Pattern Expander

Installation

Add this line to your application's Gemfile:

gem 'pattern_expander'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pattern_expander

Usage

Takes patterns and outputs their combinations - think reverse regex. Lazily loads "pages" of combinations and returns results before the heat death of the universe.

Pass in a string with randomly chosen values in square brackets"[]":

expander = PatternExpander.new(
  "My [startup|band|puppy's] name is [i|e||Power |Awesome ][Ninja|Rockstar] [Ministry|Labs|Quux]"
)

Get random samples with #sample:

expander.sample # my startup name is Power Rockstar Ministry
expander.sample # my puppy's name is iNinja Labs
expander.sample(3) # get multiple samples

Get specific index values:

expander = PatternExpander.new("[a|b][1|2]")
expander[0] # "a1"
expander[1] # "a2"
expander[0..3] # ["a1", "a2", "b1", "b2"]

By default you can use "+d" and "+w" to map to digits and alphanumeric characters. Here's an example of constructing a big UUID like pattern:

expander = PatternExpander.new(
  "[+w][+w][+w][+w]-[+w][+w][+w][+w]-[+w][+w][+w][+w]-[+w][+w][+w][+w]"
)
expander.sample # "eo6a-68m6-coxw-14j7"
expander[10_000_000_000..10_000_000_002]
# returns ["aaaa-aaaa-aaaa-ahz2", "aaaa-aaaa-aaaa-ahz3", "aaaa-aaaa-aaaa-ahz4"]

And you can pass your own substitutes in and come up with your next startup elevator pitch:

expander = PatternExpander.new("It's like [+company] for [+customer]",
  substitutes: {
   '+company' =>  ['Chat Roulette',  'Kickstarter', 'Stack Overflow', 'SpaceX'],
   '+customer' => ['Texas', 'pets', 'tweens', 'magicians', 'figure skaters']
  }
)
expander.sample # It's like Chat Roulette for magicians
expander.sample # It's like Stack Overflow for Texas
expander.sample # It's like SpaceX for figure skaters

TODO

• Sample should return any value only once
• Error when max range has been exceeded for the index
• Delegate methods from PatternExpander to CombinationIndex
• API for adding substitutes
• PatternExpander#all(max:n)
• Filters (e.g. matches pattern, not in exclusion set, max length)
• Ranges for filtered results

Contributing

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