Make parameter expansion scheme great again

[x80486]

There is nothing wrong using | for separating substitutions/replacements. Nevertheless, I though I would give it a whirl because using the form :- is something that probably everyone in the "development world" is familiar with, and while I don't fully understand if it's more difficult to implement or not, it gives some other flexibility.

Would you consider adding or replacing | for (the well known) :- form?

[inhere]

:( This will not be changed for the time being because it is not compatible with older versions.