add check to CryptolCode's __call__

cryptol-remote-api/python/cryptol/cryptoltypes.py

@@ -56,7 +56,10 @@ def __to_cryptol__(self, ty : CryptolType) -> Any: ...
 
 class CryptolCode(metaclass=ABCMeta):
     def __call__(self, *others : CryptolJSON) -> CryptolCode:
-        return CryptolApplication(self, *others)
+        if all(hasattr(other, '__to_cryptol__') for other in others):
+            return CryptolApplication(self, *others)
+        else:
+            raise ValueError("Argument to __call__ on CryptolCode is not CryptolJSON")
 
     @abstractmethod
     def __to_cryptol__(self, ty : CryptolType) -> Any: ...
@@ -100,8 +103,7 @@ def __eq__(self, other : Any) -> bool:
         return isinstance(other, CryptolApplication) and self._rator == other._rator and self._rands == other._rands
 
     def __repr__(self) -> str:
-        args = [self._rator, *(arg for arg in self._rands)]
-        return f'CryptolApplication({", ".join(repr(x) for x in args)})'
+        return f'CryptolApplication({", ".join(repr(x) for x in [self._rator, *self._rands])})'
 
 
 class CryptolArrowKind:

cryptol-remote-api/python/tests/cryptol/test_quoting.py

@@ -33,11 +33,15 @@ def test_quoting(self):
         self.assertEqual(cry_f('id {5:#x}'),    cry('id "0x5"'))
         self.assertEqual(cry_f('id {BV(4,5)}'), cry('id 0x5'))
 
+        # Only here to check backwards compatability, the above syntax is preferred
         y = cry('g')(cry_f('{x}'))
         z = cry('h')(cry_f('{y}'))
         self.assertEqual(str(z), str(cry('(h) ((g) (0x01))')))
         self.assertEqual(cry_eval(z), [x,x])
         self.assertEqual(str(cry('id')(cry_f('{BV(size=7, value=1)}'))), str(cry('(id) (1 : [7])')))
+        # This is why this syntax is not preferred
+        with self.assertRaises(ValueError):
+            cry('g')(x) # x is not CryptolJSON
 
 
 if __name__ == "__main__":