}
	}
	return -1
}

// invokeMacro pushes onto the input Stack a Slice that holds the macro definition with the actual
// parameters substituted for the formals.
// Invoking a macro does not touch the PC/line history.
func (in *Input) invokeMacro(macro *Macro) {
	// If the macro has no arguments, just substitute the text.
	if macro.args == nil {
		in.Push(NewSlice(in.Base(), in.Line(), macro.tokens))
		return
	}