var _ = true == '\'' // ERROR "invalid operation: (cannot compare true)|(true) == '\\'' \(mismatched types untyped bool and untyped rune\)"

	r = '\x00'
	for i, r = range s {
		b[i] = byte(r)
	}
	if want := n - 1; i != want {
		fmt.Printf("index after range with side-effect = %d want %d\n", i, want)
		os.Exit(1)
	}
	if want := rune(n); r != want {
		fmt.Printf("rune after range with side-effect = %q want %q\n", r, want)
		os.Exit(1)
	}

	i = -1
	// i is shadowed here, so its value should be unchanged.
	for i := range s {
		b[i] = s[i]
	}

package main

import (
	"fmt"
	"os"
	"unicode/utf8"
)

func main() {
	s := "\000\123\x00\xca\xFE\u0123\ubabe\U0000babe\U0010FFFFx"
	expect := []rune{0, 0123, 0, 0xFFFD, 0xFFFD, 0x123, 0xbabe, 0xbabe, 0x10FFFF, 'x'}
	offset := 0
	var i int
	var c rune
	ok := true
	cnum := 0
	for i, c = range s {
		r, size := utf8.DecodeRuneInString(s[i:len(s)]) // check it another way
		if i != offset {

	c.inst(InstFail)
}

var anyRuneNotNL = []rune{0, '\n' - 1, '\n' + 1, unicode.MaxRune}
var anyRune = []rune{0, unicode.MaxRune}

func (c *compiler) compile(re *Regexp) frag {
	switch re.Op {
	case OpNoMatch:
		return c.fail()
	case OpEmptyMatch:
		return c.nop()
	case OpLiteral:
		if len(re.Rune) == 0 {
			return c.nop()
		}
		var f frag
		for j := range re.Rune {
			f1 := c.rune(re.Rune[j:j+1], re.Flags)

				c, name)
		}
	}
	if !isAlphaNumeric(rune(name[len(name)-1])) {
		return fmt.Errorf("invalid name %q, should end with a letter or digit", name)
	}
	return nil
}

func isLetter(c rune) bool {
	return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z')
}

func isDigit(c rune) bool {
	return '0' <= c && c <= '9'
}

func isAlphaNumeric(c rune) bool {
	return isLetter(c) || isDigit(c)

		}
	}
	return
}

func (s *Scanner) scanNumber(ch rune, seenDot bool) (rune, rune) {
	base := 10         // number base
	prefix := rune(0)  // one of 0 (decimal), '0' (0-octal), 'x', 'o', or 'b'
	digsep := 0        // bit 0: digit present, bit 1: '_' present
	invalid := rune(0) // invalid digit in literal, or 0

	// integer part
	var tok rune
	var ds int
	if !seenDot {
		tok = Int
		if ch == '0' {

)

var platformZoneSources []string // none on Plan 9

func isSpace(r rune) bool {
	return r == ' ' || r == '\t' || r == '\n'
}

// Copied from strings to avoid a dependency.
func fields(s string) []string {
	// First count the fields.
	n := 0
	inField := false
	for _, rune := range s {
		wasInField := inField
		inField = !isSpace(rune)
		if inField && !wasInField {
			n++
		}
	}

	// Now create them.

// Scanners may do rune-at-a-time scanning or ask the ScanState
// to discover the next space-delimited token.
type ScanState interface {
	// ReadRune reads the next rune (Unicode code point) from the input.
	// If invoked during Scanln, Fscanln, or Sscanln, ReadRune() will
	// return EOF after returning the first '\n' or when reading beyond
	// the specified width.
	ReadRune() (r rune, size int, err error)

	{"x \xc0\xc0 ", "x \xc0\xc0"},
	{"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
	{"x ☺ ", "x ☺"},
}

func tenRunes(ch rune) string {
	r := make([]rune, 10)
	for i := range r {
		r[i] = ch
	}
	return string(r)
}

// User-defined self-inverse mapping function
func rot13(r rune) rune {
	step := rune(13)
	if r >= 'a' && r <= 'z' {
		return ((r - 'a' + step) % 26) + 'a'
	}
	if r >= 'A' && r <= 'Z' {

	atEOF    bool

	pDst int // pDst points past the last written rune in dst.
	pSrc int // pSrc points to the start of the currently scanned rune.

	// checkpoints safe to return in Transform, where nDst <= pDst and nSrc <= pSrc.
	nDst, nSrc int
	err        error

	sz   int  // size of current rune
	info info // case information of currently scanned rune

	// State preserved across calls to Transform.