On 2012-04-06 08:47, Walter Bright wrote:
On 4/5/2012 5:00 AM, Manu wrote:
> C# and Java both have attributes, following these established design
patterns, I
> don't think there should be any mystery over how they should be
implemented.
I was thinking of something along the lines of what has been proposed
here earlier:
@attr(identifier = expression)
as a storage class, like:
@attr(foo = bar + 1) int x;
and then:
__traits(hasAttribute, x, foo)
would return true, and:
__traits(getAttribute, x, foo)
would return the expression (bar+1). The expression would be
compile-time only, evaluated at the point of declaration.
The implementation is simple enough, just attach to each symbol an array
of (identifier,expression) pairs.
You could also omit the expression, and just have:
@attr(bar) int y;
I'm not a particular fan of that syntax. I would go with:
@identifier(key = value/expression)
Like:
@foo(k1 = bar + 1, k2 = bar + 2) int x;
If the attribute takes one key-value pair:
@foo(value = bar + 1) int x;
Can be shortened like:
@foo(bar + 1) int x;
And for attributes that don't take any values:
@foo int x;
--
/Jacob Carlborg
