomega v1.32.0/go.mod h1:a4x4gW6Pz2yK1MAmvluYme5lvYTn61afQ2ETw/8n4Lg=
+github.com/google/pprof v0.0.0-20241101162523-b92577c0c142 h1:sAGdeJj0bnMgUNVeUpp6AYlVdCt3/GdI3pGRqsNSQLs=
+github.com/google/pprof v0.0.0-20241101162523-b92577c0c142/go.mod h1:vavhavw2zAxS5dIdcRluK6cSGGPlZynqzFM8NdvU144=
+github.com/onsi/ginkgo/v2 v2.21.0 h1:7rg/4f3rB88pb5obDgNZrNHrQ4e6WpjonchcpuBRnZM=
+github.com/onsi/ginkgo/v2 v2.21.0/go.mod h1:7Du3c42kxCUegi0IImZ1wUQzMBVecgIHjR1C+NkhLQo=
+github.com/onsi/gomega v1.35.1 h1:Cwbd75ZBPxFSuZ6T+rN/WCb/gOc6YgFBXLlZLhC7Ds4=
+github.com/onsi/gomega v1.35.1/go.mod h1:PvZbdDc8J6XJEpDK4HCuRBm8a6Fzp9/DmhC9C7yFlog=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
-github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-golang.org/x/net v0.22.0 h1:9sGLhx7iRIHEiX0oAJ3MRZMUCElJgy7Br1nO+AMN3Tc=
-golang.org/x/net v0.22.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
-golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
-golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/tools v0.19.0 h1:tfGCXNR1OsFG+sVdLAitlpjAvD/I6dHDKnYrpEZUHkw=
-golang.org/x/tools v0.19.0/go.mod h1:qoJWxmGSIBmAeriMx19ogtrEPrGtDbPK634QFIcLAhc=
-google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
-google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/net v0.30.0 h1:AcW1SDZMkb8IpzCdQUaIq2sP4sZ4zw+55h6ynffypl4=
+golang.org/x/net v0.30.0/go.mod h1:2wGyMJ5iFasEhkwi13ChkO/t1ECNC4X4eBKkVFyYFlU=
+golang.org/x/sys v0.26.0 h1:KHjCJyddX0LoSTb3J+vWpupP9p0oznkqVk/IfjymZbo=
+golang.org/x/sys v0.26.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.19.0 h1:kTxAhCbGbxhK0IwgSKiMO5awPoDQ0RpfiVYBfK860YM=
+golang.org/x/text v0.19.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+golang.org/x/tools v0.26.0 h1:v/60pFQmzmT9ExmjDv2gGIfi3OqfKoEP6I5+umXlbnQ=
+golang.org/x/tools v0.26.0/go.mod h1:TPVVj70c7JJ3WCazhD8OdXcZg/og+b9+tH/KxylGwH0=
+google.golang.org/protobuf v1.35.1 h1:m3LfL6/Ca+fqnjnlqQXNpFPABW1UD7mjh8KO2mKFytA=
+google.golang.org/protobuf v1.35.1/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

seq/collect.go

@@ -0,0 +1,14 @@
+package seq
+
+import (
+	"iter"
+	"slices"
+)
+
+// CollectCap collects values from src into a new slice with the given capacity
+// preallocated and returns it.
+func CollectCap[T any](src iter.Seq[T], cap int) []T {
+	result := make([]T, 0, cap)
+	result = slices.AppendSeq(result, src)
+	return result
+}

seq/collect_test.go

@@ -0,0 +1,25 @@
+package seq_test
+
+import (
+	"slices"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/mokiat/gog/seq"
+)
+
+var _ = Describe("Collect", func() {
+
+	Describe("CollectCap", func() {
+
+		It("collects values from sequence into new slice with given capacity", func() {
+			iter := slices.Values([]int{1, 2, 3})
+			result := seq.CollectCap(iter, 5)
+			Expect(result).To(Equal([]int{1, 2, 3}))
+			Expect(result).To(HaveCap(5))
+		})
+
+	})
+
+})

seq/doc.go

@@ -0,0 +1,2 @@
+// Package seq provides helpful iterator functions.
+package seq

seq/example_test.go

@@ -0,0 +1,83 @@
+package seq_test
+
+import (
+	"fmt"
+
+	"github.com/mokiat/gog/seq"
+)
+
+func ExampleTimes() {
+	for v := range seq.Times(3) {
+		fmt.Println(v)
+	}
+
+	// Output:
+	// 0
+	// 1
+	// 2
+}
+
+func ExampleRange() {
+	for v := range seq.Range(1, 3) {
+		fmt.Println(v)
+	}
+
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+
+func ExampleMap() {
+	source := seq.Times(4)
+	target := seq.Map(source, func(v int) string {
+		return fmt.Sprintf("item %d", v)
+	})
+	for v := range target {
+		fmt.Println(v)
+	}
+
+	// Output:
+	// item 0
+	// item 1
+	// item 2
+	// item 3
+}
+
+func ExampleCollectCap() {
+	source := seq.Times(4)
+	target := seq.CollectCap(source, 12)
+	for _, v := range target {
+		fmt.Println(v)
+	}
+	fmt.Println()
+	fmt.Println(cap(target))
+
+	// Output:
+	// 0
+	// 1
+	// 2
+	// 3
+	//
+	// 12
+}
+
+func ExampleBatchSlice() {
+	source := []string{
+		"1Hello", "1World",
+		"2This", "2Is", "2Longer",
+		"3Yes",
+	}
+	eqFn := func(a, b string) bool {
+		return a[0] == b[0]
+	}
+
+	for batch := range seq.BatchSlice(source, eqFn, 0) {
+		fmt.Printf("%#v\n", batch)
+	}
+
+	// Output:
+	// []string{"1Hello", "1World"}
+	// []string{"2This", "2Is", "2Longer"}
+	// []string{"3Yes"}
+}

seq/range.go

@@ -0,0 +1,40 @@
+package seq
+
+import "iter"
+
+// None returns an empty sequence.
+func None[T any]() iter.Seq[T] {
+	return func(yield func(T) bool) {}
+}
+
+// Times returns a sequence of integers from 0 to count.
+func Times(count int) iter.Seq[int] {
+	return func(yield func(int) bool) {
+		for i := range count {
+			if !yield(i) {
+				return
+			}
+		}
+	}
+}
+
+// Range returns a sequence of integers from from (inclusive) to to (inclusive).
+//
+// If from is greater than to, the sequence will be in descending order.
+func Range(from, to int) iter.Seq[int] {
+	return func(yield func(int) bool) {
+		if from < to {
+			for i := from; i <= to; i++ {
+				if !yield(i) {
+					return
+				}
+			}
+		} else {
+			for i := from; i >= to; i-- {
+				if !yield(i) {
+					return
+				}
+			}
+		}
+	}
+}

seq/range_test.go

@@ -0,0 +1,44 @@
+package seq_test
+
+import (
+	"slices"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/mokiat/gog/seq"
+)
+
+var _ = Describe("Range", func() {
+
+	Describe("None", func() {
+		It("yields no values", func() {
+			iter := seq.None[int]()
+			result := slices.Collect(iter)
+			Expect(result).To(BeEmpty())
+		})
+	})
+
+	Describe("Times", func() {
+		It("yields the correct sequence of numbers", func() {
+			iter := seq.Times(3)
+			result := slices.Collect(iter)
+			Expect(result).To(Equal([]int{0, 1, 2}))
+		})
+	})
+
+	Describe("Range", func() {
+		It("yields the correct sequence of numbers", func() {
+			iter := seq.Range(1, 3)
+			result := slices.Collect(iter)
+			Expect(result).To(Equal([]int{1, 2, 3}))
+		})
+
+		It("works in reverse as well", func() {
+			iter := seq.Range(3, 1)
+			result := slices.Collect(iter)
+			Expect(result).To(Equal([]int{3, 2, 1}))
+		})
+	})
+
+})

seq/suite_test.go

@@ -0,0 +1,13 @@
+package seq_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestSeq(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Sequence Suite")
+}