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.

				first = false
			} else {
				ranges[i].last = r - 1
				i++
				first = true
			}
		}
	}

	return len(ranges)
}

type singleRange struct {
	first rune
	last  rune

	"strings"
	"text/scanner"

	"cmd/internal/src"
)

// A ScanToken represents an input item. It is a simple wrapping of rune, as
// returned by text/scanner.Scanner, plus a couple of extra values.
type ScanToken rune

const (
	// Asm defines some two-character lexemes. We make up
	// a rune/ScanToken value for them - ugly but simple.
	LSH          ScanToken = -1000 - iota // << Left shift.

The [RuneLen] function returns the number of 16-bit words in
the UTF-16 encoding of the rune. It returns -1 if the rune

		}
		// Handle multi-byte Unicode.
		r, n := utf8.DecodeRune(in[i:])
		out = utf8.AppendRune(out, foldRune(r))
		i += n
	}
	return out
}

// foldRune is returns the smallest rune for all runes in the same fold set.
func foldRune(r rune) rune {
	for {
		r2 := unicode.SimpleFold(r)
		if r2 <= r {
			return r2
		}
		r = r2
	}