add docstring, and emit deprecation warnings

IPython/core/inputsplitter.py

@@ -16,6 +16,11 b' and stores the results.'
 For more details, see the class docstrings below.
 """
 
+from warnings import warn
+
+warn('IPython.core.inputsplitter is deprecated since IPython 7 in favor of `IPython.core.inputtransformer2`',
+     DeprecationWarning)
+
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 import ast

IPython/core/interactiveshell.py

@@ -349,10 +349,15 b' class InteractiveShell(SingletonConfigurable):'
 
     @property
     def input_splitter(self):
-        """Make this available for compatibility
+        """Make this available for backward compatibility (pre-7.0 release) with existing code.
 
-        ipykernel currently uses shell.input_splitter.check_complete
+        For example, ipykernel ipykernel currently uses
+        `shell.input_splitter.check_complete`
         """
+        from warnings import warn
+        warn("`input_splitter` is deprecated since IPython 7.0, prefer `input_transformer_manager`.",
+             DeprecationWarning, stacklevel=2
+        )
         return self.input_transformer_manager
 
     logstart = Bool(False, help=

IPython/core/tests/test_inputtransformer2.py

@@ -1,3 +1,9 b''
+"""Tests for the token-based transformers in IPython.core.inputtransformer2
+
+Line-based transformers are the simpler ones; token-based transformers are
+more complex.
+"""
+
 import nose.tools as nt
 
 from IPython.core import inputtransformer2 as ipt2