From 7e5baff5b998e02c39a7f64c079a0992651557ec Mon Sep 17 00:00:00 2001
From: Mahmoud Hashemi <mahmoud@hatnote.com>
Date: Thu, 16 Apr 2015 02:18:01 -0700
Subject: [PATCH] moved make_sentinel into typeutils and deleted the confusing
 compat module

---
 boltons/cacheutils.py |  2 +-
 boltons/compat.py     | 37 -------------------------------------
 boltons/dictutils.py  |  2 +-
 boltons/listutils.py  |  2 +-
 boltons/queueutils.py |  2 +-
 boltons/setutils.py   |  2 +-
 boltons/tableutils.py |  2 +-
 boltons/typeutils.py  | 35 +++++++++++++++++++++++++++++++++++
 8 files changed, 41 insertions(+), 43 deletions(-)
 delete mode 100644 boltons/compat.py

diff --git a/boltons/cacheutils.py b/boltons/cacheutils.py
index 84d23d5..7aff49e 100644
--- a/boltons/cacheutils.py
+++ b/boltons/cacheutils.py
@@ -49,7 +49,7 @@ except:
             pass
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _MISSING = make_sentinel(var_name='_MISSING')
     _KWARG_MARK = make_sentinel(var_name='_KWARG_MARK')
 except ImportError:
diff --git a/boltons/compat.py b/boltons/compat.py
deleted file mode 100644
index 8362274..0000000
--- a/boltons/compat.py
+++ /dev/null
@@ -1,37 +0,0 @@
-# -*- coding: utf-8 -*-
-
-import sys
-
-IS_PY2 = sys.version_info[0] == 2
-IS_PY3 = sys.version_info[0] == 3
-
-
-if IS_PY2:
-    from StringIO import StringIO
-    unicode, str, bytes, basestring = unicode, str, str, basestring
-    xrange = xrange
-    lrange = range
-elif IS_PY3:
-    from io import StringIO
-    unicode, str, bytes, basestring = str, bytes, bytes, str
-    xrange = range
-    lrange = lambda *args: list(range(*args))
-else:
-    raise NotImplementedError('welcome to the future, I guess. (report this)')
-
-
-def make_sentinel(name='_MISSING', var_name=None):
-    class Sentinel(object):
-        def __init__(self):
-            self.name = name
-            self.var_name = var_name
-        def __repr__(self):
-            if self.var_name:
-                return self.var_name
-            return '%s(%r)' % (self.__class__.__name__, self.name)
-        if var_name:
-            def __reduce__(self):
-                return self.var_name
-        def __nonzero__(self):
-            return False
-    return Sentinel()
diff --git a/boltons/dictutils.py b/boltons/dictutils.py
index 13d1e9b..40f69a7 100644
--- a/boltons/dictutils.py
+++ b/boltons/dictutils.py
@@ -42,7 +42,7 @@ except ImportError:
     izip = zip  # Python 3
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _MISSING = make_sentinel(var_name='_MISSING')
 except ImportError:
     _MISSING = object()
diff --git a/boltons/listutils.py b/boltons/listutils.py
index ce914c6..4810feb 100644
--- a/boltons/listutils.py
+++ b/boltons/listutils.py
@@ -16,7 +16,7 @@ from math import log as math_log
 from itertools import chain, islice
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _MISSING = make_sentinel(var_name='_MISSING')
 except ImportError:
     _MISSING = object()
diff --git a/boltons/queueutils.py b/boltons/queueutils.py
index 5bb8e01..92fd9ba 100644
--- a/boltons/queueutils.py
+++ b/boltons/queueutils.py
@@ -34,7 +34,7 @@ from bisect import insort
 import itertools
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _REMOVED = make_sentinel(var_name='_REMOVED')
 except ImportError:
     _REMOVED = object()
diff --git a/boltons/setutils.py b/boltons/setutils.py
index 5f51184..9f9d59c 100644
--- a/boltons/setutils.py
+++ b/boltons/setutils.py
@@ -18,7 +18,7 @@ from collections import MutableSet
 import operator
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _MISSING = make_sentinel(var_name='_MISSING')
 except ImportError:
     _MISSING = object()
diff --git a/boltons/tableutils.py b/boltons/tableutils.py
index a8e523c..4811a8e 100644
--- a/boltons/tableutils.py
+++ b/boltons/tableutils.py
@@ -32,7 +32,7 @@ except:
     string_types, integer_types = (str, bytes), (int,)
 
 try:
-    from compat import make_sentinel
+    from typeutils import make_sentinel
     _MISSING = make_sentinel(var_name='_MISSING')
 except ImportError:
     _MISSING = object()
diff --git a/boltons/typeutils.py b/boltons/typeutils.py
index 53f6b6a..d0c5c4d 100644
--- a/boltons/typeutils.py
+++ b/boltons/typeutils.py
@@ -10,6 +10,41 @@ from collections import deque
 _issubclass = issubclass
 
 
+def make_sentinel(name='_MISSING', var_name=None):
+    """Creates and returns a new instance of a new class, suitable for
+    usage as a "sentinel", a kind of singleton often used to indicate
+    a value is missing when ``None`` is a valid input.
+
+    Args:
+        name (str): Name of the Sentinel, used in ``__repr__``s
+        var_name (str): Set this name to the name of the variable in
+            its respective module enable pickleability.
+
+    >>> make_sentinel(var_name='_MISSING')
+    _MISSING
+
+    The most common use cases here in boltons are as default values
+    for optional function arguments, partly because of its
+    less-confusing appearance in automatically generated
+    documentation. Sentinels also function well as placeholders in queues
+    and linked lists.
+    """
+    class Sentinel(object):
+        def __init__(self):
+            self.name = name
+            self.var_name = var_name
+        def __repr__(self):
+            if self.var_name:
+                return self.var_name
+            return '%s(%r)' % (self.__class__.__name__, self.name)
+        if var_name:
+            def __reduce__(self):
+                return self.var_name
+        def __nonzero__(self):
+            return False
+    return Sentinel()
+
+
 def issubclass(subclass, baseclass):
     """Just like the built-in :func:`issubclass`, this function checks
     whether *subclass* is inherited from *baseclass*. Unlike the