On Wed, May 30, 2018 at 1:52 PM Chris Angelico
On Thu, May 31, 2018 at 1:23 AM, Peter O'Connor
wrote: In comparison, I think that := is much simpler.
In this case that's true, but a small modification:
updates = { y: do_something_to(potential_update) for x in need_initialization_nodes for y in [x, *x.synthetic_inputs()] if potential_update is not None given potential_update = command.create_potential_update(y) }
Shows the flexibility of this given syntax vs ":="
I don't understand what you're showcasing here. With :=, you give a name to something at the exact point that it happens:
updates = { y: do_something_to(potential_update) for x in need_initialization_nodes for y in [x, *x.synthetic_inputs()] if (potential_update := command.create_potential_update(y)) is not None }
Personally, I'd use a shorter name for something that's used in such a small scope (same as you use one-letter "x" and "y"). But that's the only way that the 'given' syntax looks at all better - by encouraging you to use yet another line, it conceals some of its immense verbosity. (Note how the name "potential_update" is used twice with :=, once to set and one to retrieve; but with given, it's used three times - retrieve, retrieve, and set.)
How does this show that 'given' is more flexible?
Oh yeah, good point, I forgot that I could use := within the condition itself. It does show that this feature is useful, but not that given is more flexible than :=.
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