Implement an ad-hoc hot reload

Author: tkf

src/replhelper/__init__.py

@@ -1 +1 @@
-from .core import customized_ipython, ipython_options
+from .core import customized_ipython, ipython_options, revise

src/replhelper/core.py

@@ -1,8 +1,21 @@
+# TODO: replace object.__XXX__(self, ...) with super().__XXX__(...)
+# once Python 2 support is removed.
+
 from __future__ import print_function
 
 import warnings
 import sys
 
+try:
+    from importlib import reload
+except ImportError:
+    try:
+        from imp import reload
+    except ImportError:
+        pass  # Python 2?
+
+_Main = None
+
 
 def jl_name(name):
     if name.endswith('_b'):
@@ -32,13 +45,15 @@ def __init__(self, julia):
 
     def __setattr__(self, name, value):
         if name.startswith('_'):
-            super(JuliaNameSpace, self).__setattr__(name, value)
+            object.__setattr__(self, name, value)
+            # super().__setattr__(name, value)
         else:
             self.__julia.set_var(name, value)
 
     def __getattr__(self, name):
         if name.startswith('_'):
-            return super(JuliaNameSpace, self).__getattr__(name)
+            return object.__getattr__(self, name)
+            # return super().__getattr__(name)
         else:
             return self.__julia.eval(jl_name(name))
 
@@ -51,7 +66,7 @@ def __dir__(self):
         if sys.version_info.major == 2:
             names = set()
         else:
-            names = set(super(JuliaNameSpace, self).__dir__())
+            names = set(super().__dir__())
         names.update(self.__all__)
         return list(names)
     # Override __dir__ method so that completing member names work
@@ -133,9 +148,10 @@ def wrapped(*args, **kwargs):
 
 
 def ipython_options(**kwargs):
+    global _Main
     from traitlets.config import Config
 
-    Main = JuliaNameSpace(JuliaAPI(**kwargs))
+    _Main = Main = JuliaNameSpace(JuliaAPI(**kwargs))
     user_ns = dict(
         Main=Main,
     )
@@ -178,3 +194,16 @@ def customized_ipython(**kwargs):
         warnings.warn(segfault_warning.format(**vars()))
         segfault_warned = True
     IPython.start_ipython(**ipython_options(**kwargs))
+
+
+def revise():
+    """Ad-hoc hot reload."""
+    import replhelper
+    reload(replhelper.core)
+
+    if _Main is not None:
+        _Main.__class__ = replhelper.core.JuliaNameSpace
+        _Main._JuliaNameSpace__julia.__class__ = replhelper.core.JuliaAPI
+        replhelper.core._Main = _Main
+
+    reload(replhelper)