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# frozen_string_literal: true
module Gitlab
module Graphql
# This module allows your class to easily defer and force values.
# Its methods are just sugar for calls to the Gitlab::Graphql::Lazy class.
#
# example:
#
# class MyAwesomeClass
# include ::Gitlab::Graphql::Laziness
#
# # takes a list of id and list of factors, and computes
# # sum of [SomeObject[i]#value * factor[i]]
# def resolve(ids:, factors:)
# ids.zip(factors)
# .map { |id, factor| promise_an_int(id, factor) }
# .map(&method(:force))
# .sum
# end
#
# # returns a promise for an Integer
# def (id, factor)
# thunk = SomeObject.lazy_find(id)
# defer { force(thunk).value * factor }
# end
# end
#
# In the example above, we use defer to delay forcing the batch-loaded
# item until we need it, and then we use `force` to consume the lazy values
#
# If `SomeObject.lazy_find(id)` batches correctly, calling
# `resolve` will only perform one batched load for all objects, rather than
# loading them individually before combining the results.
#
module Laziness
def defer(&block)
::Gitlab::Graphql::Lazy.new(&block)
end
def force(lazy)
::Gitlab::Graphql::Lazy.force(lazy)
end
end
end
end
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