// see the space itself. Note that text/scanner reports the position at the
	// 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 ')':