On 7/24/2015 1:11 PM, Jonathan M Davis wrote:
On Friday, 24 July 2015 at 19:59:17 UTC, Shammah Chancellor wrote:
On Friday, 24 July 2015 at 19:45:55 UTC, Jonathan M Davis wrote:
On Friday, 24 July 2015 at 14:15:11 UTC, Shammah Chancellor wrote:
Since D has optional arguments -- why don't we support named parameters?
There are extremely handy and work beautifully in languages like C#.
We've argued about this several times in the past. We're not adding them.
They interact badly with overloading (especially if you try and add more
overloads later), and they make it so that the parameter names are part of
the API, which means even more bikeshedding and arguments about naming.
- Jonathan M Davis
Funny, they work beautifully in C#.
https://msdn.microsoft.com/en-us/library/dd264739.aspx
Well, I don't know how C# dealt with mixing function overloading with named
arguments (I haven't read the article yet)
Here's what it says:
-----------------
Use of named and optional arguments affects overload resolution in the following
ways:
•A method, indexer, or constructor is a candidate for execution if each of its
parameters either is optional or corresponds, by name or by position, to a
single argument in the calling statement, and that argument can be converted to
the type of the parameter.
•If more than one candidate is found, overload resolution rules for preferred
conversions are applied to the arguments that are explicitly specified. Omitted
arguments for optional parameters are ignored.
•If two candidates are judged to be equally good, preference goes to a candidate
that does not have optional parameters for which arguments were omitted in the
call. This is a consequence of a general preference in overload resolution for
candidates that have fewer parameters.
--------------------
D already has plenty enough overloading rules, UFCS, overloading templates with
non-templates, default values, constraints, overriding,
covariance/contravariance, auto ref, etc., enough to thoroughly confuse everyone
already :-)
