Please change alias ReplaceArrayWithPointer = Flag!"replaceArrayWithPointer"

The correct idiom involving Flag is: * Use the name Flag!"frob" for the type of the flag * Use Yes.frob and No.frob for the flag values * Do NOT alias Flag!"frob" to a new name. This is unnecessary, unhelpful, and wasteful. Can somebody please change the respective code in std.experimental.ndslice? Thanks, Andrei

On Thursday, 21 January 2016 at 19:31:19 UTC, Andrei Alexandrescu wrote: > The correct idiom involving Flag is: > > * Use the name Flag!"frob" for the type of the flag > > * Use Yes.frob and No.frob for the flag values > > * Do NOT alias Flag!"frob" to a new name. This is unnecessary, unhelpful, and wasteful. > > Can somebody please change the respective code in std.experimental.ndslice? > > > Thanks, > > Andrei OK --Ilya

On Thursday, 21 January 2016 at 19:31:19 UTC, Andrei Alexandrescu wrote: > * Do NOT alias Flag!"frob" to a new name. This is unnecessary, unhelpful, and wasteful. I disagree. Making an alias means the user does not have to import std.typecons in their code, and as a purely subjective measure, ReplaceArrayWithPointer.Yes looks better than Flag!"replaceArrayWithPointer".Yes.

On Thursday, 21 January 2016 at 20:42:56 UTC, jmh530 wrote: > On Thursday, 21 January 2016 at 19:31:19 UTC, Andrei Alexandrescu wrote: >> The correct idiom involving Flag is: >> >> * Use the name Flag!"frob" for the type of the flag >> >> * Use Yes.frob and No.frob for the flag values >> >> * Do NOT alias Flag!"frob" to a new name. This is unnecessary, unhelpful, and wasteful. >> >> Can somebody please change the respective code in std.experimental.ndslice? >> >> >> Thanks, >> >> Andrei > > Perhaps > https://dlang.org/phobos/std_typecons.html#.Flag > should be adjusted. It recommends aliasing. https://github.com/D-Programming-Language/phobos/pull/3947

January 21, 2016

Re: Please change alias ReplaceArrayWithPointer = Flag!"replaceArrayWithPointer"

Posted by H. S. Teoh
in reply to Jack Stouffer

Permalink

H. S. Teoh

Posted in reply to Jack Stouffer

Permalink

On Thu, Jan 21, 2016 at 08:42:17PM +0000, Jack Stouffer via Digitalmars-d wrote:
> On Thursday, 21 January 2016 at 19:31:19 UTC, Andrei Alexandrescu wrote:
> >* Do NOT alias Flag!"frob" to a new name. This is unnecessary, unhelpful, and wasteful.
> 
> I disagree. Making an alias means the user does not have to import std.typecons in their code, and as a purely subjective measure, ReplaceArrayWithPointer.Yes looks better than Flag!"replaceArrayWithPointer".Yes.

Yeah, and it looks even worse in function signatures, especially when default arguments are present:

	auto myFunc(T)(T data, Flag!"replaceArrayWithPointer" replaceArrayWithPointer = Flag!"replaceArrayWithPointer".Yes)
	{ ... }

vs.

	alias ReplaceArrayWithPointer = Flag!"replaceArrayWithPointer";
	auto myFunc(T)(T data, ReplaceArrayWithPointer replaceArrayWithPointer = ReplaceArrayWithPointer.Yes)
	{ ... }

Still pretty bad, but at least it's a few characters less.

On a tangential note, default arguments seriously should allow abbreviated syntax, to prevent the blatant violation of DRY as shown above:

	auto myFunc(T)(T data, ReplaceArrayWithPointer replaceArrayWithPointer = .Yes)
	{ ... }

Basically, inside a default argument spec, it should be as though the delcaration were encased in a `with(T) { ... }` block where T is the type of the argument.

Even better would be a way to not have to type out the variable name when it is just the type name camelcased, but I haven't thought of a way of doing this that fits in with D's current syntax just yet.  Some manner of "eponymous variable", along the same idea as eponymous templates.

T

-- 
Programming is not just an act of telling a computer what to do: it is also an act of telling other programmers what you wished the computer to do. Both are important, and the latter deserves care. -- Andrew Morton

On 01/21/2016 04:58 PM, H. S. Teoh via Digitalmars-d wrote: > auto myFunc(T)(T data, Flag!"replaceArrayWithPointer" replaceArrayWithPointer = Flag!"replaceArrayWithPointer".Yes) > { ... } auto myFunc(T)(T data, Flag!"replaceArrayWithPointer" flag = Yes.replaceArrayWithPointer) Andrei

On 01/21/2016 03:42 PM, Jack Stouffer wrote: > On Thursday, 21 January 2016 at 19:31:19 UTC, Andrei Alexandrescu wrote: >> * Do NOT alias Flag!"frob" to a new name. This is unnecessary, >> unhelpful, and wasteful. > > I disagree. Making an alias means the user does not have to import > std.typecons in their code, and as a purely subjective measure, > ReplaceArrayWithPointer.Yes looks better than > Flag!"replaceArrayWithPointer".Yes. That would be Yes.replaceArrayWithPointer. -- Andrei

Forums