[This has nothing to do with the parser grammar I'm working on. This is fantasy...]

Quite aside from the ambiguity of problems of apostrophes, the difficulty of writing curved single quotes has been mentioned. Here's how a totally different, unrelated wiki program could work:

//italics// **bold** ' - straight apostrophe 'single quotes'' '''backwards single quotes'''

In other words, ' is rendered like the current apostrophe, and '' is a curved apostrophe that leans either way depending on what text is immediately adjacent. And for those cases where you want the quotes to lean the *other* way, ''' just does the opposite of whatever '' does.

I wonder if there'd be the same problems:

* I said: '''''twas the last thing we needed!'' (seems reasonable?

The good news at least '' and ''' always render as exactly one character, and no matter what you do in one part of a paragraph, it would never affect anything else.

Of course, there's no easy way to write combinations of straight and curved apostrophes, but that seems like a less likely situation than apostrophes and bold or italics.

I guess an alternative could use the "backquote":

``Single quotes'' I said: ``''twas the last thing we needed'!''

Yay, unambiguous.

Steve