Should I use alias or alias method

Question

I found a blog post on alias vs  alias method  As shown in the example given in that blog post  I simply want to alias a method to another within the same class  Which should I use  I always see alias used  but someone told me alias method is better   Usage of alias  class User    def full name     puts  Johnnie Walker    end    alias name full name end  User new name    gt Johnnie Walker   Usage of alias method  class User    def full name     puts  Johnnie Walker    end    alias method  name   full name end  User new name    gt Johnnie Walker   Blog post link here

User · Answer

A year after asking the question comes a new article on the subject:

http://erniemiller.org/2014/10/23/in-defense-of-alias/

It seems that "so many men, so many minds." From the former article author encourages to use alias_method, while the latter suggests using alias.

However there's a common overview of these methods in both blogposts and answers above:

use alias when you want to limit aliasing to the scope where it's defined
use alias_method to allow inherited classes to access it

User · Answer

The rubocop gem contributors propose in their Ruby Style Guide      Prefer alias when aliasing methods in lexical class scope as the   resolution of self in this context is also lexical  and it   communicates clearly to the user that the indirection of your alias   will not be altered at runtime or by any subclass unless made   explicit    class Westerner   def first name     names first   end   alias given name first name end      Always use alias method when aliasing methods of modules  classes  or   singleton classes at runtime  as the lexical scope of alias leads to   unpredictability in these cases   module Mononymous   def self included other      other class eval   alias method  full name   given name     end end  class Sting  lt  Westerner   include Mononymous end

User · Answer

I think there is an unwritten rule  something like a convention  that says to use  alias  just for registering a method-name alias  means if you like to give the user of your code one method with more than one name   class Engine   def start      code goes here   end   alias run start end   If you need to extend your code  use the ruby meta alternative   class Engine   def start     puts  start me    end end  Engine new start       gt  start me  Engine class eval do   unless method defined   run      alias method  run   start     define method  start  do       puts   before  extension        run         puts   after  extension      end   end end  Engine new start     gt   before  extension     gt  start me     gt   after  extension  Engine new run     gt  start me

User · Answer

A point in favor of alias instead of alias method is that its semantic is recognized by rdoc  leading to neat cross references in the generated documentation  while rdoc completely ignore alias method

User · Answer

alias method new method  old method  old method will be declared in a class or module which is being inherited now to our class where new method will be used   these can be variable or method both   Suppose Class 1 has old method  and Class 2 and Class 3 both of them inherit Class 1   If  initialization of Class 2 and Class 3 is done in Class 1 then both can have different name in Class 2 and Class 3 and its usage

User · Answer

Apart from the syntax  the main difference is in the scoping     scoping with alias method class User    def full name     puts  Johnnie Walker    end    def self add rename     alias method  name   full name   end  end  class Developer  lt  User   def full name     puts  Geeky geek    end   add rename end  Developer new name    gt   Geeky geek    In the above case method    name    picks the method    full name    defined in    Developer    class  Now lets try with alias   class User    def full name     puts  Johnnie Walker    end    def self add rename     alias name full name   end end  class Developer  lt  User   def full name     puts  Geeky geek    end   add rename end  Developer new name    gt   Johnnie Walker    With the usage of alias the method    name    is not able to pick the method    full name    defined in Developer   This is because alias is a keyword and it is lexically scoped  It means it treats self as the value of self at the time the source code was read   In contrast alias method treats self as the value determined at the run time   Source  http   blog bigbinary com 2012 01 08 alias-vs-alias-method html

User · Answer

alias method can be redefined if need be   it s defined in the Module class    alias s behavior changes depending on its scope and can be quite unpredictable at times   Verdict  Use alias method - it gives you a ton more flexibility   Usage   def foo    foo  end  alias method  baz   foo

[ruby] Should I use alias or alias_method?

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