Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tree: 2ef4d5ed5c
Fetching contributors…

Cannot retrieve contributors at this time

41 lines (38 sloc) 1.392 kb
class Hash
# 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))
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
# 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}
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
# 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}
def extract!(*keys)
keys.each_with_object(self.class.new) { |key, result| result[key] = delete(key) if has_key?(key) }
end
end
Jump to Line
Something went wrong with that request. Please try again.