Few recent dmd pull requests

[Shammah Chancellor via Digitalmars-d]

On 2014-06-26 10:38:53 +0000, bearophile said:

> For people that are not following closely what's happening in GitHub, 
> there are some nice or very nice patches waiting to be fixed and/or 
> accepted, among the last ones:
> 
> --------------------
> 
> 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.<
> 
> --------------------
> 
> Optional monitors for class instances, including a fallback:
> https://github.com/D-Programming-Language/dmd/pull/3547
> 
> It was discussed in this newsgroup too. Beside the little save in 
> memory (probably small), monitors today are not much appreciated. 
> Andrei seemed to agree with this idea.
> 
> --------------------
> 
> 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*[$] x2 = [new int(1), new int(2)];  // shared(int)*[2]
> 
> 
> A comment by Walter:
> 
>> My reservation on this is I keep thinking there must be a better way than [$].<
> 
> --------------------
> 
> 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;
> }
> 
> --------------------
> 
> https://github.com/D-Programming-Language/dmd/pull/3679
> 
> This introduces __traits(valueRange, expr), and I think it introduces 
> range values to the ?: expressions too.
> 
> The __traits(valueRange, expr) is meant to be useful for debugging 
> range values, that is meant to be improved in future. Currently this 
> patch seems stalled because Lionello seems to not provide few small 
> things Walter has asked.
> 
> --------------------
> 
> https://github.com/D-Programming-Language/dmd/pull/3680
> 
> 
> It should fix this bug:
> 
> void main() {
>      int[int][int] a1 = cast()[1: [2: 3]]; // workaround
>      int[int][int] a2 =       [1: [2: 3]]; // error
> }
> 
> 
> And will allow you to write:
> 
> void main() {
>      import std.bigint;
>      BigInt[] data = [-5, 6, 9];
> }
> 
> 
> Currently in D you have write this:
> 
> void main() {
>      import std.bigint;
>      auto data = [BigInt(-5), BigInt(6), BigInt(9)];
> }
> 
> 
> Or this (writing -5.BigInt is generally not a good idea):
> 
> void main() {
>      import std.bigint;
>      auto data = [BigInt(-5), 6.BigInt, 9.BigInt];
> }
> 
> --------------------
> 
> Bye,
> bearophile


Some of those fix some very annoying and long standing bugs.   Whoot.

-Shammah