}

// An EmptyOp specifies a kind or mixture of zero-width assertions.
type EmptyOp uint8

const (
	EmptyBeginLine EmptyOp = 1 << iota
	EmptyEndLine
	EmptyBeginText
	EmptyEndText
	EmptyWordBoundary
	EmptyNoWordBoundary
)

// EmptyOpContext returns the zero-width assertions
// satisfied at the position between the runes r1 and r2.
// Passing r1 == -1 indicates that the position is

		if r2 >= 0 {
			return false
		}
		op &^= syntax.EmptyEndText
	}
	if op == 0 {
		return true
	}
	if syntax.IsWordChar(r1) != syntax.IsWordChar(r2) {
		op &^= syntax.EmptyWordBoundary
	} else {
		op &^= syntax.EmptyNoWordBoundary
	}
	return op == 0
}

// match runs the machine over the input starting at pos.
// It reports whether a match was found.

		{"EmptyBeginText", Const, 0},
		{"EmptyEndLine", Const, 0},
		{"EmptyEndText", Const, 0},
		{"EmptyNoWordBoundary", Const, 0},
		{"EmptyOp", Type, 0},
		{"EmptyOpContext", Func, 0},
		{"EmptyWordBoundary", Const, 0},
		{"ErrInternalError", Const, 0},
		{"ErrInvalidCharClass", Const, 0},
		{"ErrInvalidCharRange", Const, 0},
		{"ErrInvalidEscape", Const, 0},
		{"ErrInvalidNamedCapture", Const, 0},

pkg regexp/syntax, const EmptyBeginText = 4
pkg regexp/syntax, const EmptyEndLine = 2
pkg regexp/syntax, const EmptyEndText = 8
pkg regexp/syntax, const EmptyNoWordBoundary = 32
pkg regexp/syntax, const EmptyWordBoundary = 16
pkg regexp/syntax, const ErrInternalError = "regexp/syntax: internal error"
pkg regexp/syntax, const ErrInvalidCharClass = "invalid character class"