// 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
}

func (s *Scanner) MaxTokenSize(n int) {
	if n < utf8.UTFMax || n > 1e9 {
		panic("bad max token size")
	}
	if n < len(s.buf) {
		s.buf = make([]byte, n)
	}
	s.maxTokenSize = n
}

// ErrOrEOF is like Err, but returns EOF. Used to test a corner case.
func (s *Scanner) ErrOrEOF() error {
	return s.err

	switch op {
	case ppc64.ACMP, ppc64.ACMPU, ppc64.ACMPW, ppc64.ACMPWU, ppc64.AFCMPU:
		return true
	}
	return false
}

// IsPPC64NEG reports whether the op (as defined by an ppc64.A* constant) is
// one of the NEG-like instructions that require special handling.
func IsPPC64NEG(op obj.As) bool {
	switch op {
	case ppc64.AADDMECC, ppc64.AADDMEVCC, ppc64.AADDMEV, ppc64.AADDME,
		ppc64.AADDZECC, ppc64.AADDZEVCC, ppc64.AADDZEV, ppc64.AADDZE,

}

// The other files in this directory each contain an implementation of TokenReader.

// A TokenReader is like a reader, but returns lex tokens of type Token. It also can tell you what
// the text of the most recently returned token is, and where it was found.
// The underlying scanner elides all spaces except newline, so the input looks like a stream of
// Tokens; original spacing is lost but we don't need it.
type TokenReader interface {

	switch op {
	case arm.ACMN, arm.ACMP, arm.ATEQ, arm.ATST:
		return true
	}
	return false
}

// IsARMSTREX reports whether the op (as defined by an arm.A* constant) is
// one of the STREX-like instructions that require special handling.
func IsARMSTREX(op obj.As) bool {
	switch op {
	case arm.ASTREX, arm.ASTREXD, arm.ASWPW, arm.ASWPBU:
		return true
	}
	return false
}

	base *src.PosBase
	line int
	file *os.File // If non-nil, file descriptor to close.
}

func NewTokenizer(name string, r io.Reader, file *os.File) *Tokenizer {
	var s scanner.Scanner
	s.Init(r)
	// Newline is like a semicolon; other space characters are fine.
	s.Whitespace = 1<<'\t' | 1<<'\r' | 1<<' '
	// Don't skip comments: we need to count newlines.
	s.Mode = scanner.ScanChars |
		scanner.ScanFloats |
		scanner.ScanIdents |

		// We should get a no exit code error
		if err == nil || !wantErr.MatchString(err.Error()) {
			t.Errorf("want error matching %s, got %s", wantErr, err)
		}
		// And it should flush all output (even if it looks
		// like we may be getting an exit code)
		if got := out.String(); text != got {
			t.Errorf("want full output %q, got %q", text, got)
		}
	}
	wantErr = regexp.MustCompile("^no exit code")
	check("abc")
	check("exitcode")

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

/*
An example of wrapping a C library in Go. This is the GNU
multiprecision library gmp's integer type mpz_t wrapped to look like
the Go package big's integer type Int.

This is a syntactically valid Go program—it can be parsed with the Go
parser and processed by godoc—but it is not compiled directly by gc.