1.0
-1.0
.9
9.
-.9
-.4e08
+4.E-08
+.2e+219
2.00001e+9

##</code><code>##

our $numregex = qr/^
        # may have leading plus or minus
        [-+]?
        # one of these formats must exist
        (?:
          # maybe one or more digits, then decimal, and maybe more digits
          \d+\.?\d*
          # or decimal followed by one or more digits
          |\.\d+
        )
        # optional sci notation
        (?:
          # "e" or "E" and plus or minus, and one, two, or three digits
          [eE][-+]\d{1,3}
        )?
        $/x;