}
		si += size1
	}
	j--
	for si = len(s); si > 0; {
		r1, size1 := DecodeLastRune(b[0:si])
		r2, size2 := DecodeLastRuneInString(s[0:si])
		if size1 != size2 {
			t.Errorf("DecodeLastRune/DecodeLastRuneInString(%q, %d) size mismatch %d/%d", s, si, size1, size2)
			return
		}
		if r1 != index[j].r {
			t.Errorf("DecodeLastRune(%q, %d) = %#04x, want %#04x", s, si, r1, index[j].r)
			return
		}

// license that can be found in the LICENSE file.

package utf8_test

import (
	"fmt"
	"unicode/utf8"
)

func ExampleDecodeLastRune() {
	b := []byte("Hello, 世界")

	for len(b) > 0 {
		r, size := utf8.DecodeLastRune(b)
		fmt.Printf("%c %v\n", r, size)

		b = b[:len(b)-size]
	}
	// Output:
	// 界 3
	// 世 3
	//   1
	// , 1
	// o 1
	// l 1
	// l 1
	// e 1
	// H 1
}

	}
	s3 := s[3]
	if s3 < locb || hicb < s3 {
		return RuneError, 1
	}
	return rune(s0&mask4)<<18 | rune(s1&maskx)<<12 | rune(s2&maskx)<<6 | rune(s3&maskx), 4
}

// DecodeLastRune unpacks the last UTF-8 encoding in p and returns the rune and
// its width in bytes. If p is empty it returns ([RuneError], 0). Otherwise, if
// the encoding is invalid, it returns (RuneError, 1). Both are impossible

// case-insensitively matches the lower-case kw.
func endsWithCSSKeyword(b []byte, kw string) bool {
	i := len(b) - len(kw)
	if i < 0 {
		// Too short.
		return false
	}
	if i != 0 {
		r, _ := utf8.DecodeLastRune(b[:i])
		if isCSSNmchar(r) {
			// Too long.
			return false
		}
	}
	// Many CSS keywords, such as "!important" can have characters encoded,
	// but the URI production does not allow that according to

	if len(b) == 0 {
		// In, `x=y/{{.}}*z` a json.Marshaler that produces "" should
		// not cause the output `x=y/*z`.
		return " null "
	}
	first, _ := utf8.DecodeRune(b)
	last, _ := utf8.DecodeLastRune(b)
	var buf strings.Builder
	// Prevent IdentifierNames and NumericLiterals from running into
	// keywords: in, instanceof, typeof, void
	pad := isJSIdentPart(first) || isJSIdentPart(last)
	if pad {

	r1, r2 := endOfText, endOfText
	// 0 < pos && pos <= len(i.str)
	if uint(pos-1) < uint(len(i.str)) {
		r1 = rune(i.str[pos-1])
		if r1 >= utf8.RuneSelf {
			r1, _ = utf8.DecodeLastRune(i.str[:pos])
		}
	}
	// 0 <= pos && pos < len(i.str)
	if uint(pos) < uint(len(i.str)) {
		r2 = rune(i.str[pos])
		if r2 >= utf8.RuneSelf {
			r2, _ = utf8.DecodeRune(i.str[pos:])
		}
	}

		{"Decode", Func, 0},
		{"DecodeRune", Func, 0},
		{"Encode", Func, 0},
		{"EncodeRune", Func, 0},
		{"IsSurrogate", Func, 0},
	},
	"unicode/utf8": {
		{"AppendRune", Func, 18},
		{"DecodeLastRune", Func, 0},
		{"DecodeLastRuneInString", Func, 0},
		{"DecodeRune", Func, 0},
		{"DecodeRuneInString", Func, 0},
		{"EncodeRune", Func, 0},
		{"FullRune", Func, 0},
		{"FullRuneInString", Func, 0},

pkg unicode/utf8, const MaxRune ideal-char
pkg unicode/utf8, const RuneError ideal-char
pkg unicode/utf8, const RuneSelf ideal-int
pkg unicode/utf8, const UTFMax ideal-int
pkg unicode/utf8, func DecodeLastRune([]uint8) (int32, int)
pkg unicode/utf8, func DecodeLastRuneInString(string) (int32, int)
pkg unicode/utf8, func DecodeRune([]uint8) (int32, int)
pkg unicode/utf8, func DecodeRuneInString(string) (int32, int)