lib.base: Add module

Add lib.base to provide basic definitions.

For now, move the definiions of Result, Input and InputMode from
ExecContext into lib.base. Having to import them from the ExecContect
module is too heavy-handed for those simple types.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/base.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import annotations
+
+from enum import Enum, auto
+from typing import NamedTuple, TypeAlias, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from typing import Type
+
+class InputMode(Enum):
+    Interactive = auto()
+    NonInteractive = auto()
+    OptInteractive = auto()
+    Auto = auto()
+
+Input: TypeAlias = InputMode | bytes | str
+
+class Result(NamedTuple):
+
+    stdout: str|None
+    stderr: str|None
+    status: int|None
+
+    def decode(self, encoding='UTF-8', errors='replace') -> Result:
+        return Result(
+            self.stdout.decode(encoding, errors=errors) if self.stdout is not None else None,
+            self.stderr.decode(encoding, errors=errors) if self.stderr is not None else None,
+            self.status
+        )