Character classes summary


a[bc]a      # aba, aca
a[2#=x?.]a  # a2a, a#a, a=a, axa, a?a, a.a
            # inside the character class most of the spec characters lose their
            # special meaning  BUT there are some new special characters
a[2-8]a     # is the same as /a[2345678]a/
a[2-]a      # a2a, a-a        - has no special meaning at the ends
a[-8]a      # a8a, a-a
a[6-C]a     # a6a, a7a ... aCa
              #      characters from the ASCII table: 6789:;&lt;=&gt;?@ABC
a[C-6]a     # Error: "bad character range"

a[^xa]a     # "aba", "aca"  but not "aaa", "axa"    what about "aa" ?
              # ^ as the first character in a character class means 
              # a character that is not in the list
a[a^x]a     # aaa, a^a, axa