To fix the memory leak, move the inline condition filter out of functions.

Author: vicalloy

src/prompt_toolkit/key_binding/bindings/basic.py

@@ -29,6 +29,16 @@ def if_no_repeat(event: E) -> bool:
     return not event.is_repeat
 
 
+@Condition
+def has_text_before_cursor() -> bool:
+    return bool(get_app().current_buffer.text)
+
+
+@Condition
+def in_quoted_insert() -> bool:
+    return get_app().quoted_insert
+
+
 def load_basic_bindings() -> KeyBindings:
     key_bindings = KeyBindings()
     insert_mode = vi_insert_mode | emacs_insert_mode
@@ -171,10 +181,6 @@ def _ignore(event: E) -> None:
 
     # CTRL keys.
 
-    @Condition
-    def has_text_before_cursor() -> bool:
-        return bool(get_app().current_buffer.text)
-
     handle("c-d", filter=has_text_before_cursor & insert_mode)(
         get_by_name("delete-char")
     )
@@ -240,10 +246,6 @@ def _paste(event: E) -> None:
 
         event.current_buffer.insert_text(data)
 
-    @Condition
-    def in_quoted_insert() -> bool:
-        return get_app().quoted_insert
-
     @handle(Keys.Any, filter=in_quoted_insert, eager=True)
     def _insert_text(event: E) -> None:
         """

src/prompt_toolkit/key_binding/bindings/emacs.py

@@ -33,6 +33,11 @@
 E = KeyPressEvent
 
 
+@Condition
+def is_returnable() -> bool:
+    return get_app().current_buffer.is_returnable
+
+
 def load_emacs_bindings() -> KeyBindingsBase:
     """
     Some e-macs extensions.
@@ -142,10 +147,6 @@ def _dash(event: E) -> None:
         """
         event.app.key_processor.arg = "-"
 
-    @Condition
-    def is_returnable() -> bool:
-        return get_app().current_buffer.is_returnable
-
     # Meta + Enter: always accept input.
     handle("escape", "enter", filter=insert_mode & is_returnable)(
         get_by_name("accept-line")

src/prompt_toolkit/key_binding/bindings/vi.py

@@ -371,6 +371,35 @@ def _operator_in_selection(event: E) -> None:
     return operator_decorator
 
 
+@Condition
+def is_returnable() -> bool:
+    return get_app().current_buffer.is_returnable
+
+
+@Condition
+def in_block_selection() -> bool:
+    buff = get_app().current_buffer
+    return bool(
+        buff.selection_state and buff.selection_state.type == SelectionType.BLOCK
+    )
+
+
+@Condition
+def digraph_symbol_1_given() -> bool:
+    return get_app().vi_state.digraph_symbol1 is not None
+
+
+@Condition
+def search_buffer_is_empty() -> bool:
+    "Returns True when the search buffer is empty."
+    return get_app().current_buffer.text == ""
+
+
+@Condition
+def tilde_operator() -> bool:
+    return get_app().vi_state.tilde_operator
+
+
 def load_vi_bindings() -> KeyBindingsBase:
     """
     Vi extensions.
@@ -410,7 +439,7 @@ def load_vi_bindings() -> KeyBindingsBase:
         (("g", "~"), Always(), lambda string: string.swapcase()),
         (
             ("~",),
-            Condition(lambda: get_app().vi_state.tilde_operator),
+            tilde_operator,
             lambda string: string.swapcase(),
         ),
     ]
@@ -528,10 +557,6 @@ def _cancel_completion(event: E) -> None:
         """
         event.current_buffer.cancel_completion()
 
-    @Condition
-    def is_returnable() -> bool:
-        return get_app().current_buffer.is_returnable
-
     # In navigation mode, pressing enter will always return the input.
     handle("enter", filter=vi_navigation_mode & is_returnable)(
         get_by_name("accept-line")
@@ -681,13 +706,6 @@ def _I(event: E) -> None:
             )
         )
 
-    @Condition
-    def in_block_selection() -> bool:
-        buff = get_app().current_buffer
-        return bool(
-            buff.selection_state and buff.selection_state.type == SelectionType.BLOCK
-        )
-
     @handle("I", filter=in_block_selection & ~is_read_only)
     def insert_in_block_selection(event: E, after: bool = False) -> None:
         """
@@ -2071,10 +2089,6 @@ def _digraph(event: E) -> None:
         """
         event.app.vi_state.waiting_for_digraph = True
 
-    @Condition
-    def digraph_symbol_1_given() -> bool:
-        return get_app().vi_state.digraph_symbol1 is not None
-
     @handle(Keys.Any, filter=vi_digraph_mode & ~digraph_symbol_1_given)
     def _digraph1(event: E) -> None:
         """
@@ -2180,11 +2194,6 @@ def load_vi_search_bindings() -> KeyBindingsBase:
     handle = key_bindings.add
     from . import search
 
-    @Condition
-    def search_buffer_is_empty() -> bool:
-        "Returns True when the search buffer is empty."
-        return get_app().current_buffer.text == ""
-
     # Vi-style forward search.
     handle(
         "/",