[#54738] [ruby-trunk - Bug #8358][Open] TestSprintf#test_float test failuer on mingw32 — "phasis68 (Heesob Park)" <phasis@...>

36 messages 2013/05/02

[#54749] [ruby-trunk - Feature #8361][Open] Alternative syntax for block parameter — "alexeymuranov (Alexey Muranov)" <redmine@...>

12 messages 2013/05/02

[#54798] [ruby-trunk - Bug #8370][Open] Constants MAX_MULTIPART_LENGTH in cgi\core.rb — "xibbar (Takeyuki FUJIOKA)" <xibbar@...>

17 messages 2013/05/05

[#54850] [ruby-trunk - Feature #8377][Open] Deprecate :: for method calls in 2.1 — "charliesome (Charlie Somerville)" <charliesome@...>

27 messages 2013/05/07

[#54881] [ruby-trunk - Bug #8384][Open] Cannot build ruby against OpenSSL build with "no-ec2m" — "vo.x (Vit Ondruch)" <v.ondruch@...>

16 messages 2013/05/09

[#54921] [ruby-trunk - Bug #8393][Open] A class who's parent class is in a module can go wrong if files are required in the wrong order — "eLobato (Daniel Lobato Garcia)" <elobatocs@...>

15 messages 2013/05/12

[#54939] [ruby-trunk - Bug #8399][Open] Remove usage of RARRAY_PTR in C extensions when not needed — "dbussink (Dirkjan Bussink)" <d.bussink@...>

32 messages 2013/05/12

[#55053] [ruby-trunk - Feature #8426][Open] Implement class hierarchy method caching — "charliesome (Charlie Somerville)" <charliesome@...>

21 messages 2013/05/19

[#55096] [ruby-trunk - Feature #8430][Open] Rational number literal — "mrkn (Kenta Murata)" <muraken@...>

28 messages 2013/05/21

[#55197] [ruby-trunk - Feature #8461][Open] Easy way to disable certificate checking in XMLRPC::Client — "herwinw (Herwin Weststrate)" <herwin@...>

11 messages 2013/05/29

[ruby-core:55166] [ruby-trunk - Feature #8452][Open] Kernel#otherwise to rewrite code like (obj || default_obj).do_smth

From: "prijutme4ty (Ilya Vorontsov)" <prijutme4ty@...>
Date: 2013-05-26 11:41:58 UTC
List: ruby-core #55166
Issue #8452 has been reported by prijutme4ty (Ilya Vorontsov).

----------------------------------------
Feature #8452: Kernel#otherwise to rewrite code like (obj || default_obj).do_smth
https://bugs.ruby-lang.org/issues/8452

Author: prijutme4ty (Ilya Vorontsov)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


Imagine you have code like this 
    (long_computation_chain || []).do_smth
While it isn't difficult, but it forces a developer to use additional parentheses. It can be difficult to trace where opening bracket is when computation_chain is long. Due to this idiom code cannot be read or written left to right. This is the same problem as for 
    Hash[ *long_computation ]

So I propose a simple method Kernel#otherwise

    def otherwise(value, check = nil)
      if !check
        self || value
      else
        check.to_proc.call(self) ? self : value
      end
    end

So now one can write:
    long_computation_chain.otherwise([]).do_smth 
or
    long_computation_chain.otherwise('default', :empty?).do_smth
or
    long_computation_chain.otherwise('numbers not allowed', ->(x){ x.grep(/\d+/) }).do_smth



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