On Fri, 2016-07-22 at 01:02, Marius Millea <[email protected]> wrote:
>> FYI Mauro's package has something similar
>> <http://parametersjl.readthedocs.io/en/latest/manual/>.
>>
>
> Some interesting stuff in there, thanks!
The problem with your `@self` and with Parameters.jl's
`@unpack_SomeType` macros is that it is easy to introduce bugs.
Consider:
type A # and register it with @self
a
end
@self f(x,aa:A) = sin(2pi/a*x)
Sometime later you refactor type A:
type A
a
pi
end
now your function f is broken. So, for every change in type A you need
to check all functions which use `@self`.
Instead I now use the @unpack macro (and its companion @pack), also part
of Paramters.jl. Then above f becomes
function f(x,aa::A)
@unpack aa: a
sin(2pi/a*x)
end
This is still much more compact than writing out all the aa.a, etc. (if
there are lots of field accesses) but safe. Also, it clearly states, at
the top of the function, which fields of a type are actually used.
