It bugs me, but only a little, so I won't lose sleep over it :)
Then again, I wish Julia had a "strict" mode. In strict mode, the language
would be more pure mathematically, e.g. scalars have no indices, the
transpose of a vector is a covector, etc. This bit me recently because if T
<: U, then Array{T} is NOT <: Array{U} although as, sub-modules
<https://en.wikipedia.org/wiki/Module_(mathematics)>, Tmodule <: Umodule.
Then again, as I'm learning, if we want Julia to do something bad enough,
e.g. have a "strict" mode, we can have it. For example, I could write a
package "strict.jl" where
using strict
would kill Base.getindex(::Number) and things like that. That could be cool
:)
On Wednesday, December 2, 2015 at 9:38:50 AM UTC+8, Tim Holy wrote:
>
> On Tuesday, December 01, 2015 03:19:33 PM Eric Forgy wrote:
> > A scalar is distinct from a vector so size(a) = () makes sense. getindex
> for
> > a scalar does not make sense and should probably be removed on the
> grounds
> > of mathematical elegance :) Any code that depends on referencing a
> scalar
> > via an index is probably flawed in the first place.
>
> Conversely, there are many people who seem to want Julia to treat scalars
> and
> 1-vectors indistinguishably (ala Matlab).
>
> For what it's worth, here's a (contrived) example to justify the current
> behavior:
>
> function sum_over_dims(A, dims)
> for d in dims
> A = sum(A, d)
> end
> A
> end
>
> sum_over_dims(A, [2,3])
> sum_over_dims(A, 2)
>
> Why should I write sum_over_dims(A, [2]) in the latter case?
>
> Best,
> --Tim
>
>
