It's not possible to unambiguously parse nested quotes, so to support
nesting, a new syntax would be needed. Maybe something xml-like?
+
+> You can, however, unambiguously parse nested square brackets, and I think
+> that would solve the problem, as long as you never allow the contents of a
+> directive to contain a *partial* directive, which seems reasonable to me.
+>
+> For example, I *think* you can unambiguously parse the following:
+>
+> \[[!if test="enabled(template) and templates/foo" then="""
+> [[!template id=foo content="""Flying Purple People Eater"""]]
+> """]]
+>
+> --[[JoshTriplett]]
+
+>> Yes it's definitely possible to do something like that. I'm not 100%
+>> sure if it can be done in perl regexp or needs a real recursive descent
+>> parser though.
+>>
+>> In the meantime, this is an interesting approach:
+>> <https://github.com/timo/ikiwiki/commit/a73837a8f26147e42a0bb2dde38b4890b27822b3>
+>>
+>> \[[!directive text=\<\<FOO
+>> ...
+>> FOO]]
+>>
+>> Since that's implemented, I will probably just merge it,
+>> once I satisfy myself it doesn't blow up in any edge cases.
+>> (It also adds triple single quotes as a third, distinct type of quotes,
+>> which feels a bit redundant given the here docs.) --[[Joey]]
+>>
+>> Hmm, that patch changes a `m///sgx` to a `m///msgx`. Meaning
+>> that any '^' or '$' inside the regexp will change behavior from matching
+>> the start/end of string to matching the start/end of individual lines
+>> within the string. And there is one legacy '$' which must then
+>> change behavior; the "delimiter to next param".
+>>
+>> So, I'm not sure what behavior that will cause, but I suspect it will
+>> be a bug. Unless the `\s+|$' already stops matching at a newline within
+>> the string like it's whitespace. That needs more alalysis.
+>>
+>> Also, the patch seems incomplete, only patching the first regexp
+>> but not the other two in the same function, which also are quoting-aware. --[[Joey]]