Re: DIP10005: Dependency-Carrying Declarations is now available for community feedback

[Andrei Alexandrescu via Digitalmars-d]

On 12/15/2016 02:22 PM, Timothee Cour via Digitalmars-d wrote:
Some more details on my proposa based on UDA:
// applies to next decl
@deps!({import std.algorithm;})
void test1(){}

// applies to a set of decls
@deps!({import std.stdio;}){
  void test2(){}
  void test3(){}
}

// applies to all following decls (':')
@deps!({import std.array;}):

// can specify other dependencies beyond imports and have arbitrary
complex logic:
@deps!({
  import std.range;
  static int[100] data2;
  version(linux){
    enum data1=import("foo");//string import
    pragma(lib, "curl");
  }
}):
void test4(){}

// Can alias some dependencies:
alias deps1=deps!({import std.algorithm;});

@deps1
void test4(){}

NOTE: the above code compiles if we add
`struct deps(T...){}`, but that logic would be implemented in the compiler.

I now understand the idea, thank you.

My question is, doesn't this take things too far? Earlier I wrote:

The acceptability of the proposal decays exponentially with its
deviation from existing import syntax.

Indeed adding less syntax is better, but that's not an absolute; the 
optimum isn't necessarily at the "zero syntax added" point. This is 
because there are several things to harmonize in language design, which 
naturally are in tension.


Andrei