example_test.go

package strcase_test

import (
	"fmt"
	"sort"
	"unicode/utf8"

	"github.com/charlievieth/strcase"
)

// // Index returns the index of the first instance of substr in s,
// // or -1 if substr is not present in s.
// // If ignoreCase is true the match is case-insensitive.
// func Index(s, substr string, ignoreCase bool) int {
// 	if ignoreCase {
// 		return strcase.Index(s, substr)
// 	}
// 	return strings.Index(s, substr)
// }

func ExampleCompare() {
	// ASCII
	fmt.Println(strcase.Compare("A", "b"))
	fmt.Println(strcase.Compare("A", "a"))
	fmt.Println(strcase.Compare("B", "a"))

	// Unicode
	fmt.Println(strcase.Compare("s", "ſ"))
	fmt.Println(strcase.Compare("αβδ", "ΑΒΔ"))

	// All invalid UTF-8 sequences are considered equal
	fmt.Println(strcase.Compare("\xff", string(utf8.RuneError)))
	// Output:
	// -1
	// 0
	// 1
	// 0
	// 0
	// 0
}

// Case insensitive sort using [strcase.Compare].
func ExampleCompare_sort() {
	a := []string{
		"b",
		"a",
		"α",
		"B",
		"Α", // U+0391
		"A",
	}
	sort.SliceStable(a, func(i, j int) bool {
		return strcase.Compare(a[i], a[j]) < 0
	})
	fmt.Printf("%q\n", a)
	// Output:
	// ["a" "A" "b" "B" "α" "Α"]
}

// Case insensitive search using [strcase.Compare].
func ExampleCompare_search() {
	a := []string{
		"a",
		"b",
		"α",
	}
	s := "B" // string being searched for
	i := sort.Search(len(a), func(i int) bool {
		return strcase.Compare(a[i], s) >= 0
	})

	fmt.Printf("%d: %q\n", i, a[i])
	// Output:
	// 1: "b"
}

// Using [strcase.Compare] and [sort.Find] to search a string slice.
func ExampleCompare_find() {
	a := []string{
		"a",
		"b",
		"α",
	}
	for _, s := range []string{"A", "B", "Z"} {
		i, found := sort.Find(len(a), func(i int) int {
			return strcase.Compare(s, a[i])
		})
		if found {
			fmt.Printf("%q found at index %d\n", s, i)
		} else {
			fmt.Printf("%q not found", s)
		}
	}
	// Output:
	// "A" found at index 0
	// "B" found at index 1
	// "Z" not found
}

func ExampleContains() {
	fmt.Println(strcase.Contains("SeaFood", "foo"))
	fmt.Println(strcase.Contains("SeaFood", "bar"))
	fmt.Println(strcase.Contains("SeaFood", ""))
	fmt.Println(strcase.Contains("", ""))
	fmt.Println(strcase.Contains("ΑΔΕΛΦΟΣΎΝΗΣ", "αδελφοσύνης"))

	// All invalid UTF-8 sequences are considered equal
	fmt.Println(strcase.Contains("\xed\xa0\x80\x80", "\xed\xbf\xbf\x80"))
	// Output:
	// true
	// false
	// true
	// true
	// true
	// true
}

func ExampleContains_invalid() {
	// All invalid UTF-8 sequences are considered equal
	fmt.Println(strcase.Contains("a\xff", string(utf8.RuneError)))
	fmt.Println(strcase.Contains("abc\xed\xa0\x80\x80", "\xed\xbf\xbf\x80"))
	// Output:
	// true
	// true
}

func ExampleContainsAny() {
	fmt.Println(strcase.ContainsAny("team", "I"))
	fmt.Println(strcase.ContainsAny("fail", "UI"))
	fmt.Println(strcase.ContainsAny("ure", "UI"))
	fmt.Println(strcase.ContainsAny("failure", "UI"))
	fmt.Println(strcase.ContainsAny("foo", ""))
	fmt.Println(strcase.ContainsAny("", ""))
	fmt.Println(strcase.ContainsAny("αβδ", "Α"))
	// Output:
	// false
	// true
	// true
	// true
	// false
	// false
	// true
}

func ExampleContainsRune() {
	// Finds whether a string contains a particular Unicode code point.
	fmt.Println(strcase.ContainsRune("aardvark", 'A'))
	fmt.Println(strcase.ContainsRune("timeout", 'A'))
	// Output:
	// true
	// false
}

func ExampleCount() {
	fmt.Println(strcase.Count("cheese", "e"))
	fmt.Println(strcase.Count("five", ""))
	fmt.Println(strcase.Count("ΑΒΔ", "α"))
	fmt.Println(strcase.Count("ΑΒΔ", ""))
	// Output:
	// 3
	// 5
	// 1
	// 4
}

func ExampleHasPrefix() {
	fmt.Println(strcase.HasPrefix("Gopher", "go"))
	fmt.Println(strcase.HasPrefix("Gopher", "c"))
	fmt.Println(strcase.HasPrefix("Gopher", ""))
	// Moonlight Night (Mayakovsky) - 1916
	fmt.Println(strcase.HasPrefix("А вот и полная повисла в воздухе.", "А ВОТ"))
	// Output:
	// true
	// false
	// true
	// true
}

func ExampleHasSuffix() {
	fmt.Println(strcase.HasSuffix("Amigo", "GO"))
	fmt.Println(strcase.HasSuffix("Amigo", "AMI"))
	fmt.Println(strcase.HasSuffix("Amigo", ""))
	// Moonlight Night (Mayakovsky) - 1916
	fmt.Println(strcase.HasSuffix("А вот и полная повисла в воздухе.", "В Воздухе."))
	// Output:
	// true
	// false
	// true
	// true
}

func ExampleIndex() {
	fmt.Println(strcase.Index("chicken", "KEN"))
	fmt.Println(strcase.Index("chicken", "DMR"))
	fmt.Println(strcase.Index("日a本b語ç日ð本ê語", "Ç日Ð本Ê"))

	// Output:
	// 4
	// -1
	// 11
}

func ExampleIndex_invalid() {
	// All invalid UTF-8 sequences are considered equal
	fmt.Println(strcase.Index("a\xff", string(utf8.RuneError)))
	fmt.Println(strcase.Index("abc\xed\xa0\x80\x80", "\xed\xbf\xbf\x80"))
	// Output:
	// 1
	// 3
}

func ExampleIndexAny() {
	fmt.Println(strcase.IndexAny("chicken", "AEIOUY"))
	fmt.Println(strcase.IndexAny("crwth", "AEIOUY"))
	// Kelvin K (U+212A) matches ASCII 'K' and 'k'
	fmt.Println(strcase.IndexAny("45K", "k"))
	// Latin small letter long S 'ſ' matches ASCII 'S' and 's'
	fmt.Println(strcase.IndexAny("salsa", "ſ"))
	// Output:
	// 2
	// -1
	// 2
	// 0
}

func ExampleIndexByte() {
	fmt.Println(strcase.IndexByte("golang", 'G'))
	fmt.Println(strcase.IndexByte("gophers", 'H'))
	fmt.Println(strcase.IndexByte("golang", 'X'))
	// Latin small letter long S 'ſ' matches ASCII 'S' and 's'
	fmt.Println(strcase.IndexByte("ſinfulneſs", 's'))
	// K
	// Output:
	// 0
	// 3
	// -1
	// 0
}

func ExampleIndexRune() {
	fmt.Println(strcase.IndexRune("chicken", 'K'))
	// U+212A is the code point for Kelvin K
	fmt.Println(strcase.IndexRune("chicken", '\u212A'))
	fmt.Println(strcase.IndexRune("chicken", 'D'))
	fmt.Println(strcase.IndexRune("日a本b語ç日", 'Ç'))
	// Output:
	// 4
	// 4
	// -1
	// 11
}

func ExampleLastIndex() {
	fmt.Println(strcase.Index("go gopher", "GO"))
	fmt.Println(strcase.LastIndex("go gopher", "GO"))
	fmt.Println(strcase.LastIndex("go gopher", "rodent"))
	// Moonlight Night (Mayakovsky) - 1916
	fmt.Println(strcase.LastIndex("А вот и полная повисла в воздухе.", "ПОЛНАЯ"))
	// Output:
	// 0
	// 3
	// -1
	// 13
}

func ExampleLastIndexAny() {
	fmt.Println(strcase.LastIndexAny("go gopher", "GO"))
	fmt.Println(strcase.LastIndexAny("go gopher", "RODENT"))
	fmt.Println(strcase.LastIndexAny("go gopher", "FAIL"))
	fmt.Println(strcase.LastIndexAny("Картѣ", "РТ" /* U+0420 & U+0422 */))
	// Output:
	// 4
	// 8
	// -1
	// 6
}

func ExampleLastIndexByte() {
	fmt.Println(strcase.LastIndexByte("Hello, world", 'L'))
	fmt.Println(strcase.LastIndexByte("Hello, world", 'O'))
	// Kelvin K (U+212A) matches ASCII 'K' and 'k'
	fmt.Println(strcase.LastIndexByte("Hello, \u212Aelvin", 'k'))
	// Output:
	// 10
	// 8
	// 7
}

func ExampleEqualFold() {
	fmt.Println(strcase.EqualFold("Go", "go"))
	// true because comparison uses simple case-folding
	fmt.Println(strcase.EqualFold("AB", "ab"))
	// false because comparison does not use full case-folding
	fmt.Println(strcase.EqualFold("ß", "ss"))
	// Output:
	// true
	// true
	// false
}

func ExampleTrimPrefix() {
	var s = "¡¡¡Hello, Gophers!!!"
	s = strcase.TrimPrefix(s, "¡¡¡HELLO, ")
	s = strcase.TrimPrefix(s, "¡¡¡HOWDY, ")
	fmt.Println(s)

	// All invalid code points are considered equal. Therefore the
	// behavior of TrimPrefix is unpredictable if the string contains
	// invalid UTF-8-encoded runes.
	//
	// This also applies to TrimSuffix, Cut, CutPrefix, and CutSuffix.
	fmt.Println(strcase.TrimPrefix("\xed\xa0\x80\x80foo", "\xed\xbf\xbf\x80"))
	// Output:
	// Gophers!!!
	// foo
}

func ExampleCut() {
	show := func(s, sep string) {
		before, after, found := strcase.Cut(s, 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")
	show("123 αβδ 456", "ΑΒΔ")
	// Output:
	// Cut("Gopher", "GO") = "", "pher", true
	// Cut("Gopher", "Ph") = "Go", "er", true
	// Cut("Gopher", "Er") = "Goph", "", true
	// Cut("Gopher", "Badger") = "Gopher", "", false
	// Cut("123 αβδ 456", "ΑΒΔ") = "123 ", " 456", true
}

func ExampleCutPrefix() {
	show := func(s, sep string) {
		after, found := strcase.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 := strcase.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 ExampleIndexNonASCII() {
	fmt.Println(strcase.IndexNonASCII("日a本b語ç日"))
	fmt.Println(strcase.IndexNonASCII("abc語"))
	fmt.Println(strcase.IndexNonASCII("abc"))
	// Output:
	// 0
	// 3
	// -1
}

func ExampleContainsNonASCII() {
	fmt.Println(strcase.ContainsNonASCII("日a本b語ç日"))
	fmt.Println(strcase.ContainsNonASCII("abc語"))
	fmt.Println(strcase.ContainsNonASCII("abc"))
	// Output:
	// true
	// true
	// false
}