re = /^[+-]?(?!\.(?!\d)|$)\d*(?:\.\d*)?(?:(?<=[\d.])e[+-]?\d+)?$/im
str = '0
.
.0
0.
0.0
1
123456.789
e123
1e4
1e4.5
1.4e4
1.4
1.4e
1.4e0
1.e4
.e4
0.e4
-
1e-4
1e+4
1e-
1e+'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html