)

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' {

// written, not just their values. Particularly useful for runes.
func f8(r rune) {
	const x = 10
	switch r {
	case 33, 33: // ERROR "duplicate case (33 in switch)?"
	case 34, '"': // ERROR "duplicate case '"' .value 34. in switch"
	case 35, rune('#'): // ERROR "duplicate case (rune.'#'. .value 35. in switch)?"
	case 36, rune(36): // ERROR "duplicate case (rune.36. .value 36. in switch)?"

	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.

package mime

import (
	"strings"
)

// isTSpecial reports whether rune is in 'tspecials' as defined by RFC
// 1521 and RFC 2045.
func isTSpecial(r rune) bool {
	return strings.ContainsRune(`()<>@,;:\"/[]?=`, r)
}

// isTokenChar reports whether rune is in 'token' as defined by RFC
// 1521 and RFC 2045.
func isTokenChar(r rune) bool {
	// token := 1*<any (US-ASCII) CHAR except SPACE, CTLs,
	//             or tspecials>

				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
	}