wikilink_regex

r'''\[\[                    # Match two opening brackets
    (?P<link>               # <link>:
        [^\|]{0,256}?       # Text inside link group
                            # everything not a pipe, non-greedy
                            # up to 256 characters
    )
    \|?                     # Match an optional pipe
    (?P<anchor>             # <anchor>:
        [^\|]{0,4096}?      # Text inside anchor group
                            # everything not a pipe, non-greedy
                            # up to 4096 characters
    )
    \]\]                    # Match two closing brackets
'''