maps: add examples for Clone,Copy and Equal

Change-Id: I72adaf48588e7d6cffbc0ee8005decda06808e84
Reviewed-on: https://go-review.googlesource.com/c/go/+/534055
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: shuang cui <imcusg@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

diff --git a/src/maps/example_test.go b/src/maps/example_test.go
index 779c66dcefde5c2e4c39ad52deb36763fbb08fe3..3d6b7d1ba09b6d66ca42964542c688c0f9ea62c8 100644 (file)
--- a/src/maps/example_test.go
+++ b/src/maps/example_test.go
@@ -10,6 +10,72 @@ import (
        "strings"
 )
 
+func ExampleClone() {
+       m1 := map[string]int{
+               "key": 1,
+       }
+       m2 := maps.Clone(m1)
+       m2["key"] = 100
+       fmt.Println(m1["key"])
+       fmt.Println(m2["key"])
+
+       m3 := map[string][]int{
+               "key": {1, 2, 3},
+       }
+       m4 := maps.Clone(m3)
+       fmt.Println(m4["key"][0])
+       m4["key"][0] = 100
+       fmt.Println(m3["key"][0])
+       fmt.Println(m4["key"][0])
+
+       // Output:
+       // 1
+       // 100
+       // 1
+       // 100
+       // 100
+}
+
+func ExampleCopy() {
+       m1 := map[string]int{
+               "one": 1,
+               "two": 2,
+       }
+       m2 := map[string]int{
+               "one": 10,
+       }
+
+       maps.Copy(m2, m1)
+       fmt.Println("m2 is:", m2)
+
+       m2["one"] = 100
+       fmt.Println("m1 is:", m1)
+       fmt.Println("m2 is:", m2)
+
+       m3 := map[string][]int{
+               "one": {1, 2, 3},
+               "two": {4, 5, 6},
+       }
+       m4 := map[string][]int{
+               "one": {7, 8, 9},
+       }
+
+       maps.Copy(m4, m3)
+       fmt.Println("m4 is:", m4)
+
+       m4["one"][0] = 100
+       fmt.Println("m3 is:", m3)
+       fmt.Println("m4 is:", m4)
+
+       // Output:
+       // m2 is: map[one:1 two:2]
+       // m1 is: map[one:1 two:2]
+       // m2 is: map[one:100 two:2]
+       // m4 is: map[one:[1 2 3] two:[4 5 6]]
+       // m3 is: map[one:[100 2 3] two:[4 5 6]]
+       // m4 is: map[one:[100 2 3] two:[4 5 6]]
+}
+
 func ExampleDeleteFunc() {
        m := map[string]int{
                "one":   1,
@@ -25,6 +91,30 @@ func ExampleDeleteFunc() {
        // map[four:4 two:2]
 }
 
+func ExampleEqual() {
+       m1 := map[int]string{
+               1:    "one",
+               10:   "Ten",
+               1000: "THOUSAND",
+       }
+       m2 := map[int]string{
+               1:    "one",
+               10:   "Ten",
+               1000: "THOUSAND",
+       }
+       m3 := map[int]string{
+               1:    "one",
+               10:   "ten",
+               1000: "thousand",
+       }
+
+       fmt.Println(maps.Equal(m1, m2))
+       fmt.Println(maps.Equal(m1, m3))
+       // Output:
+       // true
+       // false
+}
+
 func ExampleEqualFunc() {
        m1 := map[int]string{
                1:    "one",