PR #22 is breaking... should a major release be issued?

[alex-s-gardner]

#22 is breaking.

using GeoFormatTypes v0.4.1

julia> epsg = GeoFormatTypes.EPSG(4326)
EPSG(4326)

julia> GeoFormatTypes.EPSG(epsg)
EPSG(4326)

julia> typeof(epsg) == GeoFormatTypes.EPSG
true

using GeoFormatTypes v0.4.2

julia> epsg = GeoFormatTypes.EPSG(4326)
EPSG{1}((4326,))

julia> GeoFormatTypes.EPSG(epsg)
ERROR: MethodError: no method matching EPSG(::EPSG{1})

Closest candidates are:
  EPSG(::AbstractString)
   @ GeoFormatTypes ~/.julia/packages/GeoFormatTypes/UFNTK/src/GeoFormatTypes.jl:319
  EPSG(::Tuple{Vararg{Int64, N}}) where N
   @ GeoFormatTypes ~/.julia/packages/GeoFormatTypes/UFNTK/src/GeoFormatTypes.jl:316
  EPSG(::Int64...)
   @ GeoFormatTypes ~/.julia/packages/GeoFormatTypes/UFNTK/src/GeoFormatTypes.jl:318
  ...

Stacktrace:
 [1] top-level scope
   @ REPL[6]:1

julia> typeof(epsg) == GeoFormatTypes.EPSG
false

[rafaqz]

@evetion can we bring back that constructor?

[evetion]

Yeah, I will make a PR. Although it seems like a weird API, did anyone use it as such?

[rafaqz]

I cant remember intentionally doing that. Did it call convert or somrthing?

[evetion]

@alex-s-gardner Do you actually call EPSG(::EPSG), or test for type equality? I'm sorry if we broke your code. While technically breaking (the type signature), we thought we could get away with it, as I made sure the tests stayed green. Also:

julia> a = EPSG(4326)

julia> typeof(a) <: GeoFormatTypes.EPSG
true

julia> a isa GeoFormatTypes.EPSG
true

---

I cant remember intentionally doing that. Did it call convert or somrthing?

Yeah, it recognized EPSG requires an Int and EPSG can convert to that directly. Doesn't seem to work out of the box for NTuples though.

[rafaqz]

Oh right its still actually an EPSG just not exactly the type. I misunderstood the comparison.

Thats not actually breaking, type parameter equality is not promised.

This is the reason to use <: rather than == for types

[alex-s-gardner]

OK, I used both of these in FastGeoProjections but if they are not considered breaking then we're all good.

[alex-s-gardner]

How does one assert function input to be a subtype of?

source_epsg :: EPSG

I would have thought something like
source_epsg:: <: EPSG
of
source_epsg:: <: EPSG

but neither work and searching has proven fruitless

[evetion]

Exactly like you want:

function do_thing(source_epsg::EPSG)

Although I do sometimes try to write <:, but that's only for parametric types in methods.

You can derive this logically:
do_thing(something) equals do_thing(something::Any) and 1 isa Any == true and typeof(1) <: Any == true.

Documentation is here.