bytes,strings: add some examples

Change-Id: Ic93ad59119f3549c0f13c4f366f71e9d01b88c47
GitHub-Last-Rev: afb518047288976f440d3fe0d65923c1905a9b26
GitHub-Pull-Request: golang/go#57907
Reviewed-on: https://go-review.googlesource.com/c/go/+/462283
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>

diff --git a/src/bytes/example_test.go b/src/bytes/example_test.go
index 54a7aa6ae6c04960ce88f6b0d9cabbc01b46acbe..e5b7b60dbba6728904eefc1f5d92017a1a8a6125 100644 (file)
--- a/src/bytes/example_test.go
+++ b/src/bytes/example_test.go
@@ -110,6 +110,19 @@ func ExampleBuffer_ReadByte() {
        // bcde
 }
 
+func ExampleClone() {
+       b := []byte("abc")
+       clone := bytes.Clone(b)
+       fmt.Printf("%s\n", clone)
+       clone[0] = 'd'
+       fmt.Printf("%s\n", b)
+       fmt.Printf("%s\n", clone)
+       // Output:
+       // abc
+       // abc
+       // dbc
+}
+
 func ExampleCompare() {
        // Interpret Compare's result by comparing it to zero.
        var a, b []byte
@@ -210,6 +223,30 @@ func ExampleCut() {
        // Cut("Gopher", "Badger") = "Gopher", "", false
 }
 
+func ExampleCutPrefix() {
+       show := func(s, sep string) {
+               after, found := bytes.CutPrefix([]byte(s), []byte(sep))
+               fmt.Printf("CutPrefix(%q, %q) = %q, %v\n", s, sep, after, found)
+       }
+       show("Gopher", "Go")
+       show("Gopher", "ph")
+       // Output:
+       // CutPrefix("Gopher", "Go") = "pher", true
+       // CutPrefix("Gopher", "ph") = "Gopher", false
+}
+
+func ExampleCutSuffix() {
+       show := func(s, sep string) {
+               before, found := bytes.CutSuffix([]byte(s), []byte(sep))
+               fmt.Printf("CutSuffix(%q, %q) = %q, %v\n", s, sep, before, found)
+       }
+       show("Gopher", "Go")
+       show("Gopher", "er")
+       // Output:
+       // CutSuffix("Gopher", "Go") = "Gopher", false
+       // CutSuffix("Gopher", "er") = "Goph", true
+}
+
 func ExampleEqual() {
        fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
        fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
@@ -347,6 +384,21 @@ func ExampleLastIndexFunc() {
        // -1
 }
 
+func ExampleMap() {
+       rot13 := func(r rune) rune {
+               switch {
+               case r >= 'A' && r <= 'Z':
+                       return 'A' + (r-'A'+13)%26
+               case r >= 'a' && r <= 'z':
+                       return 'a' + (r-'a'+13)%26
+               }
+               return r
+       }
+       fmt.Printf("%s\n", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
+       // Output:
+       // 'Gjnf oevyyvt naq gur fyvgul tbcure...
+}
+
 func ExampleReader_Len() {
        fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
        fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
@@ -445,6 +497,16 @@ func ExampleToTitleSpecial() {
        // ToTitle : AHOJ VÝVOJÁRİ GOLANG
 }
 
+func ExampleToValidUTF8() {
+       fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("abc"), []byte("\uFFFD")))
+       fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("a\xffb\xC0\xAFc\xff"), []byte("")))
+       fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("\xed\xa0\x80"), []byte("abc")))
+       // Output:
+       // abc
+       // abc
+       // abc
+}
+
 func ExampleTrim() {
        fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
        // Output: ["Achtung! Achtung"]

diff --git a/src/strings/example_test.go b/src/strings/example_test.go
index 2a59512ceb9341903d4cb79b5658ca684079854a..ab83e10de45de404bb49a22ca730b6cf3053658c 100644 (file)
--- a/src/strings/example_test.go
+++ b/src/strings/example_test.go
@@ -8,8 +8,19 @@ import (
        "fmt"
        "strings"
        "unicode"
+       "unsafe"
 )
 
+func ExampleClone() {
+       s := "abc"
+       clone := strings.Clone(s)
+       fmt.Println(s == clone)
+       fmt.Println(unsafe.StringData(s) == unsafe.StringData(clone))
+       // Output:
+       // true
+       // false
+}
+
 func ExampleBuilder() {
        var b strings.Builder
        for i := 3; i >= 1; i-- {
@@ -93,6 +104,30 @@ func ExampleCut() {
        // Cut("Gopher", "Badger") = "Gopher", "", false
 }
 
+func ExampleCutPrefix() {
+       show := func(s, sep string) {
+               after, found := strings.CutPrefix(s, sep)
+               fmt.Printf("CutPrefix(%q, %q) = %q, %v\n", s, sep, after, found)
+       }
+       show("Gopher", "Go")
+       show("Gopher", "ph")
+       // Output:
+       // CutPrefix("Gopher", "Go") = "pher", true
+       // CutPrefix("Gopher", "ph") = "Gopher", false
+}
+
+func ExampleCutSuffix() {
+       show := func(s, sep string) {
+               before, found := strings.CutSuffix(s, sep)
+               fmt.Printf("CutSuffix(%q, %q) = %q, %v\n", s, sep, before, found)
+       }
+       show("Gopher", "Go")
+       show("Gopher", "er")
+       // Output:
+       // CutSuffix("Gopher", "Go") = "Gopher", false
+       // CutSuffix("Gopher", "er") = "Goph", true
+}
+
 func ExampleEqualFold() {
        fmt.Println(strings.EqualFold("Go", "go"))
        fmt.Println(strings.EqualFold("AB", "ab")) // true because comparison uses simple case-folding
@@ -402,3 +437,13 @@ func ExampleTrimRightFunc() {
        }))
        // Output: ¡¡¡Hello, Gophers
 }
+
+func ExampleToValidUTF8() {
+       fmt.Printf("%s\n", strings.ToValidUTF8("abc", "\uFFFD"))
+       fmt.Printf("%s\n", strings.ToValidUTF8("a\xffb\xC0\xAFc\xff", ""))
+       fmt.Printf("%s\n", strings.ToValidUTF8("\xed\xa0\x80", "abc"))
+       // Output:
+       // abc
+       // abc
+       // abc
+}