Make scopes more memory efficient

auto_editor/lang/palet.py

@@ -765,8 +765,7 @@ def __call__(self, *args: Any) -> Any:
             largs = list(args)
             args = tuple([largs[len(self.parms) - 1 :]])
 
-        inner_env = self.env.copy()
-        inner_env.update(dict(zip(self.parms, args)))
+        inner_env = Env(dict(zip(self.parms, args)), self.env)
 
         for item in self.body[0:-1]:
             my_eval(inner_env, item)
@@ -1158,7 +1157,7 @@ def my_eval(env: Env, node: object) -> Any:
 
 
 # fmt: off
-env = Env()
+env = Env({})
 env.update({
     # constants
     "true": True,

auto_editor/lib/data_structs.py

@@ -8,33 +8,43 @@
 
 
 class Env:
-    __slots__ = "data"
+    __slots__ = ("data", "outer")
 
-    def __init__(self) -> None:
-        self.data: dict[str, Any] = {}
+    def __init__(self, data: dict[str, Any], outer: Env | None = None) -> None:
+        self.data = data
+        self.outer = outer
 
     def __getitem__(self, key: str) -> Any:
-        return self.data[key]
+        if key in self.data:
+            return self.data[key]
+        if self.outer is not None:
+            return self.outer[key]
 
     def __setitem__(self, key: str, val: Any) -> None:
         self.data[key] = val
 
     def __delitem__(self, key: str) -> None:
-        del self.data[key]
-
-    def __contains__(self, item: Any) -> bool:
-        return item in self.data
+        if key in self.data:
+            del self.data[key]
+        elif self.outer is not None:
+            del self.outer[key]
+
+    def __contains__(self, key: str) -> bool:
+        if key in self.data:
+            return True
+        if self.outer is not None:
+            return key in self.outer
+        return False
 
     def update(self, my_dict: dict[str, Any]) -> None:
         self.data.update(my_dict)
 
     def get(self, key: str) -> Any:
-        return self.data.get(key)
-
-    def copy(self) -> Env:
-        new_env = Env()
-        new_env.update(self.data.copy())
-        return new_env
+        if key in self.data:
+            return self.data[key]
+        if self.outer is not None:
+            return self.outer.get(key)
+        return None
 
 
 class Sym:

auto_editor/utils/cmdkw.py

@@ -121,11 +121,7 @@ def parse_with_palet(
 
     def go(text: str, c: Any) -> Any:
         try:
-            if isinstance(_env, Env):
-                env = _env
-            else:
-                env = Env()
-                env.update(_env)
+            env = _env if isinstance(_env, Env) else Env(_env)
             results = interpret(env, Parser(Lexer(build.name, text)))
         except MyError as e:
             raise ParserError(e)