support functors in @Accessor

src/sugar.jl

@@ -417,19 +417,23 @@ macro accessor(ex)
     arg = only(def[:args])
     argname = splitarg(arg)[1]
     body_optic = MacroTools.replace(def[:body], argname, :_)
-    ftype = :(
-        if $fname isa Function
-            typeof($fname)
-        elseif $fname isa Type
-            Type{$fname}
-        else
-            # is it possible at all?
-            error("Unsupported accessor $(fname)::$(typeof($fname))")
-        end
-    )
+    farg = if @capture fname name_::T__
+        fname
+    else
+        ftype = :(
+            ::if $fname isa Function
+                typeof($fname)
+            elseif $fname isa Type
+                Type{$fname}
+            else
+                # is it possible at all?
+                error("Unsupported accessor $(fname)::$(typeof($fname))")
+            end
+        )
+    end
     quote
         Base.@__doc__ $ex
-        $Accessors.set($arg, ::$ftype, v) = $set($argname, $Accessors.@optic($body_optic), v)
+        $Accessors.set($arg, $farg, v) = $set($argname, $Accessors.@optic($body_optic), v)
     end |> esc
 end
 

test/test_core.jl

@@ -574,6 +574,7 @@ end
 @accessor Base.:(+)(s::MyStruct) = 5 - s.x.a
 @accessor Base.Int(s::MyStruct) = s.x[1]
 @accessor Base.Float64(s::MyStruct) = s.x[2]
+@accessor (t::MyStruct)(s::MyStruct) = s.x + t.x
 
 @testset "@accessor" begin
     s = MyStruct((a=123,))
@@ -586,6 +587,8 @@ end
     s = MyStruct((1, 2.0))
     Accessors.test_getset_laws(Int, s, 1, 2)
     Accessors.test_getset_laws(Float64, s, 1., 2.)
+
+    Accessors.test_getset_laws(MyStruct(2), MyStruct(1), 1, 2)
 end
 
 end