In coffee script i have this little code snippet.
class Collection
construct:(@collection=[])
Now i want to access that object as if it was an array but i want to get the collection variable when i do so. In other languages i would implements an ArrayAccess of some type and code the next, current etc methods
obj= new Collection([1,2,3])
obj[0] # this should equal 1
How can i do this in javascript or coffeescript either will do
That's impossible. You would need some kind of proxy for that. There is no "ArrayAccess" declaration feature, as bracket notation is just property access on your Collection instance (like obj["collection"]).
Instead, you can:
implement a getter function, like
class Collection
construct:(@collection=[])
at: (i) ->
@collection[i]
obj.at 0 # 1
use the Collection object itself as a holder of the elements (like e.g. jQuery does it). You loose the native array features, though. You might even subclass Array to some extent (.length does not update automatically).
class Collection
constructor: (col = []) ->
@length = 0
for el in col
Array::push.call(@, el)
obj[0] # 1
