refactor: use TypedDict for exec program output (#1322)

Signed-off-by: Louis Mandel <[email protected]>

Author: mandel

src/pdl/pdl.py

@@ -12,6 +12,7 @@
 from . import pdl_interpreter
 from ._version import version
 from .pdl_ast import (
+    BlockType,
     PdlBlock,
     PdlLocationType,
     Program,
@@ -58,6 +59,13 @@ class InterpreterConfig(TypedDict, total=False):
     """Event loop to schedule LLM calls."""
 
 
+class Result(TypedDict):
+    result: Any
+    scope: dict[str, Any]
+    trace: BlockType
+    replay: dict[str, Any]
+
+
 def exec_program(
     prog: Program,
     config: Optional[InterpreterConfig] = None,
@@ -92,13 +100,13 @@ def exec_program(
         case "result":
             return result
         case "all":
-            scope = future_scope.result()
-            return {
+            result_all: Result = {
                 "result": result,
-                "scope": scope,
+                "scope": future_scope.result(),
                 "trace": trace,
                 "replay": state.replay,
             }
+            return result_all
         case _:
             assert False, 'The `output` variable should be "result" or "all"'