Expose resolver to load (#197)

* Add type assertions for function arguments in `src/composer.jl`.

* Add missing type annotations.

* Expose resolver to the function `load`. This is required to inform a resolver when loading by users.

src/YAML.jl

@@ -57,15 +57,18 @@ function _patch_constructors(more_constructors::_constructor, dicttype::_dicttyp
     return more_constructors
 end
 
-
 """
     load(x::Union{AbstractString, IO})
 
 Parse the string or stream `x` as a YAML file, and return the first YAML document as a
 Julia object.
 """
-load(ts::TokenStream, constructor::Constructor) =
-    construct_document(constructor, compose(EventStream(ts)))
+function load(tokenstream::TokenStream, constructor::Constructor)
+    resolver = Resolver()
+    eventstream = EventStream(tokenstream)
+    node = compose(eventstream, resolver)
+    construct_document(constructor, node)
+end
 
 load(input::IO, constructor::Constructor) =
     load(TokenStream(input), constructor)

src/composer.jl

@@ -27,8 +27,8 @@ mutable struct Composer
     resolver::Resolver
 end
 
-function compose(events::EventStream)
-    composer = Composer(events, Dict{String, Node}(), Resolver())
+function compose(events::EventStream, resolver::Resolver)
+    composer = Composer(events, Dict{String, Node}(), resolver)
     @assert forward!(composer.input) isa StreamStartEvent
     node = compose_document(composer)
     if peek(composer.input) isa StreamEndEvent