[julia-users] Re: Do `let` blocks enable compiler optimization of "local" variables?

[Cristóvão Duarte Sousa]

Well, I guess this partially answers my own question:

a = 0
println(typeof([a for i=1:10]))

function f()
    a = 0
    println(typeof([a for i=1:10]))
end
f()

let
    a = 0
    println(typeof([a for i=1:10]))
    b = 0
    println(typeof([b for i=1:10]))
end

outputs

Array{Any,1}
Array{Int64,1}
Array{Any,1}
Array{Int64,1}

So, it's not the same (unless one takes care of declaring variables as 
local)...

On Friday, June 13, 2014 11:44:30 AM UTC+1, Cristóvão Duarte Sousa wrote:
>
> According to the performace tips, code must be inside functions and 
> variable must be local for better optimization.
>
> In IJulia notebook I usually put critical code inside dummy functions, 
> something like
>
> function f()
>     # variables and code here
> end
> f()
>
> I wonder if doing the visually nicer
>
> let
>     # variables and code here
> end
>
> would provide the same benefits?
>
>
>