Regex::Explain output

regex_in_touchdb

The regular expression:

(?-imsx:^abcdefghijklmnopqrstuvwxyz0123456789_$()+-/)

matches as follows:
  
NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  abcdefghijklmnopqrst     'abcdefghijklmnopqrstuvwxyz0123456789_'
  uvwxyz0123456789_
----------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string
----------------------------------------------------------------------
  (                        group and capture to \1 (1 or more times
                           (matching the most amount possible)):
----------------------------------------------------------------------
  )+                       end of \1 (NOTE: because you are using a
                           quantifier on this capture, only the LAST
                           repetition of the captured pattern will be
                           stored in \1)
----------------------------------------------------------------------
  -/                       '-/'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------