On 12/30/16 7:32 PM, Chris Wright wrote:
On Fri, 30 Dec 2016 22:42:39 +0000, Stefan Koch wrote:
On Friday, 30 December 2016 at 22:29:18 UTC, Chris Wright wrote:
* Performance improvements, primarily when a module imports another,
bulky module for optional functionality.
That is solved by selective imports.
Well, not today, but it could be. Same with static imports. Both
accomplish this goal better than DIP1005.
Is this fact or opinion? If the former, could you please point where
DIP1005 is getting it wrong. Thanks.
* Making it easier to locate where things are defined when reading
code.
That is solved by selective imports.
Static imports do that better than selective imports, though it's more
typing.
So whether that's overall better is not settled, is it? We can't really
define "better" as whatever each participant believes.
With selective imports, you can either find the declaration in the
current module, or find the symbol in an import list. If it's imported,
and the module author is using standard code formatting, you will find
the import at the top of the module, which will be fast. This is less
true with arbitrarily scoped imports.
With DIP1005, you rely on there also being selective or static imports.
If the module author didn't use them, then you have to pull out grep.
DIP1005 allows the declaration to encapsulate its own dependencies. Of
course if top-level imports are also present, the benefit erodes.
* Making it easier to move declarations between files.
That is solved by selective imports.
That helps a bit. You still need to exercise discipline in only using
selective imports for what you need for visible declarations.
Static imports work about as well, except you can probably write a
complicated regex replacement to extract out the imports you need.
DIP1005 is a solid improvement here.
Unfortunately, this is a rather marginal usecase.
-- Another thing that just occurred to me: if you're modifying a function
signature and that brings in another imported symbol, you don't have to
move to the top of the file or struct to add the necessary import. It's a
small thing for vim users, who are used to using marks and fast movement
commands, but if you're using, say, VSCode, that might be painful.
That's one of the many benefits of encapsulation.
Andrei
