YAPE-Regex-Explain-4.01› perl examples/explain
\-?(?:\d+\.?\d*|\.\d+)
The regular expression:

(?-imsx:\-?(?:\d+\.?\d*|\.\d+))

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):
----------------------------------------------------------------------
  \-?                      '-' (optional (matching the most amount
                           possible))
----------------------------------------------------------------------
  (?:                      group, but do not capture:
----------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
    \.?                      '.' (optional (matching the most amount
                             possible))
----------------------------------------------------------------------
    \d*                      digits (0-9) (0 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    \.                       '.'
----------------------------------------------------------------------
    \d+                      digits (0-9) (1 or more times (matching
                             the most amount possible))
----------------------------------------------------------------------
  )                        end of grouping
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------