> A lot of very old indenters will treat tabs and spaces as interchangeable, …. Indeed. If you're going to align expressions in a file that uses tabs for inden

> A lot of very old indenters will treat tabs and spaces as interchangeable, …. Indeed. If you're going to align expressions in a file that uses tabs for indentation then you need to use tabs up to the block indentation level, but spaces after that for the alignment. That's the only way to ensure that the lines continue to be aligned for any tab-stop setting. Many editors will mangle this horribly, however, by replacing some or all of the spaces with tabs. If you're using tabs for indentation then you really need to turn on visible whitespace and also disable automatic conversion of spaces to tabs unless you're sure your editor is one of the few that gets it right.