Being replaced by kddnewton/exreg.
A regular expression engine written in Ruby.
Add this line to your application's Gemfile:
gem "regular_expression"
And then execute:
$ bundle install
Or install it yourself as:
$ gem install regular_expression
One of the backends that the regular expression compiler can use is cranelift, which is a rust project with Ruby bindings handled by the cranelift_ruby
gem. In order to use the compiler, you'll need to have cargo
installed so that it can compile the rust native extension. On a Mac or Linux you can curl https://sh.rustup.rs -sSf | sh
. For other platforms, searching install cargo can tell you how. Additionally, you'll need your Ruby to have been compiled with the --enable-shared
option.
To call #disasm
on the generated machine code, you'll need Capstone installed. On a Mac you can brew install capstone
, or on Ubuntu you can sudo apt-get install libcapstone-dev
. For other platforms, searching install capstone can tell you how.
To call #to_dot
on the syntax tree or the state machines, or run the tests, you'll need Graphviz installed. On a Mac you can brew install graphviz
, or on Ubuntu you can sudo apt-get install graphviz
. For other platforms, searching install graphviz can tell you how.
To create a regular expression pattern, use:
pattern = RegularExpression::Pattern.new("ab?c")
Patterns can be queried for whether or not they match a test string, as in:
pattern.match?("abc") # => true
pattern.match?("ac") # => true
pattern.match?("ab") # => false
After installing the dependencies checking out the repo, run bundle install
to install dependencies. Then, run bundle exec rake test
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
At the moment we support most basic features, but there is a lot of ground left to cover. Some of them are written out in issues, while others are just documented here. Here is the current list as it stands:
Syntax | Status | Issue |
---|---|---|
Character classes | 🛠 | #6 |
Repetition | ✅ | |
Non-greedy repetition | ❌ | |
Capturing | 🛠 | #3 |
Named captures | ✅ | #84 |
Grouping | ✅ | |
Atomic grouping | ❌ | |
Subexpression calls | ❌ | |
Alternation | ✅ | |
Character properties | 🛠 | #8 |
Anchors | 🛠 | #9 |
Assertions | 🛠 | #10 |
Case-insensitive mode | 🛠 | #4 |
Multi-line mode | ❌ | #5 |
Free-spacing mode | ✅ | #11 |
Encoding support | ❌ | #12 |
Backreferences | ❌ |
To benchmark the current performance on your current version of Ruby, run:
$ bundle exec rake benchmark
Bug reports and pull requests are welcome on GitHub at https://github.com/kddnewton/regular_expression. For information about how to contribute to the development of this gem, see the CONTRIBUTING.md document.
The gem is available as open source under the terms of the MIT License.