Few recent dmd pull requests

[H. S. Teoh via Digitalmars-d]

On Thu, Jun 26, 2014 at 10:38:53AM +0000, bearophile via Digitalmars-d wrote:
[...]
> --------------------
> 
> This proposes a __traits(documentation, expr):
> https://github.com/D-Programming-Language/dmd/pull/3531
> 
> Something similar is used in Python and Lisp, it allows to introspect
> the comments. It's useful for various generative purposes.
> 
> One quirk of this implementation, that I am not sure about:
> 
> >Comments will only be available if DMD is invoked with the "-D" flag.
> >If no comment is available for expr, __traits(comment, expr)
> >evaluates to the empty string.<

This is probably because without -D, the entire ddoc code doesn't even
run (which probably saves on compilation time), and comments are not
kept by the parser/lexer, so by the time the compiler evaluates
__traits(comment...), it doesn't know how to retrieve the comments
anymore.


[...]
> --------------------
> 
> https://github.com/D-Programming-Language/dmd/pull/3615
> 
> Will allow very handy, more DRY and less bug-prone like this:
> 
> // static array type
> int[$]   a1 = [1,2];    // int[2]
> auto[$]  a2 = [3,4,5];  // int[3]
> const[$] a3 = [6,7,8];  // const(int[3])
> 
> // dynamic array type
> immutable[] a4 = [1,2];    // immutable(int)[]
> shared[]    a5 = [3,4,5];  // shared(int)[]
> // partially specified part is unqualified.
> 
> // pointer type
> auto*  p1 = new int(3);  // int*
> const* p2 = new int(3);  // const(int)*
> 
> // mixing
> auto[][$] x1 = [[1,2,3],[4,5]];  // int[][2]
> shared*[$] x2 = [new int(1), new int(2)];  // shared(int)*[2]

I like this very much. I hope it will get merged in one form or another
eventually.


> A comment by Walter:
> 
> >My reservation on this is I keep thinking there must be a better way
> >than [$].<

Is the only objection one about syntax? Surely professional bikeshedders
like us can easily come up with more palatable syntaxes? ;-)


> --------------------
> 
> https://github.com/D-Programming-Language/dmd/pull/3638
> 
> Allows to write code like:
> 
> 
> void main() {
>     import std.algorithm;
>     alias sqr = a => a ^^ 2;
>     auto r = [1, 2, 3].map!sqr;
> }
> 
> 
> Currently you need to write:
> 
> alias F(alias f) = f;
> void main() {
>     import std.algorithm;
>     alias sqr = F!(a => a ^^ 2);
>     auto r = [1, 2, 3].map!sqr;
> }
[...]

What's wrong with just writing auto?

	auto sqr = a => a^^2;
	auto r = [1,2,3].map!sqr;


T

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