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

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