Enforce type annotations at function definition time

- Added @strict_types decorator that validates all parameters have type hints
- Functions without type annotations now raise TypeError at definition time
- All functions in the module decorated with @strict_types
- def my_func(var1, var2): raises TypeError (no annotations)
- def my_func(var1: str, var2: int): is accepted (has annotations)

Co-authored-by: johndoe6345789 <224850594+johndoe6345789@users.noreply.github.com>

Programs/_freeze_module.py

@@ -10,15 +10,42 @@ reference `hashtable`.
 
 This version enforces strict type checking with runtime validation.
 An exception is thrown if something is not typed correctly.
+All function parameters must have type annotations.
 """
 
+import inspect
 import marshal
 import sys
-from typing import TextIO
+from typing import TextIO, get_type_hints
 
 header: str = "/* Auto-generated by Programs/_freeze_module.py */"
 
 
+def strict_types(func):
+    """Decorator that enforces type annotations on all parameters.
+    
+    Raises:
+        TypeError: If any parameter lacks a type annotation
+    """
+    sig = inspect.signature(func)
+    
+    # Check that all parameters have annotations
+    for param_name, param in sig.parameters.items():
+        if param.annotation == inspect.Parameter.empty:
+            raise TypeError(
+                f"Function '{func.__name__}' parameter '{param_name}' "
+                f"must have a type annotation"
+            )
+    
+    # Check that return type is annotated
+    if sig.return_annotation == inspect.Signature.empty:
+        raise TypeError(
+            f"Function '{func.__name__}' must have a return type annotation"
+        )
+    
+    return func
+
+
 def _check_type(value, expected_type, param_name: str) -> None:
     """Enforce strict type checking at runtime.
     
@@ -39,6 +66,7 @@ def _check_type(value, expected_type, param_name: str) -> None:
         )
 
 
+@strict_types
 def read_text(inpath: str) -> bytes:
     """Read text from a file and return as bytes.
     
@@ -59,6 +87,7 @@ def read_text(inpath: str) -> bytes:
     return result
 
 
+@strict_types
 def compile_and_marshal(name: str, text: bytes) -> bytes:
     """Compile Python source code and marshal it.
     
@@ -83,6 +112,7 @@ def compile_and_marshal(name: str, text: bytes) -> bytes:
     return result
 
 
+@strict_types
 def get_varname(name: str, prefix: str) -> str:
     """Generate a C variable name from a module name.
     
@@ -103,6 +133,7 @@ def get_varname(name: str, prefix: str) -> str:
     return result
 
 
+@strict_types
 def write_code(outfile: TextIO, marshalled: bytes, varname: str) -> None:
     """Write marshalled code as C array to output file.
     
@@ -134,6 +165,7 @@ def write_code(outfile: TextIO, marshalled: bytes, varname: str) -> None:
     outfile.write("};\n")
 
 
+@strict_types
 def write_frozen(outpath: str, inpath: str, name: str, marshalled: bytes) -> None:
     """Write frozen module to output file.
     
@@ -158,6 +190,7 @@ def write_frozen(outpath: str, inpath: str, name: str, marshalled: bytes) -> Non
         write_code(outfile, marshalled, arrayname)
 
 
+@strict_types
 def main() -> None:
     """Main entry point for the freeze_module program.