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)
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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)
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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)
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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