From: ts <decoux@...>
Date: 2001-06-16T20:58:47+09:00
Subject: [ruby-talk:16535] Re: Confusion about alias and alias_method

>>>>> "S" == Sean Russell <ser@germane-software.com> writes:

S> I don't quite understand this.

S> 	:anysymbol.inspect	# --> ":anysymbol"
S> 	id = :anysymbol
S> 	id.inspect		# --> ":anysymbol"

S> "inspect" is defined for Symbol, and it returns the same value as inspect 
S> called on a variable that holds a symbol (which is what happens in the Axe 
S> book, page 252).

 In page 252 of the book, id.inspect is used in an eval (i.e. in a string)
 and it do something like this (if :anysymbol.to_i == 9363)

   module_eval "alias_method :__9363__, :anysymbol"

 This is something perfectly valid.

 When you write

   id = :anysymbol
   alias_method  :__9363__, id.inspect

 ruby first call #inspect, which return the human representation of id
 which is ":anysymbol" and then it search the method associated with this
 string, i.e. it search the method :anysymbol which is not defined.

 To have the equivalent with the example given in p 252 you must write
 something like this

   module_eval "alias_method :#__{id.to_i}__, id.inspect"


Guy Decoux