Add support for iter.Seq for ScanIterator

khasanovbi · khasanovbi · commit 814ac4263b7f · 2025-04-17T03:20:07.000+03:00
diff --git a/README.md b/README.md
@@ -15,7 +15,7 @@ In `go-redis` we are aiming to support the last three releases of Redis. Current
 - [Redis 7.4](https://raw.githubusercontent.com/redis/redis/7.4/00-RELEASENOTES) - using Redis Stack 7.4 for modules support
 - [Redis 8.0](https://raw.githubusercontent.com/redis/redis/8.0/00-RELEASENOTES) - using Redis CE 8.0 where modules are included
 
-Although the `go.mod` states it requires at minimum `go 1.18`, our CI is configured to run the tests against all three
+Although the `go.mod` states it requires at minimum `go 1.23`, our CI is configured to run the tests against all three
 versions of Redis and latest two versions of Go ([1.23](https://go.dev/doc/devel/release#go1.23.0),
 [1.24](https://go.dev/doc/devel/release#go1.24.0)). We observe that some modules related test may not pass with
 Redis Stack 7.2 and some commands are changed with Redis CE 8.0.
diff --git a/example/del-keys-without-ttl/go.mod b/example/del-keys-without-ttl/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/del-keys-without-ttl
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example/del-keys-without-ttl/main.go b/example/del-keys-without-ttl/main.go
@@ -28,8 +28,8 @@ func main() {
 	checker.Start(ctx)
 
 	iter := rdb.Scan(ctx, 0, "", 0).Iterator()
-	for iter.Next(ctx) {
-		checker.Add(iter.Val())
+	for val := range iter.Vals(ctx) {
+		checker.Add(val)
 	}
 	if err := iter.Err(); err != nil {
 		panic(err)
diff --git a/example/hll/go.mod b/example/hll/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/hll
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example/hset-struct/go.mod b/example/hset-struct/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/scan-struct
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example/lua-scripting/go.mod b/example/lua-scripting/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/lua-scripting
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example/redis-bloom/go.mod b/example/redis-bloom/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/redis-bloom
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example/scan-struct/go.mod b/example/scan-struct/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/example/scan-struct
 
-go 1.18
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/example_test.go b/example_test.go
@@ -632,8 +632,8 @@ func Example_customCommand2() {
 
 func ExampleScanIterator() {
 	iter := rdb.Scan(ctx, 0, "", 0).Iterator()
-	for iter.Next(ctx) {
-		fmt.Println(iter.Val())
+	for val := range iter.Vals(ctx) {
+		fmt.Println(val)
 	}
 	if err := iter.Err(); err != nil {
 		panic(err)
@@ -642,8 +642,8 @@ func ExampleScanIterator() {
 
 func ExampleScanCmd_Iterator() {
 	iter := rdb.Scan(ctx, 0, "", 0).Iterator()
-	for iter.Next(ctx) {
-		fmt.Println(iter.Val())
+	for val := range iter.Vals(ctx) {
+		fmt.Println(val)
 	}
 	if err := iter.Err(); err != nil {
 		panic(err)
diff --git a/extra/rediscensus/go.mod b/extra/rediscensus/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/extra/rediscensus/v9
 
-go 1.19
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/extra/rediscmd/go.mod b/extra/rediscmd/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/extra/rediscmd/v9
 
-go 1.19
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/extra/redisotel/go.mod b/extra/redisotel/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/extra/redisotel/v9
 
-go 1.19
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/extra/redisprometheus/go.mod b/extra/redisprometheus/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/extra/redisprometheus/v9
 
-go 1.19
+go 1.23
 
 replace github.com/redis/go-redis/v9 => ../..
 
diff --git a/go.mod b/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/v9
 
-go 1.18
+go 1.23
 
 require (
 	github.com/bsm/ginkgo/v2 v2.12.0
diff --git a/internal/customvet/go.mod b/internal/customvet/go.mod
@@ -1,6 +1,6 @@
 module github.com/redis/go-redis/internal/customvet
 
-go 1.17
+go 1.23
 
 require golang.org/x/tools v0.5.0
 
diff --git a/iterator.go b/iterator.go
@@ -2,6 +2,7 @@ package redis
 
 import (
 	"context"
+	"iter"
 )
 
 // ScanIterator is used to incrementally iterate over a collection of elements.
@@ -16,6 +17,8 @@ func (it *ScanIterator) Err() error {
 }
 
 // Next advances the cursor and returns true if more values can be read.
+//
+// Deprecated: support for native iterators has been added in go 1.23. Use Vals instead.
 func (it *ScanIterator) Next(ctx context.Context) bool {
 	// Instantly return on errors.
 	if it.cmd.Err() != nil {
@@ -57,10 +60,23 @@ func (it *ScanIterator) Next(ctx context.Context) bool {
 }
 
 // Val returns the key/field at the current cursor position.
+//
+// Deprecated: support for native iterators has been added in go 1.23. Use Vals instead.
 func (it *ScanIterator) Val() string {
 	var v string
 	if it.cmd.Err() == nil && it.pos > 0 && it.pos <= len(it.cmd.page) {
 		v = it.cmd.page[it.pos-1]
 	}
 	return v
 }
+
+// Vals returns iterator over key/field at the current cursor position.
+func (it *ScanIterator) Vals(ctx context.Context) iter.Seq[string] {
+	return func(yield func(string) bool) {
+		for it.Next(ctx) {
+			if !yield(it.Val()) {
+				return
+			}
+		}
+	}
+}
diff --git a/iterator_test.go b/iterator_test.go
@@ -2,6 +2,7 @@ package redis_test
 
 import (
 	"fmt"
+	"slices"
 
 	. "github.com/bsm/ginkgo/v2"
 	. "github.com/bsm/gomega"
@@ -52,13 +53,20 @@ var _ = Describe("ScanIterator", func() {
 		Expect(client.Close()).NotTo(HaveOccurred())
 	})
 
-	It("should scan across empty DBs", func() {
+	It("should scan across empty DBs using Next", func() {
 		iter := client.Scan(ctx, 0, "", 10).Iterator()
 		Expect(iter.Next(ctx)).To(BeFalse())
 		Expect(iter.Err()).NotTo(HaveOccurred())
 	})
 
-	It("should scan across one page", func() {
+	It("should scan across empty DBs using Vals", func() {
+		iter := client.Scan(ctx, 0, "", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(vals).To(BeEmpty())
+		Expect(iter.Err()).NotTo(HaveOccurred())
+	})
+
+	It("should scan across one page using Next", func() {
 		Expect(seed(7)).NotTo(HaveOccurred())
 
 		var vals []string
@@ -70,7 +78,16 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(ConsistOf([]string{"K01", "K02", "K03", "K04", "K05", "K06", "K07"}))
 	})
 
-	It("should scan across multiple pages", func() {
+	It("should scan across one page using Vals", func() {
+		Expect(seed(7)).NotTo(HaveOccurred())
+
+		iter := client.Scan(ctx, 0, "", 0).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(ConsistOf([]string{"K01", "K02", "K03", "K04", "K05", "K06", "K07"}))
+	})
+
+	It("should scan across multiple pages using Next", func() {
 		Expect(seed(71)).NotTo(HaveOccurred())
 
 		var vals []string
@@ -84,7 +101,18 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(ContainElement("K71"))
 	})
 
-	It("should hscan across multiple pages", func() {
+	It("should scan across multiple pages using Vals", func() {
+		Expect(seed(71)).NotTo(HaveOccurred())
+
+		iter := client.Scan(ctx, 0, "", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(71))
+		Expect(vals).To(ContainElement("K01"))
+		Expect(vals).To(ContainElement("K71"))
+	})
+
+	It("should hscan across multiple pages using Next", func() {
 		SkipBeforeRedisVersion(7.4, "doesn't work with older redis stack images")
 		Expect(hashSeed(71)).NotTo(HaveOccurred())
 
@@ -100,7 +128,20 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(ContainElement("x"))
 	})
 
-	It("should hscan without values across multiple pages", Label("NonRedisEnterprise"), func() {
+	It("should hscan across multiple pages using Vals", func() {
+		SkipBeforeRedisVersion(7.4, "doesn't work with older redis stack images")
+		Expect(hashSeed(71)).NotTo(HaveOccurred())
+
+		iter := client.HScan(ctx, hashKey, 0, "", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(71 * 2))
+		Expect(vals).To(ContainElement("K01"))
+		Expect(vals).To(ContainElement("K71"))
+		Expect(vals).To(ContainElement("x"))
+	})
+
+	It("should hscan without values across multiple pages using Next", Label("NonRedisEnterprise"), func() {
 		SkipBeforeRedisVersion(7.4, "doesn't work with older redis stack images")
 		Expect(hashSeed(71)).NotTo(HaveOccurred())
 
@@ -116,7 +157,20 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).NotTo(ContainElement("x"))
 	})
 
-	It("should scan to page borders", func() {
+	It("should hscan without values across multiple pages using Vals", Label("NonRedisEnterprise"), func() {
+		SkipBeforeRedisVersion(7.4, "doesn't work with older redis stack images")
+		Expect(hashSeed(71)).NotTo(HaveOccurred())
+
+		iter := client.HScanNoValues(ctx, hashKey, 0, "", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(71))
+		Expect(vals).To(ContainElement("K01"))
+		Expect(vals).To(ContainElement("K71"))
+		Expect(vals).NotTo(ContainElement("x"))
+	})
+
+	It("should scan to page borders using Next", func() {
 		Expect(seed(20)).NotTo(HaveOccurred())
 
 		var vals []string
@@ -128,7 +182,16 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(HaveLen(20))
 	})
 
-	It("should scan with match", func() {
+	It("should scan to page borders using Vals", func() {
+		Expect(seed(20)).NotTo(HaveOccurred())
+
+		iter := client.Scan(ctx, 0, "", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(20))
+	})
+
+	It("should scan with match using Next", func() {
 		Expect(seed(33)).NotTo(HaveOccurred())
 
 		var vals []string
@@ -140,7 +203,16 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(HaveLen(13))
 	})
 
-	It("should scan with match across empty pages", func() {
+	It("should scan with match using Vals", func() {
+		Expect(seed(33)).NotTo(HaveOccurred())
+
+		iter := client.Scan(ctx, 0, "K*2*", 10).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(13))
+	})
+
+	It("should scan with match across empty pages using Next", func() {
 		Expect(extraSeed(2, 10)).NotTo(HaveOccurred())
 
 		var vals []string
@@ -151,4 +223,13 @@ var _ = Describe("ScanIterator", func() {
 		Expect(iter.Err()).NotTo(HaveOccurred())
 		Expect(vals).To(HaveLen(2))
 	})
+
+	It("should scan with match across empty pages using Vals", func() {
+		Expect(extraSeed(2, 10)).NotTo(HaveOccurred())
+
+		iter := client.Scan(ctx, 0, "K*", 1).Iterator()
+		vals := slices.Collect(iter.Vals(ctx))
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(2))
+	})
 })

-Original file line number
+Diff line change
@@ @@ -1,6 +1,6 @@ @@
 module github.com/redis/go-redis/example/del-keys-without-ttl
 -go 1.18
 +go 1.23
 replace github.com/redis/go-redis/v9 => ../..