module Roadie::Rails::Utils
Public Instance Methods
Return a callable that will call both inputs. If either is nil, then just return the other.
The result from the second one will be the result of the combined callable.
“‘ruby combine_callable
(-> { 1 }, -> { 2 }).call # => 2 combine_callable
(-> { 1 }, nil).call # => 1 combine_callable
(nil, nil).nil? # => true “`
# File lib/roadie/rails/utils.rb, line 27 def combine_callable(first, second) combine_nilable(first, second) do |a, b| lambda do |*args| a.call(*args) b.call(*args) end end end
Combine two hashes, or return the non-nil hash if either is nil. Returns nil if both are nil.
# File lib/roadie/rails/utils.rb, line 10 def combine_hash(first, second) combine_nilable(first, second) do |a, b| a.merge(b) end end
Discard the nil value. If neither is nil, then yield both and return the result from the block.
“‘ruby combine_nilable
(nil, 5) { |a, b| a+b } # => 5 combine_nilable
(7, nil) { |a, b| a+b } # => 7 combine_nilable
(nil, nil) { |a, b| a+b } # => nil combine_nilable
(7, 5) { |a, b| a+b } # => 12 “`
# File lib/roadie/rails/utils.rb, line 53 def combine_nilable(first, second) if first && second yield first, second else first || second end end
Combine two Provider ducks into a ProviderList. If either is nil, pick the non-nil value instead.
# File lib/roadie/rails/utils.rb, line 38 def combine_providers(first, second) combine_nilable(first, second) do |a, b| ProviderList.new(a.to_a + Array.wrap(b)) end end