Class: Hash
- Inherits:
-
Object
- Object
- Hash
- Defined in:
- lib/ext/hash/keys.rb,
lib/ext/hash/slice.rb,
lib/ext/hash/except.rb
Instance Method Summary collapse
-
#assert_valid_keys(*valid_keys) ⇒ Object
Validates all keys in a hash match
*valid_keys
, raisingArgumentError
on a mismatch. -
#deep_stringify_keys ⇒ Object
Returns a new hash with all keys converted to strings.
-
#deep_stringify_keys! ⇒ Object
Destructively converts all keys to strings.
-
#deep_symbolize_keys ⇒ Object
Returns a new hash with all keys converted to symbols, as long as they respond to
to_sym
. -
#deep_symbolize_keys! ⇒ Object
Destructively converts all keys to symbols, as long as they respond to
to_sym
. -
#deep_transform_keys(&block) ⇒ Object
Returns a new hash with all keys converted by the block operation.
-
#deep_transform_keys!(&block) ⇒ Object
Destructively converts all keys by using the block operation.
-
#except(*keys) ⇒ Object
Returns a hash that includes everything except given keys.
-
#except!(*keys) ⇒ Object
Removes the given keys from hash and returns it.
-
#extract!(*keys) ⇒ Object
Removes and returns the key/value pairs matching the given keys.
-
#slice(*keys) ⇒ Object
Slices a hash to include only the given keys.
-
#slice!(*keys) ⇒ Object
Replaces the hash with only the given keys.
-
#stringify_keys ⇒ Object
Returns a new hash with all keys converted to strings.
-
#stringify_keys! ⇒ Object
Destructively converts all keys to strings.
-
#symbolize_keys ⇒ Object
(also: #to_options)
Returns a new hash with all keys converted to symbols, as long as they respond to
to_sym
. -
#symbolize_keys! ⇒ Object
(also: #to_options!)
Destructively converts all keys to symbols, as long as they respond to
to_sym
. -
#transform_keys ⇒ Object
Returns a new hash with all keys converted using the
block
operation. -
#transform_keys! ⇒ Object
Destructively converts all keys using the
block
operations.
Instance Method Details
#assert_valid_keys(*valid_keys) ⇒ Object
Validates all keys in a hash match *valid_keys
, raising ArgumentError
on a mismatch.
Note that keys are treated differently than HashWithIndifferentAccess, meaning that string and symbol keys will not match.
{ name: 'Rob', years: '28' }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key: :years. Valid keys are: :name, :age"
{ name: 'Rob', age: '28' }.assert_valid_keys('name', 'age') # => raises "ArgumentError: Unknown key: :name. Valid keys are: 'name', 'age'"
{ name: 'Rob', age: '28' }.assert_valid_keys(:name, :age) # => passes, raises nothing
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# File 'lib/ext/hash/keys.rb', line 75 def assert_valid_keys(*valid_keys) valid_keys.flatten! each_key do |k| unless valid_keys.include?(k) raise ArgumentError.new("Unknown key: #{k.inspect}. Valid keys are: #{valid_keys.map(&:inspect).join(', ')}") end end end |
#deep_stringify_keys ⇒ Object
Returns a new hash with all keys converted to strings. This includes the keys from the root hash and from all nested hashes and arrays.
hash = { person: { name: 'Rob', age: '28' } }
hash.deep_stringify_keys
# => {"person"=>{"name"=>"Rob", "age"=>"28"}}
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# File 'lib/ext/hash/keys.rb', line 111 def deep_stringify_keys deep_transform_keys(&:to_s) end |
#deep_stringify_keys! ⇒ Object
Destructively converts all keys to strings. This includes the keys from the root hash and from all nested hashes and arrays.
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# File 'lib/ext/hash/keys.rb', line 118 def deep_stringify_keys! deep_transform_keys!(&:to_s) end |
#deep_symbolize_keys ⇒ Object
Returns a new hash with all keys converted to symbols, as long as they respond to to_sym
. This includes the keys from the root hash and from all nested hashes and arrays.
hash = { 'person' => { 'name' => 'Rob', 'age' => '28' } }
hash.deep_symbolize_keys
# => {:person=>{:name=>"Rob", :age=>"28"}}
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# File 'lib/ext/hash/keys.rb', line 130 def deep_symbolize_keys deep_transform_keys{ |key| key.to_sym rescue key } end |
#deep_symbolize_keys! ⇒ Object
Destructively converts all keys to symbols, as long as they respond to to_sym
. This includes the keys from the root hash and from all nested hashes and arrays.
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# File 'lib/ext/hash/keys.rb', line 137 def deep_symbolize_keys! deep_transform_keys!{ |key| key.to_sym rescue key } end |
#deep_transform_keys(&block) ⇒ Object
Returns a new hash with all keys converted by the block operation. This includes the keys from the root hash and from all nested hashes and arrays.
hash = { person: { name: 'Rob', age: '28' } }
hash.deep_transform_keys{ |key| key.to_s.upcase }
# => {"PERSON"=>{"NAME"=>"Rob", "AGE"=>"28"}}
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# File 'lib/ext/hash/keys.rb', line 92 def deep_transform_keys(&block) _deep_transform_keys_in_object(self, &block) end |
#deep_transform_keys!(&block) ⇒ Object
Destructively converts all keys by using the block operation. This includes the keys from the root hash and from all nested hashes and arrays.
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# File 'lib/ext/hash/keys.rb', line 99 def deep_transform_keys!(&block) _deep_transform_keys_in_object!(self, &block) end |
#except(*keys) ⇒ Object
Returns a hash that includes everything except given keys.
hash = { a: true, b: false, c: nil }
hash.except(:c) # => { a: true, b: false }
hash.except(:a, :b) # => { c: nil }
hash # => { a: true, b: false, c: nil }
This is useful for limiting a set of parameters to everything but a few known toggles:
@person.update(params[:person].except(:admin))
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# File 'lib/ext/hash/except.rb', line 10 def except(*keys) dup.except!(*keys) end |
#except!(*keys) ⇒ Object
Removes the given keys from hash and returns it.
hash = { a: true, b: false, c: nil }
hash.except!(:c) # => { a: true, b: false }
hash # => { a: true, b: false }
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# File 'lib/ext/hash/except.rb', line 18 def except!(*keys) keys.each { |key| delete(key) } self end |
#extract!(*keys) ⇒ Object
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}
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# File 'lib/ext/hash/slice.rb', line 45 def extract!(*keys) keys.each_with_object(self.class.new) { |key, result| result[key] = delete(key) if has_key?(key) } end |
#slice(*keys) ⇒ Object
Slices a hash to include only the given keys. Returns a hash containing the given keys.
{ a: 1, b: 2, c: 3, d: 4 }.slice(:a, :b)
# => {:a=>1, :b=>2}
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(.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(.slice(*valid_keys))
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# File 'lib/ext/hash/slice.rb', line 21 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) ⇒ Object
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}
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# File 'lib/ext/hash/slice.rb', line 31 def slice!(*keys) keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true) omit = slice(*self.keys - keys) hash = slice(*keys) hash.default = default hash.default_proc = default_proc if default_proc replace(hash) omit end |
#stringify_keys ⇒ Object
Returns a new hash with all keys converted to strings.
hash = { name: 'Rob', age: '28' }
hash.stringify_keys
# => {"name"=>"Rob", "age"=>"28"}
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# File 'lib/ext/hash/keys.rb', line 37 def stringify_keys transform_keys(&:to_s) end |
#stringify_keys! ⇒ Object
Destructively converts all keys to strings. Same as stringify_keys
, but modifies self
.
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# File 'lib/ext/hash/keys.rb', line 43 def stringify_keys! transform_keys!(&:to_s) end |
#symbolize_keys ⇒ Object Also known as: to_options
Returns a new hash with all keys converted to symbols, as long as they respond to to_sym
.
hash = { 'name' => 'Rob', 'age' => '28' }
hash.symbolize_keys
# => {:name=>"Rob", :age=>"28"}
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# File 'lib/ext/hash/keys.rb', line 54 def symbolize_keys transform_keys{ |key| key.to_sym rescue key } end |
#symbolize_keys! ⇒ Object Also known as: to_options!
Destructively converts all keys to symbols, as long as they respond to to_sym
. Same as symbolize_keys
, but modifies self
.
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# File 'lib/ext/hash/keys.rb', line 61 def symbolize_keys! transform_keys!{ |key| key.to_sym rescue key } end |
#transform_keys ⇒ Object
Returns a new hash with all keys converted using the block
operation.
hash = { name: 'Rob', age: '28' }
hash.transform_keys { |key| key.to_s.upcase } # => {"NAME"=>"Rob", "AGE"=>"28"}
If you do not provide a block
, it will return an Enumerator for chaining with other methods:
hash.transform_keys.with_index { |k, i| [k, i].join } # => {"name0"=>"Rob", "age1"=>"28"}
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# File 'lib/ext/hash/keys.rb', line 12 def transform_keys return enum_for(:transform_keys) { size } unless block_given? result = self.class.new each_key do |key| result[yield(key)] = self[key] end result end |
#transform_keys! ⇒ Object
Destructively converts all keys using the block
operations. Same as transform_keys
but modifies self
.
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# File 'lib/ext/hash/keys.rb', line 23 def transform_keys! return enum_for(:transform_keys!) { size } unless block_given? keys.each do |key| self[yield(key)] = delete(key) end self end |