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<h1> Package cmp </h1> <ul id="short-nav">
<li><code>import "cmp"</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 cmp provides types and functions related to comparing ordered values. </p> <h2 id="pkg-index">Index </h2> <ul id="manual-nav">
<li><a href="#Compare">func Compare[T Ordered](x, y T) int</a></li>
<li><a href="#Less">func Less[T Ordered](x, y T) bool</a></li>
<li><a href="#Or">func Or[T comparable](vals ...T) T</a></li>
<li><a href="#Ordered">type Ordered</a></li>
</ul> <div id="pkg-examples"> <h3>Examples</h3> <dl> <dd><a class="exampleLink" href="#example_Or">Or</a></dd> <dd><a class="exampleLink" href="#example_Or_sort">Or (Sort)</a></dd> </dl> </div> <h3>Package files</h3> <p> <span>cmp.go</span> </p> <h2 id="Compare">func <span>Compare</span> </h2> <pre data-language="go">func Compare[T Ordered](x, y T) int</pre> <p>Compare returns </p>
<pre data-language="go">-1 if x is less than y,
0 if x equals y,
+1 if x is greater than y.
</pre> <p>For floating-point types, a NaN is considered less than any non-NaN, a NaN is considered equal to a NaN, and -0.0 is equal to 0.0. </p>
<h2 id="Less">func <span>Less</span> </h2> <pre data-language="go">func Less[T Ordered](x, y T) bool</pre> <p>Less reports whether x is less than y. For floating-point types, a NaN is considered less than any non-NaN, and -0.0 is not less than (is equal to) 0.0. </p>
<h2 id="Or">func <span>Or</span> </h2> <pre data-language="go">func Or[T comparable](vals ...T) T</pre> <p>Or returns the first of its arguments that is not equal to the zero value. If no argument is non-zero, it returns the zero value. </p> <h4 id="example_Or"> <span class="text">Example</span>
</h4> <p>Code:</p> <pre class="code" data-language="go">// Suppose we have some user input
// that may or may not be an empty string
userInput1 := ""
userInput2 := "some text"
fmt.Println(cmp.Or(userInput1, "default"))
fmt.Println(cmp.Or(userInput2, "default"))
fmt.Println(cmp.Or(userInput1, userInput2, "default"))
</pre> <p>Output:</p> <pre class="output" data-language="go">default
some text
some text
</pre> <h4 id="example_Or_sort"> <span class="text">Example (Sort)</span>
</h4> <p>Code:</p> <pre class="code" data-language="go">type Order struct {
Product string
Customer string
Price float64
}
orders := []Order{
{"foo", "alice", 1.00},
{"bar", "bob", 3.00},
{"baz", "carol", 4.00},
{"foo", "alice", 2.00},
{"bar", "carol", 1.00},
{"foo", "bob", 4.00},
}
// Sort by customer first, product second, and last by higher price
slices.SortFunc(orders, func(a, b Order) int {
return cmp.Or(
cmp.Compare(a.Customer, b.Customer),
cmp.Compare(a.Product, b.Product),
cmp.Compare(b.Price, a.Price),
)
})
for _, order := range orders {
fmt.Printf("%s %s %.2f\n", order.Product, order.Customer, order.Price)
}
</pre> <p>Output:</p> <pre class="output" data-language="go">foo alice 2.00
foo alice 1.00
bar bob 3.00
foo bob 4.00
bar carol 1.00
baz carol 4.00
</pre> <h2 id="Ordered">type <span>Ordered</span> <span title="Added in Go 1.21">1.21</span> </h2> <p>Ordered is a constraint that permits any ordered type: any type that supports the operators < <= >= >. If future releases of Go add new ordered types, this constraint will be modified to include them. </p>
<p>Note that floating-point types may contain NaN ("not-a-number") values. An operator such as == or < will always report false when comparing a NaN value with any other value, NaN or not. See the <a href="#Compare">Compare</a> function for a consistent way to compare NaN values. </p>
<pre data-language="go">type Ordered interface {
~int | ~int8 | ~int16 | ~int32 | ~int64 |
~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
~float32 | ~float64 |
~string
}</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/cmp/" class="_attribution-link">http://golang.org/pkg/cmp/</a>
</p>
</div>
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