module Buff::Extensions::Hash::Slice

Borrowd and modified from {github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/hash/slice.rb}

Public Instance Methods

extract!(*keys) click to toggle source

Removes and returns the key/value pairs matching the given keys.

{ a: 1, b: 2, c: 3, d: 4 }.extract!(:a, :b) # => {:a=>1, :b=>2}
{ a: 1, b: 2 }.extract!(:a, :x)             # => {:a=>1}
# File lib/buff/extensions/hash/slice.rb, line 41
def extract!(*keys)
  keys.each_with_object(self.class.new) { |key, result| result[key] = delete(key) if has_key?(key) }
end
slice(*keys) click to toggle source

Slice a hash to include only the given keys. This is useful for limiting an options hash to valid keys before passing to a method:

def search(criteria = {})
  criteria.assert_valid_keys(:mass, :velocity, :time)
end

search(options.slice(:mass, :velocity, :time))

If you have an array of keys you want to limit to, you should splat them:

valid_keys = [:mass, :velocity, :time]
search(options.slice(*valid_keys))
# File lib/buff/extensions/hash/slice.rb, line 19
def slice(*keys)
  keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true)
  keys.each_with_object(self.class.new) { |k, hash| hash[k] = self[k] if has_key?(k) }
end
slice!(*keys) click to toggle source

Replaces the hash with only the given keys. Returns a hash containing the removed key/value pairs.

{ a: 1, b: 2, c: 3, d: 4 }.slice!(:a, :b)
# => {:c=>3, :d=>4}
# File lib/buff/extensions/hash/slice.rb, line 29
def slice!(*keys)
  keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true)
  omit = slice(*self.keys - keys)
  hash = slice(*keys)
  replace(hash)
  omit
end