Patch #1601678: move intern() to sys.intern().

birkenfeld · birkenfeld · commit 66a796e5ab8d · 2006-12-19T20:50:34.000Z
diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex
@@ -1262,17 +1262,3 @@ \section{Non-essential Built-in Functions \label{non-essential-built-in-funcs}}
   argument).
 \end{funcdesc}
 
-\begin{funcdesc}{intern}{string}
-  Enter \var{string} in the table of ``interned'' strings and return
-  the interned string -- which is \var{string} itself or a copy.
-  Interning strings is useful to gain a little performance on
-  dictionary lookup -- if the keys in a dictionary are interned, and
-  the lookup key is interned, the key comparisons (after hashing) can
-  be done by a pointer compare instead of a string compare.  Normally,
-  the names used in Python programs are automatically interned, and
-  the dictionaries used to hold module, class or instance attributes
-  have interned keys.  \versionchanged[Interned strings are not
-  immortal (like they used to be in Python 2.2 and before);
-  you must keep a reference to the return value of \function{intern()}
-  around to benefit from it]{2.3}
-\end{funcdesc}
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
@@ -340,6 +340,21 @@ \section{\module{sys} ---
   \versionadded{1.5.2}
 \end{datadesc}
 
+\begin{funcdesc}{intern}{string}
+  Enter \var{string} in the table of ``interned'' strings and return
+  the interned string -- which is \var{string} itself or a copy.
+  Interning strings is useful to gain a little performance on
+  dictionary lookup -- if the keys in a dictionary are interned, and
+  the lookup key is interned, the key comparisons (after hashing) can
+  be done by a pointer compare instead of a string compare.  Normally,
+  the names used in Python programs are automatically interned, and
+  the dictionaries used to hold module, class or instance attributes
+  have interned keys.  \versionchanged[Interned strings are not
+  immortal (like they used to be in Python 2.2 and before);
+  you must keep a reference to the return value of \function{intern()}
+  around to benefit from it]{2.3}
+\end{funcdesc}
+
 \begin{datadesc}{last_type}
 \dataline{last_value}
 \dataline{last_traceback}
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
@@ -2700,7 +2700,7 @@ \section{The \function{dir()} Function \label{dir}}
  'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod',
  'enumerate', 'eval', 'exec', 'execfile', 'exit', 'file', 'filter', 'float',
  'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex',
- 'id', 'int', 'intern', 'isinstance', 'issubclass', 'iter',
+ 'id', 'int', 'isinstance', 'issubclass', 'iter',
  'len', 'license', 'list', 'locals', 'long', 'map', 'max', 'min',
  'object', 'oct', 'open', 'ord', 'pow', 'property', 'quit', 'range',
  'reload', 'repr', 'reversed', 'round', 'set',
diff --git a/Include/stringobject.h b/Include/stringobject.h
@@ -28,7 +28,7 @@ functions should be applied to nil objects.
    Interning strings (ob_sstate) tries to ensure that only one string
    object with a given value exists, so equality tests can be one pointer
    comparison.  This is generally restricted to strings that "look like"
-   Python identifiers, although the intern() builtin can be used to force
+   Python identifiers, although the sys.intern() function can be used to force
    interning of any string.
    Together, these sped the interpreter by up to 20%. */
 
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
@@ -842,30 +842,6 @@ def __int__(self):
         self.assertEqual(int(Foo4()), 42L)
         self.assertRaises(TypeError, int, Foo5())
 
-    def test_intern(self):
-        self.assertRaises(TypeError, intern)
-        s = "never interned before"
-        self.assert_(intern(s) is s)
-        s2 = s.swapcase().swapcase()
-        self.assert_(intern(s2) is s)
-
-        # Subclasses of string can't be interned, because they
-        # provide too much opportunity for insane things to happen.
-        # We don't want them in the interned dict and if they aren't
-        # actually interned, we don't want to create the appearance
-        # that they are by allowing intern() to succeeed.
-        class S(str):
-            def __hash__(self):
-                return 123
-
-        self.assertRaises(TypeError, intern, S("abc"))
-
-        # It's still safe to pass these strings to routines that
-        # call intern internally, e.g. PyObject_SetAttr().
-        s = S("abc")
-        setattr(s, s, s)
-        self.assertEqual(getattr(s, s), s)
-
     def test_iter(self):
         self.assertRaises(TypeError, iter)
         self.assertRaises(TypeError, iter, 42, 42)
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
@@ -350,6 +350,31 @@ def test_43581(self):
         # the test runs under regrtest.
         self.assert_(sys.__stdout__.encoding == sys.__stderr__.encoding)
 
+    def test_intern(self):
+        self.assertRaises(TypeError, sys.intern)
+        s = "never interned before"
+        self.assert_(sys.intern(s) is s)
+        s2 = s.swapcase().swapcase()
+        self.assert_(sys.intern(s2) is s)
+
+        # Subclasses of string can't be interned, because they
+        # provide too much opportunity for insane things to happen.
+        # We don't want them in the interned dict and if they aren't
+        # actually interned, we don't want to create the appearance
+        # that they are by allowing intern() to succeeed.
+        class S(str):
+            def __hash__(self):
+                return 123
+
+        self.assertRaises(TypeError, sys.intern, S("abc"))
+
+        # It's still safe to pass these strings to routines that
+        # call intern internally, e.g. PyObject_SetAttr().
+        s = S("abc")
+        setattr(s, s, s)
+        self.assertEqual(getattr(s, s), s)
+
+
 def test_main():
     test.test_support.run_unittest(SysModuleTest)
 
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -12,7 +12,7 @@ What's New in Python 3000?
 TO DO
 -----
 
-- See PEP 3000.
+- See PEP 3000, 3100.
 
 - Test merging certain changes from the 2.5 HEAD code.
 
@@ -36,7 +36,11 @@ TO DO
 Core and Builtins
 -----------------
 
-- Renamed nb_nonzero to nb_bool and __nonzero__ to __bool__
+- Moved intern() to sys.intern().
+
+- exec is now a function.
+
+- Renamed nb_nonzero to nb_bool and __nonzero__ to __bool__.
 
 - Classic classes are a thing of the past.  All classes are new style.
 
@@ -90,7 +94,7 @@ Core and Builtins
 - zip returns an iterator
 
 - Additions:
-  set literals
+  set literals, ellipsis literal
 
 
 Extension Modules
diff --git a/Misc/python-mode.el b/Misc/python-mode.el
@@ -382,7 +382,7 @@ support for features needed by `python-mode'.")
 			  "delattr" "dict" "dir" "divmod"
 			  "enumerate" "eval" "execfile" "exit" "file"
 			  "filter" "float" "getattr" "globals" "hasattr"
-			  "hash" "hex" "id" "int" "intern"
+			  "hash" "hex" "id" "int"
 			  "isinstance" "issubclass" "iter" "len" "license"
 			  "list" "locals" "long" "map" "max" "min" "object"
 			  "oct" "open" "ord" "pow" "property" "range"
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
@@ -1118,31 +1118,6 @@ PyDoc_STRVAR(hex_doc,
 Return the hexadecimal representation of an integer or long integer.");
 
 
-static PyObject *
-builtin_intern(PyObject *self, PyObject *args)
-{
-	PyObject *s;
-	if (!PyArg_ParseTuple(args, "S:intern", &s))
-		return NULL;
-	if (!PyString_CheckExact(s)) {
-		PyErr_SetString(PyExc_TypeError,
-				"can't intern subclass of string");
-		return NULL;
-	}
-	Py_INCREF(s);
-	PyString_InternInPlace(&s);
-	return s;
-}
-
-PyDoc_STRVAR(intern_doc,
-"intern(string) -> string\n\
-\n\
-``Intern'' the given string.  This enters the string in the (global)\n\
-table of interned strings whose purpose is to speed up dictionary lookups.\n\
-Return the string itself or the previously interned string object with the\n\
-same value.");
-
-
 static PyObject *
 builtin_iter(PyObject *self, PyObject *args)
 {
@@ -2069,7 +2044,6 @@ static PyMethodDef builtin_methods[] = {
  	{"hash",	builtin_hash,       METH_O, hash_doc},
  	{"hex",		builtin_hex,        METH_O, hex_doc},
  	{"id",		builtin_id,         METH_O, id_doc},
- 	{"intern",	builtin_intern,     METH_VARARGS, intern_doc},
  	{"isinstance",  builtin_isinstance, METH_VARARGS, isinstance_doc},
  	{"issubclass",  builtin_issubclass, METH_VARARGS, issubclass_doc},
  	{"iter",	builtin_iter,       METH_VARARGS, iter_doc},
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
@@ -264,6 +264,32 @@ operating system filenames."
 
 #endif
 
+
+static PyObject *
+sys_intern(PyObject *self, PyObject *args)
+{
+	PyObject *s;
+	if (!PyArg_ParseTuple(args, "S:intern", &s))
+		return NULL;
+	if (!PyString_CheckExact(s)) {
+		PyErr_SetString(PyExc_TypeError,
+				"can't intern subclass of string");
+		return NULL;
+	}
+	Py_INCREF(s);
+	PyString_InternInPlace(&s);
+	return s;
+}
+
+PyDoc_STRVAR(intern_doc,
+"intern(string) -> string\n\
+\n\
+``Intern'' the given string.  This enters the string in the (global)\n\
+table of interned strings whose purpose is to speed up dictionary lookups.\n\
+Return the string itself or the previously interned string object with the\n\
+same value.");
+
+
 /*
  * Cached interned string objects used for calling the profile and
  * trace functions.  Initialized by trace_init().
@@ -772,6 +798,7 @@ static PyMethodDef sys_methods[] = {
 	{"getwindowsversion", (PyCFunction)sys_getwindowsversion, METH_NOARGS,
 	 getwindowsversion_doc},
 #endif /* MS_WINDOWS */
+ 	{"intern",	sys_intern,     METH_VARARGS, intern_doc},
 #ifdef USE_MALLOPT
 	{"mdebug",	sys_mdebug, METH_VARARGS},
 #endif
diff --git a/Tools/pybench/Strings.py b/Tools/pybench/Strings.py
@@ -1,5 +1,6 @@
 from pybench import Test
 from string import join
+import sys
 
 class ConcatStrings(Test):
 
@@ -174,7 +175,7 @@ class CompareInternedStrings(Test):
     def test(self):
 
         # Make sure the strings *are* interned
-        s = intern(join(map(str,range(10))))
+        s = sys.intern(join(map(str,range(10))))
         t = s
 
         for i in xrange(self.rounds):
@@ -240,7 +241,7 @@ def test(self):
 
     def calibrate(self):
 
-        s = intern(join(map(str,range(10))))
+        s = sys.intern(join(map(str,range(10))))
         t = s
 
         for i in xrange(self.rounds):
diff --git a/Tools/scripts/fixdiv.py b/Tools/scripts/fixdiv.py
@@ -198,7 +198,7 @@ def readwarnings(warningsfile):
         list = warnings.get(filename)
         if list is None:
             warnings[filename] = list = []
-        list.append((int(lineno), intern(what)))
+        list.append((int(lineno), sys.intern(what)))
     f.close()
     return warnings
 
