Damjan Rems wrote:
> 
> I am just wondering is there any differnece between these two
> techniques.
> 
> There is file.rb
> 
> 1. use load to execute contents of file.rb
> load "file.rb"
> 
> 2. use eval to execute contents of file.rb
> c = File.open('file.rb') {|f| f.read }
> eval(c)
> 
> Load is more conventional but eval is more flexible (source can be
> modifyed before evaluated).
> 
> Are there any hidden gotchas?
> 
> 
> by
> TheR

Yes, there IS a difference, and yes, there ARE gotchas.

1. The load way:
module Alpha
  load 'file.rb'
end
class Beta
  load 'file.rb'
end
class Gamma
  include Alpha
end

2. The eval way:
module Alpha
  c = File.open('file.rb') {|f| f.read }
  eval c
end
class Beta
  c = File.open('file.rb') {|f| f.read }
  eval c
end
class Gamma
  include Alpha
end

In 1., the contents of file.rb are loaded in *global* namespace. But 
that's not the whole story. When file.rb defines a method my_method, 
you'll end up with *four* methods: a public main#my_method, a private 
Alpha#my_method, a private Beta#my_method and a private Gamma#my_method. 
Not quite a "least surprise".

2.'s behaviour is more intuitive. You'll get a public Alpha#my_method, a 
public Beta#my_method and a public Gamma#my_method. But if file.rb has 
any load (or require) of its own, that stuff will be loaded in your 
script's global namespace...

And there's my problem. I'm using two different libraries both 
containing (directly or indirectly) modules or classes with the same 
name. To avoid name conflicts, I would like my script to wrap them (or 
at least one of them) in their own namespace. But such a thing seems to 
be impossible if those modules/classes are placed far away in a long 
chain of required libraries. Is there any way out of this library hell?
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