Module: Enumerable

Defined in:
lib/rext/enumerable/helpers.rb

Defined Under Namespace

Classes: Proxy

Instance Method Summary collapse

Instance Method Details

#drop(n = 1, &block) ⇒ Object

Drop n elements, returning the others. You may also pass a block which acts as Enumerable#reject.

Examples

[1,2,3,4].drop                  # => [2,3,4]
[1,2,3,4].drop(2)               # => [3,4]
[1,2,3,4].drop(-2)              # => [1,2]
[1,2,3,4,5].drop { |n| n < 4 }  # => [4,5]



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# File 'lib/rext/enumerable/helpers.rb', line 101

def drop n = 1, &block
  case 
  when block ; reject &block
  when n < 0 ; self[0...n]
  else         self[n..-1]
  end
end

#every(&block) ⇒ Object

Sexy Symbol#to_proc replacement for mapping enums.

Examples

names = %w( tj scott joe bob )
names.every.length.join          # => 2533
names.every.empty?.any?          # => false
names.every { length > 4 }.all?  # => true



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# File 'lib/rext/enumerable/helpers.rb', line 71

def every &block
  block ? proxy(:map).instance_eval(&block) : proxy(:map)
end

#group_by(&block) ⇒ Object

Return a hash grouped by block.

Examples

words = %w( just some foo bar )
words.group_by { |word| word.length }  # => {3=>["foo", "bar"], 4=>["just", "some"]}
words.group_by { length }              # => {3=>["foo", "bar"], 4=>["just", "some"]}
words.group_by.length                  # => {3=>["foo", "bar"], 4=>["just", "some"]}



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# File 'lib/rext/enumerable/helpers.rb', line 52

def group_by &block
  return proxy(:group_by) unless block
  inject({}) do |hash, value|
    (hash[block.yield_or_eval(value)] ||= []) << value
    hash
  end
end

#includes_all?(*args) ⇒ Boolean

Check if all args are included.

Examples

permissions = 'save', 'edit', 'delete'
permissions.includes_all? 'save', 'edit'    # => true

Returns:

  • (Boolean) 


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# File 'lib/rext/enumerable/helpers.rb', line 84

def includes_all? *args
  args.all? { |arg| include? arg }
end

#proxy(meth) ⇒ Object

Shortcut for Proxy.new self, meth.



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# File 'lib/rext/enumerable/helpers.rb', line 37

def proxy meth
  Proxy.new self, meth
end

#take(n = 1, &block) ⇒ Object

Take n elements, or pass a block which acts as Enumerable#select.

Examples

[1,2,3,4].take              # => [1]
[1,2,3,4].take(2)           # => [1,2]
[1,2,3,4].take(-2)          # => [3,4]
[1,2,3,4].take { |n| == 1 } # => [1]



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# File 'lib/rext/enumerable/helpers.rb', line 121

def take n = 1, &block
  case 
  when block ; select &block
  when n < 0 ; self[n..-1]
  else         self[0...n]
  end
end