Greeb [grʲip] is a simple yet awesome and Unicode-aware text segmentator that is based on regular expressions. The API documentation is available at The software demonstration is available on


Add this line to your application's Gemfile:

gem 'greeb'

And then execute:

$ bundle

Or install it yourself as:

$ gem install greeb


Greeb can help you solve simple text processing problems such as tokenization and segmentation.

It is available as a command line application that reads the input text from STDIN and prints one token per line into STDOUT.

% echo 'Hello guys, how are you?' | greeb

Tokenization API

Greeb has a very convinient API that makes you happy.

pp Greeb::Tokenizer.tokenize('Hello!')
[#<struct Greeb::Span from=0, to=5, type=:letter>,
 #<struct Greeb::Span from=5, to=6, type=:punct>]

It should be noted that it is possible to process much complex texts.

text =<<-EOF
Hello! I am 18! My favourite number is 133.7...

What about you?

pp Greeb::Tokenizer.tokenize(text)
[#<struct Greeb::Span from=0, to=5, type=:letter>,
 #<struct Greeb::Span from=5, to=6, type=:punct>,
 #<struct Greeb::Span from=6, to=7, type=:space>,
 #<struct Greeb::Span from=7, to=8, type=:letter>,
 #<struct Greeb::Span from=8, to=9, type=:space>,
 #<struct Greeb::Span from=9, to=11, type=:letter>,
 #<struct Greeb::Span from=11, to=12, type=:space>,
 #<struct Greeb::Span from=12, to=14, type=:integer>,
 #<struct Greeb::Span from=14, to=15, type=:punct>,
 #<struct Greeb::Span from=15, to=16, type=:space>,
 #<struct Greeb::Span from=16, to=18, type=:letter>,
 #<struct Greeb::Span from=18, to=19, type=:space>,
 #<struct Greeb::Span from=19, to=28, type=:letter>,
 #<struct Greeb::Span from=28, to=29, type=:space>,
 #<struct Greeb::Span from=29, to=35, type=:letter>,
 #<struct Greeb::Span from=35, to=36, type=:space>,
 #<struct Greeb::Span from=36, to=38, type=:letter>,
 #<struct Greeb::Span from=38, to=39, type=:space>,
 #<struct Greeb::Span from=39, to=44, type=:float>,
 #<struct Greeb::Span from=44, to=47, type=:punct>,
 #<struct Greeb::Span from=47, to=49, type=:break>,
 #<struct Greeb::Span from=49, to=53, type=:letter>,
 #<struct Greeb::Span from=53, to=54, type=:space>,
 #<struct Greeb::Span from=54, to=59, type=:letter>,
 #<struct Greeb::Span from=59, to=60, type=:space>,
 #<struct Greeb::Span from=60, to=63, type=:letter>,
 #<struct Greeb::Span from=63, to=64, type=:punct>,
 #<struct Greeb::Span from=64, to=65, type=:break>]

Segmentation API

Also it can be used to solve the text segmentation problems such as sentence detection tasks.

text = 'Hello! How are you?'
tokens = Greeb::Tokenizer.tokenize(text)
[#<struct Greeb::Span from=0, to=6, type=:sentence>,
 #<struct Greeb::Span from=7, to=19, type=:sentence>]

It is possible to extract tokens that were processed by the text segmentator.

text = 'Hello! How are you?'
tokens = Greeb::Tokenizer.tokenize(text)
segmentator =
pp segmentator.extract(segmentator.sentences)
{#<struct Greeb::Span from=0, to=6, type=:sentence>=>
  [#<struct Greeb::Span from=0, to=5, type=:letter>,
   #<struct Greeb::Span from=5, to=6, type=:punct>],
 #<struct Greeb::Span from=7, to=19, type=:sentence>=>
  [#<struct Greeb::Span from=7, to=10, type=:letter>,
   #<struct Greeb::Span from=10, to=11, type=:space>,
   #<struct Greeb::Span from=11, to=14, type=:letter>,
   #<struct Greeb::Span from=14, to=15, type=:space>,
   #<struct Greeb::Span from=15, to=18, type=:letter>,
   #<struct Greeb::Span from=18, to=19, type=:punct>]}

Parsing API

Texts are often include some special spans such as URLs and e-mail addresses. Greeb can help you in these strings retrieval.

URL and E-mail retrieval

text = 'My website is and e-mail is'

pp Greeb::Parser.urls(text).map { |e| [e, e.slice(text)] }
[[#<struct Greeb::Span from=14, to=29, type=:url>, ""]]

pp Greeb::Parser.emails(text).map { |e| [e, e.slice(text)] }
[[#<struct Greeb::Span from=44, to=63, type=:email>, ""]]

Please don't use Greeb in spam lists development purposes.

Abbreviation retrieval

text = 'Hello, G.L.H.F. everyone!'

pp Greeb::Parser.abbrevs(text).map { |e| [e, e.slice(text)] }
[[#<struct Greeb::Span from=7, to=15, type=:abbrev>, "G.L.H.F."]]

The algorithm is not so accurate, but still useful in many practical situations.

Timestamps retrieval

text = 'Our time is running out: 13:37 or 14:89.'

pp Greeb::Parser.time(text).map { |e| [e, e.slice(text)] }
[[#<struct Greeb::Span from=25, to=30, type=:time>, "13:37"]]


Greeb operates with spans, tuples of (from, to, kind), where from is a beginning of the span, to is an ending of the span, and kind is a type of the span.

There are several span types at the tokenization stage: :letter, :float, :integer, :separ, :punct (for punctuation), :spunct (for in-sentence punctuation), :space, and :break.


  1. Fork it;
  2. Create your feature branch (git checkout -b my-new-feature);
  3. Commit your changes (git commit -am 'Added some feature');
  4. Push to the branch (git push origin my-new-feature);
  5. Create new Pull Request.

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Copyright (c) 2010-2014 Dmitry Ustalov. See LICENSE for details.