On Sunday, February 8, 2015 at 5:45:55 PM UTC-8, Dominique Orban wrote:
>
> I'm writing a function that takes optional arguments. Many of them must be
> arrays of a certain size. I'd like to perform a quick check of their size
> at the top of the function and thought it would be a good use case for meta
> programming, but I can't seem to get the syntax right. Here's an example
> that hopefully illustrates what I'm trying to do:
>
> function test(a; x=zeros(5), y=zeros(5))
> for arg in {:x, :y}
> if length(eval(arg)) != 5 # ERROR: x not defined
> error(@eval $(string(arg, " must have length 5")))
> end
> end
> # ...
> end
>
You don't need or want eval here. I would just do
for arg in (x,y)
length(arg) == 5 || error("optional arguments must have length 5")
end
