When I use the following constraints:

    ^.{6,8}$
    [0-9]
    [A-Z]
    [a-z]

I get:

    F񣛯7򴘇󢎺򋛠o
    d1󴆂󯹓󶄁񪥴A񴊆
    𑐟Ku򍅼󨫢9􆯩
    𑍞4񾋚𢗏Rw򂚃񷰗
    I򹪴𦢺򎐝2𵞎򓛹r

I don't think those block chars should be there. Am I missing something?

Okay, this is kindof incredible. The ability to create a complicated regex from smaller pieces combined in a logical way is insane. This has so many uses.

https://github.com/gruhn/regex-utils#comment-regex-using-com...

Heh, cool concept. Could maybe add some interactive configuration common password gen tools have like choose length, characters used (upper, lower, numbers, symbols) so people not accustomed to regex can play with (and see how for each configuration the regex changes).

Your regex-utils library also interesting, especially the set operations part.

Nice, wonder if this can integrated into password managers!