Allow user-defined types as variadic argument

src/engines/v8/generate.zig

@@ -291,7 +291,7 @@ fn getArgs(
         comptime var arg_real: refl.Type = undefined;
 
         comptime {
-            if (try refl.Type.variadic(arg.underT())) |arg_v| {
+            if (try refl.Type.variadic(arg.underT(), all_T)) |arg_v| {
                 arg_real = arg_v;
             } else {
                 arg_real = arg;
@@ -389,7 +389,7 @@ fn freeArgs(alloc: std.mem.Allocator, comptime func: refl.Func, obj: anytype) !v
         }
 
         // free varidadic slices
-        if (try refl.Type.variadic(arg_T.underT()) != null) {
+        if (try refl.Type.variadic(arg_T.underT(), null) != null) {
             const val = @field(obj, arg_T.name.?).?;
             // NOTE: variadic are optional by design
             alloc.free(@field(val, "slice"));

src/reflect.zig

@@ -222,15 +222,19 @@ pub const Type = struct {
 
     // find if T is a VariadicType
     // and returns it as a reflect.Type
-    pub fn variadic(comptime T: type) !?Type {
+    pub fn variadic(comptime T: type, comptime structs: ?[]Struct) !?Type {
         std.debug.assert(@inComptime());
 
-        const tt = Type._variadic(T) orelse return null;
+        const TT = Type._variadic(T) orelse return null;
 
         // avoid infinite calls
-        if (Type._is_variadic(tt)) return error.TypeVariadicNested;
+        if (Type._is_variadic(TT)) return error.TypeVariadicNested;
 
-        return try Type.reflect(tt, null);
+        var tt = try Type.reflect(TT, null);
+        if (structs) |all| {
+            try tt.lookup(all);
+        }
+        return tt;
     }
 
     // check that user-defined types have been provided as an API
@@ -257,7 +261,7 @@ pub const Type = struct {
         }
 
         // if variadic, lookup the concrete type
-        var variadic_type = try Type.variadic(self.underT());
+        var variadic_type = try Type.variadic(self.underT(), null);
         if (variadic_type) |*tt| {
             return tt.lookup(structs);
         }
@@ -765,6 +769,7 @@ pub const Struct = struct {
     }
 
     fn lookupTypes(comptime self: *Struct, comptime structs: []Struct) Error!void {
+        try self.value.lookup(structs);
         if (self.has_constructor) {
             try self.constructor.lookupTypes(structs);
         }

src/tests/types_complex_test.zig

@@ -54,6 +54,17 @@ const MyVariadic = struct {
         return true;
     }
 
+    const VariadicList = Variadic(MyList);
+
+    pub fn _myListLen(_: MyVariadic, variadic: ?VariadicList) u8 {
+        return @as(u8, @intCast(variadic.?.slice.len));
+    }
+
+    pub fn _myListFirst(_: MyVariadic, variadic: ?VariadicList) ?u8 {
+        if (variadic.?.slice.len == 0) return null;
+        return variadic.?.slice[0]._first();
+    }
+
     pub fn deinit(_: *MyVariadic, _: std.mem.Allocator) void {}
 };
 
@@ -189,6 +200,8 @@ pub fn exec(
         .{ .src = "myVariadic.first('a_str', true, false, true, false)", .ex = "true" },
         .{ .src = "myVariadic.last(true, false)", .ex = "false" },
         .{ .src = "myVariadic.empty()", .ex = "true" },
+        .{ .src = "myVariadic.myListLen(myList)", .ex = "1" },
+        .{ .src = "myVariadic.myListFirst(myList)", .ex = "1" },
     };
     try tests.checkCases(js_env, &variadic);