Note that you can also write this as

julia> s = Set([2,3,1])
Set([2,3,1])

julia> 2 in s
true

julia> s in 2
false

Which might make it easier to understand why the second one fails.

Cheers,
   Kevin


On Mon, Aug 29, 2016 at 3:00 PM, Erik Schnetter <[email protected]> wrote:

> On Mon, Aug 29, 2016 at 3:59 PM, Jared Crean <[email protected]> wrote:
>
>> Here is an oddity:
>>
>> julia> s
>> Set([2,3,1])
>>
>> julia> in(s, 2)
>> false
>>
>> julia> in(2, s)
>> true
>>
>> I would have though the first use of in would be an error because asking
>> if a set is contained in a number is not defined.  Is there some other
>> interpretation of the operation?
>>
>
> In Julia, every number is a collection that contains just this number.
> Thus you are essentially asking whether the set `s` is equal to this
> number, which it is not.
>
> -erik
>
> On Monday, August 29, 2016 at 3:27:30 PM UTC-4, Jared Crean wrote:
>>>
>>> Ah, yes.  That's it.
>>>
>>>   Thanks,
>>>     Jared Crean
>>>
>>> On Monday, August 29, 2016 at 3:11:02 PM UTC-4, Erik Schnetter wrote:
>>>>
>>>> Jared
>>>>
>>>> Are you looking for the function `in`?
>>>>
>>>> -erik
>>>>
>>>> On Mon, Aug 29, 2016 at 3:06 PM, Jared Crean <[email protected]> wrote:
>>>>
>>>>> I'm looking for a data structure that allows O(1) querying if a value
>>>>> is contained in the data structure, and reasonably fast construction of 
>>>>> the
>>>>> data structure given that the initial size is unknown (although this
>>>>> criteria is not that strict).  I was looking at the Set in base, but I
>>>>> can't find a way to test if a Set contains contains a particular value.  I
>>>>> also don't know about the efficiency of appending to a Set.  Any
>>>>> suggestions or information about Set would be appreciated.
>>>>>
>>>>>     Jared Crean
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Erik Schnetter <[email protected]> http://www.perimeterinstitute.
>>>> ca/personal/eschnetter/
>>>>
>>>
>
>
> --
> Erik Schnetter <[email protected]> http://www.perimeterinstitute.
> ca/personal/eschnetter/
>

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