On Monday, May 18, 2015 at 5:31:18 PM UTC-4, Yichao Yu wrote:
>
> On Mon, May 18, 2015 at 5:24 PM, Scott Jones <[email protected]
> <javascript:>> wrote:
> > I suppose I could use a set simply to determine if it was present or
> not,
> > and then push! to another array if not present... just didn't seem as
> > efficient as what I'm used to...
>
> Why does it have to be an array? And what data structure do you use in
> other languages?
>
In COS (CachéObjectScript... i.e. 21st century Mumps), I would have written
something like:
If '$data(arr(key),index) { // If the array already has the key, it is set
into the variable index, otherwise:
Set arr(key) = $Increment(index) // atomically increment index, and set
the key to that value in the array
}
// Do whatever I want with the index (usually I also set up a reverse
mapping, i.e.:
Set index(index) = key
The nice thing in COS, all I have to do to make that persistent, and shared
across a system (or also distributed to other systems), is add a "^" before
the arrays or values...
`^arr(key)` and `$increment(^index)` and `^index(^index)`.
Very very fast too...
> >
> > On Monday, May 18, 2015 at 4:53:02 PM UTC-4, Jameson wrote:
> >>
> >> use a Set?
> >> http://docs.julialang.org/en/latest/stdlib/collections/?highlight=set
> >>
> >> On Mon, May 18, 2015 at 4:46 PM Scott Jones <[email protected]>
> wrote:
> >>>
> >>> I would like to be able to do the following in Julia:
> >>> Take a UInt64 (or UInt128, for that matter), and add it to an array,
> if
> >>> it is not already present, returning the index.
> >>> (This would be trivial in the language I used to work on, and I think
> it
> >>> probably is in Julia as well, but I haven't found the right data
> structure
> >>> yet...)
> >>> What would be the best performing way of handling that?
> >>> What if, instead of an UInt64 or UInt128, I had an array of bytes
> (like
> >>> 128 or 256)? What would be the best way for that?
> >>>
> >>> Thanks, Scott
>
