Any chance to call Tango as Extended Standard Library

[Andrei Alexandrescu]

Lars Ivar Igesund wrote:
> Andrei Alexandrescu wrote:
> 
>> Lars Ivar Igesund wrote:
>>> Andrei Alexandrescu wrote:
>>> 
>>>> For example, I'm not sure how code in std.algorithm could help 
>>>> containers or streams in Tango (as it should), or how to
>>>> reconcile std.algorithm with std.core.array.
>>> If the language (D2++) will have a new way of iteration and
>>> ranges known and enforced by the compiler, then I expect Tango to
>>> support those at some point, and std.algorithm would presumably
>>> just work. However, if it is based on some interface, ad hoc
>>> (these methods must be present) or properly via an interface
>>> Range { }, I would expect Tango developers to be involved in the
>>> process of defining those interfaces (if Tango is meant to
>>> use/know about them). Since I have seen neither, it is somewhat
>>> difficult to make a well informed comment on the subject.
>> It's been there for a while now (since 25 Nov 2008).
>> 
>> http://www.digitalmars.com/d/2.0/statement.html#ForeachStatement
>> 
>> Scroll down to "Foreach over Structs and Classes with Ranges". The 
>> changelog reflects that too:
>> 
>> http://www.digitalmars.com/d/2.0/changelog.html
>> 
>> Version 2.021 mentions "Added range support to foreach statement."
> 
> Ah, thanks :)
> 
> However, replacing the "single" opApply with 5 properties seems
> somewhat excessive? At least it becomes even more obvious that a form
> of (runtime queryable) struct interfaces will be necessary - the one
> and only feature I really really want in D2.

opApply was very inefficient and defining an abstraction that allows 
efficient iteration was a key goal of range design and foreach overhaul. 
Using duck typing and implicit interfaces was a tried and true 
technique. On top of this framework it is easy to define and use 
explicit interfaces. Using classic interfaces would have hamstrung 
efficiency of iteration from day one.

I'd be curious to find out more about a runtime queryable struct 
interface. How would it work? What idioms would it enable?


Andrei