chaining
Brian
digitalmars at brianguertin.com
Fri Feb 27 03:02:10 PST 2009
On Thu, 26 Feb 2009 09:45:28 +0100, grauzone wrote:
> Brian wrote:
>> I want to use a chaining system for easy setting of object attributes,
>> which would work great for a single object, unfortunately derived
>> classes cannot inherit the chained functions implicitly, whats the best
>> way around this?
>>
>> class Base {
>> int x;
>> Base foo(int x_) {
>> this.x = x_;
>> return this;
>> }
>> }
>>
>> class Derived : Base {
>> Derived bar(int y_) {
>> return this;
>> }
>> }
>>
>> // usage:
>> auto m = (new Derived).foo(10).bar(x); // bar can be accessed through
>> foo
>
> Couldn't you just write the above example as:
>
> auto m = new Derived;
> m.foo(10);
> m.bar(x);
>
> This is actually much more readable: the reader doesn't need to know
> that the functions foo and bar return m; instead, the code uses m
> directly. Obviously, this is also simpler to implement than chaining.
>
> I don't get why some people like chaining. Unlike in languages like C++,
> you can always use "auto" to keep the typing to a minimum. What more
> arguments are there for chaining?
your probably right.. it also looks simpler written out.
i do sort of use chaining to create dictionaries of variant/box objects,
though it could probably just be a function with variable arguments. i
think it looks neat.
sig.emit((new Message)
("number", 24)
("str", "hello")
("obj", someobject)
("and-so-on", [1,2,3])
);
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