b, ok := rd.(*Reader)
	if ok && len(b.buf) >= size {
		return b
	}
	r := new(Reader)
	r.reset(make([]byte, max(size, minReadBufferSize)), rd)
	return r
}

// NewReader returns a new [Reader] whose buffer has the default size.
func NewReader(rd io.Reader) *Reader {
	return NewReaderSize(rd, defaultBufSize)
}

// Size returns the size of the underlying buffer in bytes.
func (b *Reader) Size() int { return len(b.buf) }

			"A",
			"B(THIS)",
		),
		"x.\n",
	},
	*/
}

func TestLex(t *testing.T) {
	for _, test := range lexTests {
		input := NewInput(test.name)
		input.Push(NewTokenizer(test.name, strings.NewReader(test.input), nil))
		result := drain(input)
		if result != test.output {
			t.Errorf("%s: got %q expected %q", test.name, result, test.output)
		}
	}
}

	tokens []Token  // Body of macro.
}

// Tokenize turns a string into a list of Tokens; used to parse the -D flag and in tests.
func Tokenize(str string) []Token {
	t := NewTokenizer("command line", strings.NewReader(str), nil)
	var tokens []Token
	for {
		tok := t.Next()
		if tok == scanner.EOF {
			break
		}
		tokens = append(tokens, Make(tok, t.Text()))
	}
	return tokens

	}
	if _, err := tw.Write(data); err != nil {
		t.Fatalf("tw.Write: %v", err)
	}
	if err := tw.Close(); err != nil {
		t.Fatalf("tw.Close: %v", err)
	}

	// Read it back.
	tr := NewReader(&b)
	rHdr, err := tr.Next()
	if err != nil {
		t.Fatalf("tr.Next: %v", err)
	}
	if !reflect.DeepEqual(rHdr, hdr) {
		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
	}

	// ensure that this error is sticky.
	err error
}

type fileReader interface {
	io.Reader
	fileState

	WriteTo(io.Writer) (int64, error)
}

// NewReader creates a new [Reader] reading from r.
func NewReader(r io.Reader) *Reader {
	return &Reader{r: r, curr: &regFileReader{r, 0}}
}

// Next advances to the next entry in the tar archive.

}

// Parse an xml encoded plist. Plist values are mapped to string.
func parsePlistDict(dict []byte) (map[string]string, error) {
	d := xml.NewDecoder(bytes.NewReader(dict))
	values := make(map[string]string)
	var key string
	var hasKey bool
	for {
		tok, err := d.Token()
		if err == io.EOF {
			break
		}
		if err != nil {
			return nil, err
		}

pkg archive/tar, const TypeRegA ideal-char
pkg archive/tar, const TypeSymlink ideal-char
pkg archive/tar, const TypeXGlobalHeader ideal-char
pkg archive/tar, const TypeXHeader ideal-char
pkg archive/tar, func NewReader(io.Reader) *Reader
pkg archive/tar, func NewWriter(io.Writer) *Writer
pkg archive/tar, method (*Reader) Next() (*Header, error)
pkg archive/tar, method (*Reader) Read([]uint8) (int, error)

			log.Fatalf("loading imports: %v\n%s", err, out)
		}

		var stdPackages []string
		importMap := make(map[string]map[string]string)
		importDir := make(map[string]string)
		dec := json.NewDecoder(bytes.NewReader(out))
		for {
			var pkg struct {
				ImportPath, Dir string
				ImportMap       map[string]string
				Standard        bool
			}
			err := dec.Decode(&pkg)
			if err == io.EOF {
				break
			}