add yet another metatable implementation..

Author: CapsAdmin

nattlua/definitions/lua/globals.nlua

@@ -503,7 +503,34 @@ analyzer function setmetatable(tbl: Table, meta: Table | nil)
 	end
 
 	if meta.Type == "table" then
-		if meta.Self then
+		if meta.NewMetaTable and not meta.Self then
+			-- @NewMetaTable mode: build an inferred Self from tbl's fields
+			-- This is informational (no contract enforcement)
+			local inferred_self = types.Table()
+			for _, kv in ipairs(tbl:GetData()) do
+				local key = kv.key
+				local val = kv.val
+				-- Widen literal values to their base types for the inferred self
+				if val:IsLiteral() and val.Type ~= "function" and val.Type ~= "table" and val.Widen then
+					val = val:Widen()
+				end
+				inferred_self:Set(key, val)
+			end
+			inferred_self:SetMetaTable(meta)
+			meta.Self = inferred_self
+		elseif meta.NewMetaTable and meta.Self then
+			-- Subsequent setmetatable calls: merge additional fields
+			for _, kv in ipairs(tbl:GetData()) do
+				local key = kv.key
+				local val = kv.val
+				if val:IsLiteral() and val.Type ~= "function" and val.Type ~= "table" and val.Widen then
+					val = val:Widen()
+				end
+				if not meta.Self:HasKey(key) then
+					meta.Self:Set(key, val)
+				end
+			end
+		elseif meta.Self then
 			analyzer:ErrorIfFalse(tbl:FollowsContract(meta.Self))
 			tbl:CopyLiteralness2(meta.Self)
 			tbl:SetContract(meta.Self)

nattlua/types/table.lua

@@ -38,6 +38,7 @@ META:GetSet("BaseTable", nil--[[# as TTable | false]])
 META:GetSet("ReferenceId", nil--[[# as string | false]])
 META:GetSet("Self", nil--[[# as false | TTable]])
 META:GetSet("Self2", nil--[[# as false | TTable]])
+META:GetSet("NewMetaTable", false--[[# as boolean]])
 META:GetSet("Contracts", nil--[[# as List<|TTable|>]])
 META:GetSet("CreationScope", nil--[[# as any]])
 META:GetSet("AnalyzerEnvironment", false--[[# as false | "runtime" | "typesystem"]])
@@ -85,6 +86,14 @@ function META:SetSelf(tbl--[[#: TTable]])
 	self.Self = tbl
 end
 
+function META:SetNewMetaTable(val)
+	if val and val.Type == "symbol" and val:IsTrue() then
+		self.NewMetaTable = true
+	else
+		self.NewMetaTable = false
+	end
+end
+
 function META.Equal(
 	a--[[#: TTable]],
 	b--[[#: TBaseType]],
@@ -1099,6 +1108,7 @@ function META:Copy(map--[[#: Map<|any, any|> | nil]], copy_tables)
 	end
 
 	copy.Self2 = self.Self2
+	copy.NewMetaTable = self.NewMetaTable
 	copy.MetaTable = self.MetaTable --copy_val(self.MetaTable, map, copy_tables)
 	copy.Contract = self:GetContract() --copy_val(self.Contract, map, copy_tables)
 	copy:SetAnalyzerEnvironment(self:GetAnalyzerEnvironment())
@@ -1465,6 +1475,7 @@ function META.New()
 			Name = false,
 			Self = false,
 			Self2 = false,
+			NewMetaTable = false,
 			literal_data_cache = {},
 			Contracts = {},
 			TypeOverride = false,