VerbalExpressions is a Ruby library that helps to construct difficult regular expressions - ported from the awesome JavaScript VerbalExpressions.

Just install with gem install verbal_expressions, then require the library and you're good to go!

require 'verbal_expressions'

Here's a couple of simple examples to give an idea of how VerbalExpressions works:

# Create an example of how to test for correctly formed URLs
tester = VerEx.new do
  start_of_line
  find 'http'
  maybe 's'
  find '://'
  maybe 'www.'
  anything_but ' '
  end_of_line
end
# Create an example URL
test_url = "https://www.google.com"
# Use it just like a regular Ruby regex:
puts 'Hooray!  It works!' if tester.match(test_url)
puts 'This works too!' if tester =~ test_url
# Print the generated regex:
puts tester.source # => /^(http)(s)?(\:\/\/)(www\.)?([^\ ]*)$/ 

# Create a test string
replace_me = "Replace bird with a duck"
# Create an expression that seeks for word "bird"
expression = VerEx.new { find 'bird' }
# Execute the expression like a normal Regexp object
result = replace_me.gsub( expression, "duck" );
puts result # Outputs "Replace duck with a duck"

I haven't added much documentation to this repo yet, but you can find the documentation for the original JavaScript repo on their wiki. Most of the methods have been ported as of v0.1.0 of the JavaScript repo. Just be sure to use the syntax explained above rather than the dot notation :)

Clone the repo and fork!
Pull requests are warmly welcomed!

• I haven't yet ported the modifier code because Ruby Regexp handles modifiers a little differently.
• Because or is reserved in Ruby, or is currently aliased to alternatively. Unforunately, then is also reserved, so you must use find instead. I'm very open to better name ideas :)

Thank you to @jehna for coming up with the awesome original idea!

You can view all implementations on VerbalExpressions.github.io