1 files changed, 36 insertions, 0 deletions
diff --git a/ptpython/filters.py b/ptpython/filters.py
new file mode 100644
index 0000000..1adac13
--- /dev/null
+++ b/ptpython/filters.py
@@ -0,0 +1,36 @@
+from typing import TYPE_CHECKING
+
+from prompt_toolkit.filters import Filter
+
+if TYPE_CHECKING:
+    from .python_input import PythonInput
+
+__all__ = ["HasSignature", "ShowSidebar", "ShowSignature", "ShowDocstring"]
+
+
+class PythonInputFilter(Filter):
+    def __init__(self, python_input: "PythonInput") -> None:
+        self.python_input = python_input
+
+    def __call__(self) -> bool:
+        raise NotImplementedError
+
+
+class HasSignature(PythonInputFilter):
+    def __call__(self) -> bool:
+        return bool(self.python_input.signatures)
+
+
+class ShowSidebar(PythonInputFilter):
+    def __call__(self) -> bool:
+        return self.python_input.show_sidebar
+
+
+class ShowSignature(PythonInputFilter):
+    def __call__(self) -> bool:
+        return self.python_input.show_signature
+
+
+class ShowDocstring(PythonInputFilter):
+    def __call__(self) -> bool:
+        return self.python_input.show_docstring