Add Struct:get_strict

anselme/ast/Environment.lua

@@ -157,16 +157,14 @@ local Environment = ast.abstract.Runtime {
 	-- returns nil if undefined
 	_lookup = function(self, state, identifier)
 		local _cache = self._lookup_cache
-		local var
-		if not _cache:has(state, identifier) then
+		local var = _cache:get_strict(state, identifier)
+		if not var then
 			if self.variables:has(state, identifier) then
 				var = self.variables:get(state, identifier)
 			elseif self.parent then
 				var = self.parent:_lookup(state, identifier)
 			end
 			if var then _cache:set(state, identifier, var) end
-		else
-			var = _cache:get(state, identifier)
 		end
 		if var and not var:undefined(state) then
 			return var
@@ -177,8 +175,8 @@ local Environment = ast.abstract.Runtime {
 	_lookup_in_current = function(self, state, symbol)
 		local identifier = symbol:to_identifier()
 		local _cache = self._lookup_cache_current
-		local var
-		if not _cache:has(state, identifier) then
+		local var = _cache:get_strict(state, identifier)
+		if not var then
 			local name = symbol.string
 			if self.variables:has(state, identifier) then
 				var = self.variables:get(state, identifier)
@@ -188,8 +186,6 @@ local Environment = ast.abstract.Runtime {
 				end
 			end
 			if var then _cache:set(state, identifier, var) end
-		else
-			var = _cache:get(state, identifier)
 		end
 		if var and not var:undefined(state) then
 			return var

anselme/ast/Struct.lua

@@ -109,11 +109,17 @@ Struct = ast.abstract.Runtime {
 	end,
 
 	get = function(self, key)
+		local v = self:get_strict(key)
+		if v ~= nil then
+			return v
+		else
+			return Nil:new()
+		end
+	end,
+	get_strict = function(self, key)
 		local hash = key:hash()
 		if self.table[hash] then
 			return self.table[hash][2]
-		else
-			return Nil:new()
 		end
 	end,
 	has = function(self, key)

anselme/ast/Table.lua

@@ -41,6 +41,10 @@ Table = ast.abstract.Runtime {
 		return self.branched:get(state)
 	end,
 
+	get_strict = function(self, state, key)
+		local s = self.branched:get(state)
+		return s:get_strict(key)
+	end,
 	get = function(self, state, key)
 		local s = self.branched:get(state)
 		return s:get(key)