feat: Added custom interface forwarding (#11)

fix: Fix map_func argument forwarding

Author: curtd

Project.toml

@@ -5,7 +5,9 @@ version = "1.4.2"
 
 [deps]
 MLStyle = "d8e11817-5142-5d16-987a-aa16d5891078"
+MacroUtilities = "274a0f0b-05f4-4024-87ff-de4a5b524b4f"
 
 [compat]
 MLStyle = "0.4"
+MacroUtilities = "1.6.1"
 julia = "1.6"

src/ForwardMethods.jl

@@ -1,5 +1,5 @@
 module ForwardMethods
-    using MLStyle 
+    using MacroUtilities, MLStyle
 
     export @forward_methods, @forward_interface, @define_interface
 

src/define_interface.jl

@@ -1,5 +1,3 @@
-define_interface_method(x) = nothing
-
 """
     properties_interface(T; delegated_fields, [is_mutable=false])
 
@@ -12,7 +10,6 @@ If `T` is a mutable type, also defines `Base.setproperty!(x::T, name::Symbol, va
 # Arguments 
 `delegated_fields` can be either a `Symbol`, or a `vect` or `tuple` `Expr` of `Symbol`s, corresponding to fieldnames of `T`
 
-
 """
 function properties_interface(T; delegated_fields, kwargs...)
     delegated_fields_sym = parse_vect_of_symbols(delegated_fields; kwarg_name=:delegated_fields)
@@ -108,19 +105,26 @@ function equality_interface(T; omit::AbstractVector{Symbol}=Symbol[], equality_o
     return wrap_define_interface(T, :equality, equality_expr)
 end
 
-const define_interfaces_available = (:properties, :equality, :setfields, :getfields)
+const default_define_interfaces = (:properties, :equality, :setfields, :getfields)
 
-for f in define_interfaces_available
+for f in default_define_interfaces
     @eval define_interface_method(::Val{$(QuoteNode(f))}) = $(Symbol(string(f)*"_interface"))
 end
 
+@static if VERSION < v"1.10"
+    @method_def_constant define_interface_method(::Val{::Symbol}) define_interfaces_available
+else
+    define_interfaces_available() = default_define_interfaces
+end
+
 function define_interface_expr(T, kwargs::Dict{Symbol,Any}=Dict{Symbol,Any}())
     interfaces = interface_kwarg!(kwargs)
     omit = omit_kwarg!(kwargs)
     output = Expr(:block)
+    interfaces_available = define_interfaces_available()
     for interface in interfaces
+        interface in interfaces_available || error("No interface found with name $interface -- must be one of `$interfaces_available`")
         f = define_interface_method(Val(interface))
-        isnothing(f) && error("No interface found with name $interface -- must be one of `$define_interfaces_available`")
         push!(output.args, f(T; omit, kwargs...))
     end
     return output
@@ -132,7 +136,7 @@ end
 Defines the `interface` for objects of type `T`
 
 # Arguments 
-`name` must be one of $(define_interfaces_available), with `name` value `f` corresponding to the interface definition function `\$f_interface` (e.g., `array` => `array_interface`).
+`name` must be one of $(default_define_interfaces), with `name` value `f` corresponding to the interface definition function `\$f_interface` (e.g., `array` => `array_interface`).
 
 The `key=value` pairs will be forwarded to the corresponding interface definition method. In particular, specifying `omit=func1` or `omit=[func1,func2, ..., funcn]` will omit `func1`, ..., `funcn` from being forwarded by this macro.
 

src/forward_interface.jl

@@ -1,4 +1,5 @@
-forward_interface_method(x) = nothing
+function forward_interface_method end 
+
 interface_field_name_required(x) = false 
 interface_at_macroexpand_time(x) = true
 base_forward_expr(f, args...) = Expr(:call, f, args...)
@@ -246,7 +247,7 @@ end
 
 Given `x::T`, forwards the method `\$field(x::T)` to `getfield(x, \$field)`, for each `field in fieldnames(T)`
 """
-function getfields_interface(T; omit::AbstractVector{Symbol}=Symbol[])
+function getfields_interface(T; field::Union{Nothing,Symbol}=nothing, omit::AbstractVector{Symbol}=Symbol[])
     return wrap_define_interface(T, :getfields, Base.remove_linenums!(quote 
         local omit_fields = $(Expr(:tuple, QuoteNode.(omit)...))
         local fields = fieldnames($T)
@@ -269,7 +270,7 @@ interface_at_macroexpand_time(::typeof(getfields_interface)) = false
 
 Given `x::T`, forwards the method `\$field!(x::T, value)` to `setfield!(x, \$field, value)`, for each `field in fieldnames(T)`
 """
-function setfields_interface(T; omit::AbstractVector{Symbol}=Symbol[])
+function setfields_interface(T; field::Union{Nothing,Symbol}=nothing, omit::AbstractVector{Symbol}=Symbol[])
     return wrap_define_interface(T, :setfields, Base.remove_linenums!(quote 
         local omit_fields = $(Expr(:tuple, QuoteNode.(omit)...))
         local fields = fieldnames($T)
@@ -287,13 +288,18 @@ end
 
 interface_at_macroexpand_time(::typeof(setfields_interface)) = false
 
+const default_forward_interfaces = (:iteration, :indexing, :array, :vector, :dict, :lockable, :getfields, :setfields) 
 
-const forward_interfaces_available = (:iteration, :indexing, :array, :vector, :dict, :lockable, :getfields, :setfields)
-
-for f in forward_interfaces_available 
+for f in default_forward_interfaces
     @eval forward_interface_method(::Val{$(QuoteNode(f))}) = $(Symbol(string(f)*"_interface"))
 end
 
+@static if VERSION < v"1.10"
+    @method_def_constant forward_interface_method(::Val{::Symbol}) forward_interfaces_available
+else
+    forward_interfaces_available() = default_forward_interfaces
+end
+
 function forward_interface_expr(T, kwargs::Dict{Symbol,Any}=Dict{Symbol,Any}(); _sourceinfo=nothing)
     interfaces = interface_kwarg!(kwargs)
     omit = omit_kwarg!(kwargs)
@@ -312,9 +318,13 @@ function forward_interface_expr(T, kwargs::Dict{Symbol,Any}=Dict{Symbol,Any}();
     end
 
     _output = Expr(:block)
+
+    available_interfaces = forward_interfaces_available()
+
     for interface in interfaces
+        interface in available_interfaces || error("No interface found with name $interface -- must be one of `$available_interfaces`")
+
         f = forward_interface_method(Val(interface))
-        isnothing(f) && error("No interface found with name $interface -- must be one of `$forward_interfaces_available`")
 
         if interface_at_macroexpand_time(f)
             isnothing(field_funcs) && error("Expected `field` from keyword arguments for interface `$interface`")
@@ -341,7 +351,7 @@ end
 Forwards the methods defined for `interface` to objects of type `T`
 
 # Arguments 
-`name` must be one of $(forward_interfaces_available), with `name` value `f` corresponding to the interface definition function `\$f_interface` (e.g., `array` => `array_interface`).
+`name` must be one of $(default_forward_interfaces), with `name` value `f` corresponding to the interface definition function `\$f_interface` (e.g., `array` => `array_interface`).
 
 If `name` is either `getfields` or `setfields`, then the `field` keyword argument is ignored 
 

src/forward_methods.jl

@@ -228,7 +228,7 @@ function forward_methods_expr(Type, field_expr, args...; _sourceinfo=nothing)
 
     output = Expr(:block)
     for arg in method_exprs
-        push!(output.args, forward_method_signature(Type, field_funcs, arg; _sourceinfo))
+        push!(output.args, forward_method_signature(Type, field_funcs, map_func,  arg; _sourceinfo))
     end
     return output
 end

test/TestForwardMethods.jl

@@ -13,10 +13,26 @@ module TestForwardMethods
         return output |> esc
     end
 
+    custom_func_to_forward(t) = t[1]
+
+    function custom_interface(T; omit::AbstractVector{Symbol}=Symbol[])
+        return [:custom_func_to_forward]
+    end
+    @static if VERSION < v"1.10"
+        @Test !(:custom in ForwardMethods.forward_interfaces_available())
+    end
+    ForwardMethods.forward_interface_method(::Val{:custom}) = custom_interface
+    @static if VERSION < v"1.10"
+        @Test :custom in ForwardMethods.forward_interfaces_available()
+    end
+
     struct A
         v::Vector{Int}
     end
     @forward_methods A field=v Base.length(x::A) Base.getindex(_, k) Base.eltype(::Type{A})
+    @static if VERSION < v"1.10"
+        @forward_interface A field=v interface=custom
+    end
 
     test_func(v::Vector) = v[1]
 
@@ -299,6 +315,9 @@ module TestForwardMethods
             @test matches
         end
 
+        @static if VERSION < v"1.10"
+            @Test custom_func_to_forward(A([0])) == 0
+        end
         @Test length(A([0])) == 1
         @Test A([0])[1] == 0
         @Test eltype(A) == Int