// A Reader implements the io.Reader, io.ReaderAt, io.WriterTo, io.Seeker,
// io.ByteScanner, and io.RuneScanner interfaces by reading from
// a byte slice.
// Unlike a [Buffer], a Reader is read-only and supports seeking.
// The zero value for Reader operates like a Reader of an empty slice.
type Reader struct {
	s        []byte
	i        int64 // current reading index
	prevRune int   // index of previous rune; or < 0
}

	// end of the token. It's where you are now, and you just read this token.
	if tok == '(' && in.Stack.Col() == prevCol+1 {
		// Macro has arguments. Scan list of formals.
		acceptArg := true
		args = []string{} // Zero length but not nil.
	Loop:
		for {
			tok = in.Stack.Next()
			switch tok {
			case ')':
				tok = in.Stack.Next() // First token of macro definition.
				break Loop
			case ',':
				if acceptArg {

			}
			divisor := p.factor()
			if divisor == 0 {
				p.errorf("division by zero")
			} else {
				value /= divisor
			}
		case '%':
			p.next()
			divisor := p.factor()
			if int64(value) < 0 {
				p.errorf("modulo of value with high bit set")
			}
			if divisor == 0 {
				p.errorf("modulo by zero")
			} else {
				value %= divisor
			}
		case lex.LSH:
			p.next()

// The count determines the number of subslices to return:
//
//	n > 0: at most n subslices; the last subslice will be the unsplit remainder.
//	n == 0: the result is nil (zero subslices)
//	n < 0: all subslices
//
// To split around the first instance of a separator, see Cut.
func SplitN(s, sep []byte, n int) [][]byte { return genSplit(s, sep, 0, n) }

pkg syscall (darwin-386), const IPV6_FW_DEL = 31
pkg syscall (darwin-386), const IPV6_FW_FLUSH = 32
pkg syscall (darwin-386), const IPV6_FW_GET = 34
pkg syscall (darwin-386), const IPV6_FW_ZERO = 33
pkg syscall (darwin-386), const IPV6_HLIMDEC = 1
pkg syscall (darwin-386), const IPV6_IPSEC_POLICY = 28
pkg syscall (darwin-386), const IPV6_JOIN_GROUP = 12
pkg syscall (darwin-386), const IPV6_LEAVE_GROUP = 13

	NOP	F2

	//	LNOP imm
	//	{
	//		outcode(int($1), &$2, 0, &nullgen);
	//	}
	NOP	$4

	//
	// special
	//
	SYSCALL
	BREAK
	SYNC

	//
	// conditional move on zero/nonzero gp value
	//
	CMOVN	R1, R2, R3
	CMOVZ	R1, R2, R3

	//
	// conditional move on fp false/true
	//
	CMOVF	R1, R2
	CMOVT	R1, R2

	//
	// conditional traps
	//
	TEQ	$1, R1, R2

		offset:     uint64(w.cw.count),
	}

	if strings.HasSuffix(fh.Name, "/") {
		// Set the compression method to Store to ensure data length is truly zero,
		// which the writeHeader method always encodes for the size fields.
		// This is necessary as most compression formats have non-zero lengths
		// even when compressing an empty string.
		fh.Method = Store
		fh.Flags &^= 0x8 // we will not write a data descriptor

introduce a Go variable that points at the C variable (the linker can
be told to initialize this pointer).  For example, if the gmp library
provided

	mpz_t zero;

then cgo would rewrite a reference to C.zero by introducing

	var _C_zero *C.mpz_t

and then replacing all instances of C.zero with (*_C_zero).

Cgo's most interesting translation is for functions.  If xxx is a C
function, then cgo rewrites C.xxx into a new function _C_xxx that

	line   int
	pos    int
}

func NewSlice(base *src.PosBase, line int, tokens []Token) *Slice {
	return &Slice{
		tokens: tokens,
		base:   base,
		line:   line,
		pos:    -1, // Next will advance to zero.
	}
}

func (s *Slice) Next() ScanToken {
	s.pos++
	if s.pos >= len(s.tokens) {
		return scanner.EOF
	}
	return s.tokens[s.pos].ScanToken
}

func (s *Slice) Text() string {

func (b *Reader) Size() int { return len(b.buf) }

// Reset discards any buffered data, resets all state, and switches
// the buffered reader to read from r.
// Calling Reset on the zero value of [Reader] initializes the internal buffer
// to the default size.
// Calling b.Reset(b) (that is, resetting a [Reader] to itself) does nothing.
func (b *Reader) Reset(r io.Reader) {