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| author | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
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| committer | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
| commit | 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 (patch) | |
| tree | f1190704f78f04a2b0b4c977d20fe96a828377f1 /devdocs/go/maps%2Findex.html | |
new repository
Diffstat (limited to 'devdocs/go/maps%2Findex.html')
| -rw-r--r-- | devdocs/go/maps%2Findex.html | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/devdocs/go/maps%2Findex.html b/devdocs/go/maps%2Findex.html new file mode 100644 index 00000000..3d751a7d --- /dev/null +++ b/devdocs/go/maps%2Findex.html @@ -0,0 +1,126 @@ +<h1> Package maps </h1> <ul id="short-nav"> +<li><code>import "maps"</code></li> +<li><a href="#pkg-overview" class="overviewLink">Overview</a></li> +<li><a href="#pkg-index" class="indexLink">Index</a></li> +<li><a href="#pkg-examples" class="examplesLink">Examples</a></li> +</ul> <h2 id="pkg-overview">Overview </h2> <p>Package maps defines various functions useful with maps of any type. </p> <h2 id="pkg-index">Index </h2> <ul id="manual-nav"> +<li><a href="#Clone">func Clone[M ~map[K]V, K comparable, V any](m M) M</a></li> +<li><a href="#Copy">func Copy[M1 ~map[K]V, M2 ~map[K]V, K comparable, V any](dst M1, src M2)</a></li> +<li><a href="#DeleteFunc">func DeleteFunc[M ~map[K]V, K comparable, V any](m M, del func(K, V) bool)</a></li> +<li><a href="#Equal">func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool</a></li> +<li><a href="#EqualFunc">func EqualFunc[M1 ~map[K]V1, M2 ~map[K]V2, K comparable, V1, V2 any](m1 M1, m2 M2, eq func(V1, V2) bool) bool</a></li> +</ul> <div id="pkg-examples"> <h3>Examples</h3> <dl> <dd><a class="exampleLink" href="#example_Clone">Clone</a></dd> <dd><a class="exampleLink" href="#example_Copy">Copy</a></dd> <dd><a class="exampleLink" href="#example_DeleteFunc">DeleteFunc</a></dd> <dd><a class="exampleLink" href="#example_Equal">Equal</a></dd> <dd><a class="exampleLink" href="#example_EqualFunc">EqualFunc</a></dd> </dl> </div> <h3>Package files</h3> <p> <span>maps.go</span> </p> <h2 id="Clone">func <span>Clone</span> </h2> <pre data-language="go">func Clone[M ~map[K]V, K comparable, V any](m M) M</pre> <p>Clone returns a copy of m. This is a shallow clone: the new keys and values are set using ordinary assignment. </p> <h4 id="example_Clone"> <span class="text">Example</span> +</h4> <p>Code:</p> <pre class="code" data-language="go">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]) + +</pre> <p>Output:</p> <pre class="output" data-language="go">1 +100 +1 +100 +100 +</pre> <h2 id="Copy">func <span>Copy</span> </h2> <pre data-language="go">func Copy[M1 ~map[K]V, M2 ~map[K]V, K comparable, V any](dst M1, src M2)</pre> <p>Copy copies all key/value pairs in src adding them to dst. When a key in src is already present in dst, the value in dst will be overwritten by the value associated with the key in src. </p> <h4 id="example_Copy"> <span class="text">Example</span> +</h4> <p>Code:</p> <pre class="code" data-language="go">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) + +</pre> <p>Output:</p> <pre class="output" data-language="go">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]] +</pre> <h2 id="DeleteFunc">func <span>DeleteFunc</span> </h2> <pre data-language="go">func DeleteFunc[M ~map[K]V, K comparable, V any](m M, del func(K, V) bool)</pre> <p>DeleteFunc deletes any key/value pairs from m for which del returns true. </p> <h4 id="example_DeleteFunc"> <span class="text">Example</span> +</h4> <p>Code:</p> <pre class="code" data-language="go">m := map[string]int{ + "one": 1, + "two": 2, + "three": 3, + "four": 4, +} +maps.DeleteFunc(m, func(k string, v int) bool { + return v%2 != 0 // delete odd values +}) +fmt.Println(m) +</pre> <p>Output:</p> <pre class="output" data-language="go">map[four:4 two:2] +</pre> <h2 id="Equal">func <span>Equal</span> </h2> <pre data-language="go">func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool</pre> <p>Equal reports whether two maps contain the same key/value pairs. Values are compared using ==. </p> <h4 id="example_Equal"> <span class="text">Example</span> +</h4> <p>Code:</p> <pre class="code" data-language="go">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)) +</pre> <p>Output:</p> <pre class="output" data-language="go">true +false +</pre> <h2 id="EqualFunc">func <span>EqualFunc</span> </h2> <pre data-language="go">func EqualFunc[M1 ~map[K]V1, M2 ~map[K]V2, K comparable, V1, V2 any](m1 M1, m2 M2, eq func(V1, V2) bool) bool</pre> <p>EqualFunc is like Equal, but compares values using eq. Keys are still compared with ==. </p> <h4 id="example_EqualFunc"> <span class="text">Example</span> +</h4> <p>Code:</p> <pre class="code" data-language="go">m1 := map[int]string{ + 1: "one", + 10: "Ten", + 1000: "THOUSAND", +} +m2 := map[int][]byte{ + 1: []byte("One"), + 10: []byte("Ten"), + 1000: []byte("Thousand"), +} +eq := maps.EqualFunc(m1, m2, func(v1 string, v2 []byte) bool { + return strings.ToLower(v1) == strings.ToLower(string(v2)) +}) +fmt.Println(eq) +</pre> <p>Output:</p> <pre class="output" data-language="go">true +</pre><div class="_attribution"> + <p class="_attribution-p"> + © Google, Inc.<br>Licensed under the Creative Commons Attribution License 3.0.<br> + <a href="http://golang.org/pkg/maps/" class="_attribution-link">http://golang.org/pkg/maps/</a> + </p> +</div> |
