use a module method for traittype

Author: rafaqz

src/fallbacks.jl

@@ -112,28 +112,15 @@ coordinates(t::AbstractFeatureCollectionTrait, fc) = [coordinates(f) for f in ge
 Base.convert(T::Type, ::AbstractGeometryTrait, geom) = error("Conversion is enabled for type $T, but not implemented. Please report this issue to the package maintainer.")
 
 # Package level `GeoInterface.convert` method
-# We convert Module to `Val{nameof(module)}` so that packages can use dispatch.
-# This is a slight hack: there can theoretically be multiple
-# packages with the same name and different UUIDs. We just ignore this possibility.
-# Whichever package has the name first in the main julia registry is canonical.
+# Packages must implement their own `traittype` method
+# that accepts a GeoInterface.jl trait and returns the
+# corresponding geometry type
 convert(package::Module, geom) = convert(Val{nameof(package)}(), geom)
 function convert(package::Val, geom)
     t = trait(geom)
-    convert(traittype(package, t), t, geom)
+    convert(package.traittype(t), t, geom)
 end
 
-
-
-"""
-    traittype(package::Module, trait::AbstractTrait)
-    traittype(package::Val{:PackageName}, trait::AbstractTrait)
-
-Return the object type for a trait and a package.
-"""
-function traittype end
-traittype(mod::Module, trait::AbstractTrait) = 
-    traitype(Val{nameof(mod)}(), trait)
-
 # Subtraits
 
 """

src/interface.jl

@@ -605,9 +605,13 @@ coordinates(obj) = coordinates(trait(obj), obj)
 
 """
     convert(type::CustomGeom, geom)
+    convert(module::Module, geom)
 
 Convert `geom` into the `CustomGeom` type if both geom as the CustomGeom package
 have implemented GeoInterface.
+
+Can also convert to a `Module`, which finds the corresponding
+type for the trait using the modules `traittype` method.
 """
 convert(T, geom) = convert(T, geomtrait(geom), geom)