Warning: I don’t really know what I’m talking about so if I make any
mistakes in terminology, please try to correct me…
I've been doing a lot of Python programming and I've discovered that
it’s actually a very powerful language. The language, itself, lacks any
kind of elegance but it has all the power of Ruby and a little more
performance. It also has a richer set of libraries, although not in all
One thing that Ruby should take from Python are continuations.
is moving away from list creation and version 3.0 functions will return
Python iterators, implemented with continuations, instead of actual
since they are not used nearly as much as you might think.
The reason why I say that Ruby needs continuations is because they
more versatile than Ruby iterators. The reason why I say that is
you can make Ruby iterators with continuations but you can’t make
continuations with Ruby iterators. This means that you can implement a
continuation iterator and Object class can automatically define a Ruby
iterator based on your continuation iterator. After all, Ruby iterators
nice. I’m surprised by how annoyed I am that Python for loops don’t
One weakness of Ruby iterators that continuations don’t have is
iteration. If you have two containers that represent different aspects
the same things, it’s difficult to iterate over both of them in Ruby.
Python, you can do this:
list1 = [1, 2, 3, 4]
list2 = [‘a’, ‘b’, ‘c’, ‘d’]
Okay, Python is more wordy than I’d like
I could have just used zip() but you rarely need the list!
for num, letter in itertools.izip(list1, list2):
# Do something with both numbers and letters
print num, letter
How would one do this in Ruby? You can use .each_with_index and
the other list but that assumes that the other list is indexable, which
happens to be true of arrays but is not true in general. I’ve thought
implementing some Ruby equivalent of zip() (or preferably izip()) and
discovered that I can’t do so without continuations.
…Hence, my post. I’m actually at odds with Pythonic philosophy.
idea that there should only be one way to do things is ludicrous and a
constant up hill battle. One thing that Python does right is that it’s
afraid to “steal” from other languages and that’s the right attitude to
have. Adopt whatever is useful!
Python 3.0 looks like great language. I’m hoping that Ruby 2.0 will
even better 'cause, frankly, Ruby is more fun to program in…