Stephen,
Thanks! The "let" translation below makes it clear.
Is there an explanation of the semantics of Julia at that level of detail
somewhere? I wasn't able to find anything like this in the manual.
I like Julia a lot, but one of my concerns is a lack of precision in the
documentation and apparent lack of a written language definition. Or maybe
I just haven't found the right sections/documents.
On Friday, May 6, 2016 at 6:40:41 PM UTC-7, Steven G. Johnson wrote:
>
>
>
> On Friday, May 6, 2016 at 2:18:42 PM UTC-4, David Dill wrote:
>>
>> It's a bit surprising that, if d1 is mentioned for the first time in d1 =
>> d2 = Dict() in f7 below, the inferred type of d1 is different from the
>> inferred type of d2, especially since the inferred type is different in d8.
>>
>
> The type of d2 isn't inferred -- you explicitly declared it as
> Dict{Int,Int} in the line above.
>
> As for d1, the key thing to remember is that the value of an assignment
> operation is equal to the *right-hand* side. That is, in a=b=c, c is
> assigned to both a and b. More explicitly, in your example, d1 = d2 =
> Dict() is equivalent to
>
> let temp = Dict() # gives a Dict{Any,Any}
> d2 = temp # requires a conversion (hence a copy) since d2 was
> declared as Dict{Int,Int}
> d1 = temp # since d1's type was not declared, it is inferred to
> be that of temp, hence no copy is needed
> end
>
