Ruby equivalent for Lua first-class functions?

ruby-talk
1

I think one of Lua's nice features is that all functions are first-
class functions. That makes it possible to override behavior like
this:

-- Sample stolen from Wikipedia
local oldprint = print -- Store current print function as
oldprint
print = function(s) -- Redefine print function
  if s == "foo" then
    oldprint("bar")
  else
    oldprint(s)
  end
end

How would you write the above sample using Ruby?

Grtz,
Francis

2

module Kernel
  alias_method :old_print, :print
  def my_print(*args)
    old_print "bar"
  end
  alias_method :print, :my_print
end

irb(main):017:0> print "hey"
bar
=> nil

There are several approaches to achieve the same, that's the beauty or
the curse of Ruby :slight_smile:

As more complex example, you can check how rubygems replace 'require'
functionality to be able to pick code outside the default $LOAD_PATH.

HTH,

···

On Nov 15, 12:12 pm, Dolazy <francis.ramme...@gmail.com> wrote:

I think one of Lua's nice features is that all functions are first-
class functions. That makes it possible to override behavior like
this:

-- Sample stolen from Wikipedia
local oldprint = print -- Store current print function as
oldprint
print = function(s) -- Redefine print function
if s == "foo" then
oldprint("bar")
else
oldprint(s)
end
end

How would you write the above sample using Ruby?

Grtz,
Francis

--
Luis Lavena