token.SUB_ASSIGN:     token.SUB,
	token.MUL_ASSIGN:     token.MUL,
	token.QUO_ASSIGN:     token.QUO,
	token.REM_ASSIGN:     token.REM,
	token.AND_ASSIGN:     token.AND,
	token.OR_ASSIGN:      token.OR,
	token.XOR_ASSIGN:     token.XOR,
	token.SHL_ASSIGN:     token.SHL,
	token.SHR_ASSIGN:     token.SHR,
	token.AND_NOT_ASSIGN: token.AND_NOT,
}

func TestZeroTok(t *testing.T) {
	// zero value for token.Token must be token.ILLEGAL

	SHL     // <<
	SHR     // >>
	AND_NOT // &^

	ADD_ASSIGN // +=
	SUB_ASSIGN // -=
	MUL_ASSIGN // *=
	QUO_ASSIGN // /=
	REM_ASSIGN // %=

	AND_ASSIGN     // &=
	OR_ASSIGN      // |=
	XOR_ASSIGN     // ^=
	SHL_ASSIGN     // <<=
	SHR_ASSIGN     // >>=
	AND_NOT_ASSIGN // &^=

	LAND  // &&
	LOR   // ||
	ARROW // <-
	INC   // ++
	DEC   // --

	EQL    // ==
	LSS    // <
	GTR    // >

			} else {
				// division
				tok = s.switch2(token.QUO, token.QUO_ASSIGN)
			}
		case '%':
			tok = s.switch2(token.REM, token.REM_ASSIGN)
		case '^':
			tok = s.switch2(token.XOR, token.XOR_ASSIGN)
		case '<':
			if s.ch == '-' {
				s.next()
				tok = token.ARROW
			} else {
				tok = s.switch4(token.LSS, token.LEQ, '<', token.SHL, token.SHL_ASSIGN)
			}
		case '>':

	{token.MUL_ASSIGN, "*=", operator},
	{token.QUO_ASSIGN, "/=", operator},
	{token.REM_ASSIGN, "%=", operator},

	{token.AND_ASSIGN, "&=", operator},
	{token.OR_ASSIGN, "|=", operator},
	{token.XOR_ASSIGN, "^=", operator},
	{token.SHL_ASSIGN, "<<=", operator},
	{token.SHR_ASSIGN, ">>=", operator},
	{token.AND_NOT_ASSIGN, "&^=", operator},

	{token.LAND, "&&", operator},
	{token.LOR, "||", operator},

	switch p.tok {
	case
		token.DEFINE, token.ASSIGN, token.ADD_ASSIGN,
		token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN,
		token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN,
		token.XOR_ASSIGN, token.SHL_ASSIGN, token.SHR_ASSIGN, token.AND_NOT_ASSIGN:
		// assignment statement
		pos, tok := p.pos, p.tok
		p.next()
		y := p.parseRhsList()
		return &ast.AssignStmt{x, pos, tok, y}
	}

	switch p.tok {
	case
		token.DEFINE, token.ASSIGN, token.ADD_ASSIGN,
		token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN,
		token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN,
		token.XOR_ASSIGN, token.SHL_ASSIGN, token.SHR_ASSIGN, token.AND_NOT_ASSIGN:
		// assignment statement, possibly part of a range clause
		pos, tok := p.pos, p.tok
		p.next()
		var y []ast.Expr
		isRange := false

		{"SUB_ASSIGN", Const, 0},
		{"SWITCH", Const, 0},
		{"TILDE", Const, 18},
		{"TYPE", Const, 0},
		{"Token", Type, 0},
		{"UnaryPrec", Const, 0},
		{"VAR", Const, 0},
		{"XOR", Const, 0},
		{"XOR_ASSIGN", Const, 0},
	},
	"go/types": {
		{"(*Alias).Obj", Method, 22},
		{"(*Alias).String", Method, 22},
		{"(*Alias).Underlying", Method, 22},
		{"(*ArgumentError).Error", Method, 18},

pkg go/token, const SWITCH Token
pkg go/token, const TYPE Token
pkg go/token, const UnaryPrec ideal-int
pkg go/token, const VAR Token
pkg go/token, const XOR Token
pkg go/token, const XOR_ASSIGN Token
pkg go/token, func Lookup(string) Token
pkg go/token, func NewFileSet() *FileSet
pkg go/token, method (*File) AddLine(int)
pkg go/token, method (*File) AddLineInfo(int, string, int)

pkg go/token, const SUB_ASSIGN = 24
pkg go/token, const SWITCH = 83
pkg go/token, const TYPE = 84
pkg go/token, const UnaryPrec = 6
pkg go/token, const VAR = 85
pkg go/token, const XOR = 19
pkg go/token, const XOR_ASSIGN = 30
pkg hash/adler32, const Size = 4
pkg hash/crc32, const Castagnoli = 2197175160
pkg hash/crc32, const IEEE = 3988292384
pkg hash/crc32, const Koopman = 3945912366
pkg hash/crc32, const Size = 4