[Wroc_Love.rb 2018] [Lightning Talk] To refine or not to refine

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TO REFINE OR NOT TO REFINE Vladimir Dementyev

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No content

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HISTORY Introduced in Ruby 2.0.0 Has been experimental until 2.1

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“Developed my Matz’s boss, Shugo” “Initially was more powerful but JRuby…" "Koichi Sasada wants to remove Reﬁnements” http://rubynoname.ru/posts/2017/S08E08.html *2016

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EXAMPLES asakusarb/action_args amatsuda/database_rewinder

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EXAMPLES

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EXAMPLES https://github.com/rails/rails/pull/27363

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USE CASES

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DEPENDENCY REDUCTION module Anyway ::HashExt refine Hash do def stringify_keys! keys.each do |key| val = delete(key) val.stringify_keys! if val.is_a?(Hash) self[key.to_s] = val end end end end https://github.com/palkan/anyway_conﬁg

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class Anyway ::Config using Anyway ::Ext ::DeepDup using Anyway ::Ext ::Hash def self.attr_config(*args, **hargs) @defaults = hargs.deep_dup defaults.stringify_keys! @config_attributes = args + defaults.keys attr_accessor(*@config_attributes) end end https://github.com/palkan/anyway_conﬁg DEPENDENCY REDUCTION

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MODERNIZATION module ThreadFetch # Thread.fetch is only available since 2.5 refine Thread do def fetch(key, fallback = : __undef __) raise KeyError, "key not found: #{key}" if !key?(key) && fallback == : __undef __ self[key] || fallback end end end https://github.com/palkan/isolator

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PERFECT PRIVACY if Array.instance_methods(false).include?(:sum) && !(%w[a].sum rescue false) # Using Refinements here in # order not to expose our internal method using Module.new { refine Array do alias :orig_sum :sum end } #… end https://github.com/rails/rails/pull/27363/ﬁles

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DSL https://github.com/k-tsj/pattern-match using PatternMatch match(object) do with(pattern[, guard]) do ... end with(pattern[, guard]) do ... end ... end

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to_proc https://github.com/palkan/clowne # Add to_proc method for lambda module LambdaAsProc refine Proc do def to_proc return self unless lambda? this = self proc { |*args| this.call(*args.take(this.arity)) } end end end

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SYNTAX SUGAR https://github.com/palkan/test-prof using FloatDuration using StringStripHeredoc msg = <<-MSG.strip_heredoc EventProf results for #{@profiler.event} Total time: #{@profiler.total_time.duration} MSG

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#PROTIP module Json refine Integer do def to_json to_s end end end using Json p Module.used_modules # => [Json]

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TRUFFLE BONUS

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PROBLEMS?

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PROBLEMS

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PROBLEMS module Json refine Integer do def to_json to_s end end end using Json p 1.send(:to_json) # => "1" p 1.public_send(:to_json) # => NoMethodError