Fix call to internal function kwarg_decl for Julia 1.4, fixes #82.

Author: fredrikekre

src/utilities.jl

@@ -293,17 +293,17 @@ kws = keywords(f, first(methods(f)))
 ```
 """
 function keywords(func, m::Method)
-    local table = methods(func).mt
+    table = methods(func).mt
     # table is a MethodTable object. For some reason, the :kwsorter field is not always
     # defined. An undefined kwsorter seems to imply that there are no methods in the
     # MethodTable with keyword arguments.
     if isdefined(table, :kwsorter)
         # Fetching method keywords stolen from base/replutil.jl:572-576 (commit 3b45cdc9aab0):
-        local kwargs = Base.kwarg_decl(m, typeof(table.kwsorter))
+        kwargs = VERSION < v"1.4.0-DEV.215" ? Base.kwarg_decl(m, typeof(table.kwsorter)) : Base.kwarg_decl(m)
         if isa(kwargs, Vector) && length(kwargs) > 0
             filter!(arg -> !occursin("#", string(arg)), kwargs)
             # Keywords *may* not be sorted correctly. We move the vararg one to the end.
-            local index = findfirst(arg -> endswith(string(arg), "..."), kwargs)
+            index = findfirst(arg -> endswith(string(arg), "..."), kwargs)
             if index != nothing
                 kwargs[index], kwargs[end] = kwargs[end], kwargs[index]
             end

test/tests.jl

@@ -51,13 +51,17 @@ end
         @test isa(m, Method)
         # .. which should have a single keyword argument, :y
         # Base.kwarg_decl returns a Vector{Any} of the keyword arguments.
-        local kwargs = Base.kwarg_decl(m, typeof(mt.kwsorter))
+        local kwargs = VERSION < v"1.4.0-DEV.215" ? Base.kwarg_decl(m, typeof(mt.kwsorter)) : Base.kwarg_decl(m)
         @test isa(kwargs, Vector{Any})
         @test kwargs == [:y]
         # Base.kwarg_decl will return a Tuple{} for some reason when called on a method
         # that does not have any arguments
         m = which(M.j_1, (Any,Any)) # fetch the no-keyword method
-        @test Base.kwarg_decl(m, typeof(methods(M.j_1).mt.kwsorter)) == Tuple{}()
+        if VERSION < v"1.4.0-DEV.215"
+            @test Base.kwarg_decl(m, typeof(methods(M.j_1).mt.kwsorter)) == Tuple{}()
+        else
+            @test Base.kwarg_decl(m) == []
+        end
     end
     @testset "format" begin
         # Setup.