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Izzy Module

To demo Izzy, let's make a Person:

brandon ='brandon', 23, 'm')


Let's do some matching against it:

brandon.matches_all?  name: /^br/, age: (20..30) # => true
brandon.matches_any?  name: /br$/, age: (20..30) # => true
brandon.matches_none? name: /br&/, age: (30..40) # => true

Type Checking

Perhaps you want to type check:

brandon.matches_all? name: String, age: Integer


Need a bit more power? We have Lambdas for that!

longer_than_3 = -> n { n.length > 3 }
is_odd = -> a { a.odd? }

brandon.matches_all? name: longer_than_3, age: is_odd # => true

Multi Matchers

....or let's push it further for some interesting results:

longer_than_5 = -> n { n.length > 5 }
greater_than_20 = -> a { a > 20 }

  name: [/br/, /an/, longer_than_5],
  age: [(20..30), greater_than_20]

# => true

Boolean Matchers

...and do some comparisons on boolean methods!

brandon.all_of?  :older_than_18?, :male?, :me?, :geek? # => true
brandon.none_of? :younger_than_18?, :female?           # => true
brandon.any_of?  :male?, :female?, :geek?              # => true

Izzy Array Module

IzzyArray allows you a few more tricks on top of that!

class Array; include IzzyArray end

[0,0,0].all_are :zero?       # => true
[0,nil,'foo'].any_are :zero? # => true
[0,0,0].none_are :nil?       # => true

Combine with rails :present?, :empty?, and various other methods and you have some interesting results! This one will get some more power with experimentation.

Izzy Enumerable

Let's get ourselves a collection to use:

class Object; include Izzy end

brandon ='brandon', 23, 'm')
john    ='john',    42, 'm')
jill    ='jill',    31, 'f')
alice   ='alice',   50, 'f')
zeke    ='zeke',    18, 'm')

people = [brandon, john, jill, alice, zeke]

Select Where

Select all objects where params match:

people.select_where name: /^j/
# => [john, jill]

  age: [
    -> a { a.odd? }
# => [brandon]

Reject Where

Reject all objects where params match:

people.reject_where name: /^j/
# => [brandon, alice, zeke]

  age: [
    -> a { a.odd? }
# => [john, jill, alice, zeke]

Find Where

Finds the first object where params match:

people.find_where name: /^j/, gender: 'm'
# => john


Add this line to your application's Gemfile:

gem 'izzy'

And then execute:

$ bundle

Or install it yourself as:

$ gem install izzy


It patches object, just use it with any method that matches the pattern is_foo? and you're good to go!


  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
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