From db77255c8b86ff42c65a903eaf1f26c67749e6da Mon Sep 17 00:00:00 2001
From: Bhavitha <106284071+bhavi-koduru@users.noreply.github.com>
Date: Wed, 12 Apr 2023 11:58:42 -0700
Subject: [PATCH] add Cut method to bytes package
---
api/go1.16.txt | 1 +
src/bytes/bytes.go | 13 ++++
src/bytes/bytes_test.go | 23 +++++++
src/bytes/example_test.go | 138 +++++++++++++++++++-------------------
4 files changed, 107 insertions(+), 68 deletions(-)
diff --git a/api/go1.16.txt b/api/go1.16.txt
index ce015fd6fb..72f0a80981 100644
--- a/api/go1.16.txt
+++ b/api/go1.16.txt
@@ -1,5 +1,6 @@
pkg archive/zip, method (*ReadCloser) Open(string) (fs.File, error)
pkg archive/zip, method (*Reader) Open(string) (fs.File, error)
+pkg bytes, func Cut([]uint8, []uint8) ([]uint8, []uint8, bool)
pkg crypto/x509, method (SystemRootsError) Unwrap() error
pkg debug/elf, const DT_ADDRRNGHI = 1879047935
pkg debug/elf, const DT_ADDRRNGHI DynTag
diff --git a/src/bytes/bytes.go b/src/bytes/bytes.go
index ce52649f13..ec9a2eb693 100644
--- a/src/bytes/bytes.go
+++ b/src/bytes/bytes.go
@@ -1174,3 +1174,16 @@ func Index(s, sep []byte) int {
}
return -1
}
+
+// Cut slices s around the first instance of sep,
+// returning the text before and after sep.
+// The found result reports whether sep appears in s.
+// If sep does not appear in s, cut returns s, "", false.
+//
+// Cut returns slices of the original slice s, not copies.
+func Cut(s, sep []byte) (before, after []byte, found bool) {
+ if i := Index(s, sep); i >= 0 {
+ return s[:i], s[i+len(sep):], true
+ }
+ return s, nil, false
+}
diff --git a/src/bytes/bytes_test.go b/src/bytes/bytes_test.go
index 544ee46f90..538e613c8e 100644
--- a/src/bytes/bytes_test.go
+++ b/src/bytes/bytes_test.go
@@ -1565,6 +1565,29 @@ func TestEqualFold(t *testing.T) {
}
}
+var cutTests = []struct {
+ s, sep string
+ before, after string
+ found bool
+}{
+ {"abc", "b", "a", "c", true},
+ {"abc", "a", "", "bc", true},
+ {"abc", "c", "ab", "", true},
+ {"abc", "abc", "", "", true},
+ {"abc", "", "", "abc", true},
+ {"abc", "d", "abc", "", false},
+ {"", "d", "", "", false},
+ {"", "", "", "", true},
+}
+
+func TestCut(t *testing.T) {
+ for _, tt := range cutTests {
+ if before, after, found := Cut([]byte(tt.s), []byte(tt.sep)); string(before) != tt.before || string(after) != tt.after || found != tt.found {
+ t.Errorf("Cut(%q, %q) = %q, %q, %v, want %q, %q, %v", tt.s, tt.sep, before, after, found, tt.before, tt.after, tt.found)
+ }
+ }
+}
+
func TestBufferGrowNegative(t *testing.T) {
defer func() {
if err := recover(); err == nil {
diff --git a/src/bytes/example_test.go b/src/bytes/example_test.go
index ae93202b57..a1a6c2d292 100644
--- a/src/bytes/example_test.go
+++ b/src/bytes/example_test.go
@@ -92,36 +92,6 @@ func ExampleCompare_search() {
}
}
-func ExampleTrimSuffix() {
- var b = []byte("Hello, goodbye, etc!")
- b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
- b = bytes.TrimSuffix(b, []byte("gopher"))
- b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
- os.Stdout.Write(b)
- // Output: Hello, world!
-}
-
-func ExampleTrimPrefix() {
- var b = []byte("Goodbye,, world!")
- b = bytes.TrimPrefix(b, []byte("Goodbye,"))
- b = bytes.TrimPrefix(b, []byte("See ya,"))
- fmt.Printf("Hello%s", b)
- // Output: Hello, world!
-}
-
-func ExampleFields() {
- fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz ")))
- // Output: Fields are: ["foo" "bar" "baz"]
-}
-
-func ExampleFieldsFunc() {
- f := func(c rune) bool {
- return !unicode.IsLetter(c) && !unicode.IsNumber(c)
- }
- fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte(" foo1;bar2,baz3..."), f))
- // Output: Fields are: ["foo1" "bar2" "baz3"]
-}
-
func ExampleContains() {
fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
@@ -168,6 +138,22 @@ func ExampleCount() {
// 5
}
+func ExampleCut() {
+ show := func(s, sep string) {
+ before, after, found := bytes.Cut([]byte(s), []byte(sep))
+ fmt.Printf("Cut(%q, %q) = %q, %q, %v\n", s, sep, before, after, found)
+ }
+ show("Gopher", "Go")
+ show("Gopher", "ph")
+ show("Gopher", "er")
+ show("Gopher", "Badger")
+ // Output:
+ // Cut("Gopher", "Go") = "", "pher", true
+ // Cut("Gopher", "ph") = "Go", "er", true
+ // Cut("Gopher", "er") = "Goph", "", true
+ // Cut("Gopher", "Badger") = "Gopher", "", false
+}
+
func ExampleEqual() {
fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
@@ -181,6 +167,19 @@ func ExampleEqualFold() {
// Output: true
}
+func ExampleFields() {
+ fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz ")))
+ // Output: Fields are: ["foo" "bar" "baz"]
+}
+
+func ExampleFieldsFunc() {
+ f := func(c rune) bool {
+ return !unicode.IsLetter(c) && !unicode.IsNumber(c)
+ }
+ fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte(" foo1;bar2,baz3..."), f))
+ // Output: Fields are: ["foo1" "bar2" "baz3"]
+}
+
func ExampleHasPrefix() {
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
@@ -246,6 +245,12 @@ func ExampleIndexRune() {
// -1
}
+func ExampleJoin() {
+ s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
+ fmt.Printf("%s", bytes.Join(s, []byte(", ")))
+ // Output: foo, bar, baz
+}
+
func ExampleLastIndex() {
fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
@@ -286,10 +291,12 @@ func ExampleLastIndexFunc() {
// -1
}
-func ExampleJoin() {
- s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
- fmt.Printf("%s", bytes.Join(s, []byte(", ")))
- // Output: foo, bar, baz
+func ExampleReader_Len() {
+ fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
+ fmt.Println(bytes.NewReader([]byte("ã“ã‚“ã«ã¡ã¯!")).Len())
+ // Output:
+ // 3
+ // 16
}
func ExampleRepeat() {
@@ -399,20 +406,6 @@ func ExampleTrimFunc() {
// go-gopher!
}
-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", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
- // Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
-}
-
func ExampleTrimLeft() {
fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
// Output:
@@ -429,11 +422,28 @@ func ExampleTrimLeftFunc() {
// go-gopher!567
}
+func ExampleTrimPrefix() {
+ var b = []byte("Goodbye,, world!")
+ b = bytes.TrimPrefix(b, []byte("Goodbye,"))
+ b = bytes.TrimPrefix(b, []byte("See ya,"))
+ fmt.Printf("Hello%s", b)
+ // Output: Hello, world!
+}
+
func ExampleTrimSpace() {
fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
// Output: a lone gopher
}
+func ExampleTrimSuffix() {
+ var b = []byte("Hello, goodbye, etc!")
+ b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
+ b = bytes.TrimSuffix(b, []byte("gopher"))
+ b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
+ os.Stdout.Write(b)
+ // Output: Hello, world!
+}
+
func ExampleTrimRight() {
fmt.Print(string(bytes.TrimRight([]byte("453gopher8257"), "0123456789")))
// Output:
@@ -450,21 +460,6 @@ func ExampleTrimRightFunc() {
// 1234go-gopher!
}
-func ExampleToUpper() {
- fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
- // Output: GOPHER
-}
-
-func ExampleToUpperSpecial() {
- str := []byte("ahoj vývojári golang")
- totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
- fmt.Println("Original : " + string(str))
- fmt.Println("ToUpper : " + string(totitle))
- // Output:
- // Original : ahoj vývojári golang
- // ToUpper : AHOJ VÃVOJÃRÄ° GOLANG
-}
-
func ExampleToLower() {
fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
// Output: gopher
@@ -480,10 +475,17 @@ func ExampleToLowerSpecial() {
// ToLower : ahoj vývojári golang
}
-func ExampleReader_Len() {
- fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
- fmt.Println(bytes.NewReader([]byte("ã“ã‚“ã«ã¡ã¯!")).Len())
+func ExampleToUpper() {
+ fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
+ // Output: GOPHER
+}
+
+func ExampleToUpperSpecial() {
+ str := []byte("ahoj vývojári golang")
+ totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
+ fmt.Println("Original : " + string(str))
+ fmt.Println("ToUpper : " + string(totitle))
// Output:
- // 3
- // 16
+ // Original : ahoj vývojári golang
+ // ToUpper : AHOJ VÃVOJÃRÄ° GOLANG
}
--
2.39.1