[gentoo-commits] proj/gentoopm:master commit in: gentoopm/

["Michał Górny" <mgorny@gentoo.org>]

commit:     337953535fecf3ea86579537415bb598e6df2388
Author:     Michał Górny <mgorny <AT> gentoo <DOT> org>
AuthorDate: Thu Jul 21 22:24:41 2011 +0000
Commit:     Michał Górny <mgorny <AT> gentoo <DOT> org>
CommitDate: Thu Jul 21 22:24:41 2011 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/gentoopm.git;a=commit;h=33795353

Add an EnumTuple type.

---
 gentoopm/util.py |   35 +++++++++++++++++++++++++++++++++++
 1 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/gentoopm/util.py b/gentoopm/util.py
index 17a8d81..3005d36 100644
--- a/gentoopm/util.py
+++ b/gentoopm/util.py
@@ -7,6 +7,7 @@
 Utility functions for gentoopm.
 """
 
+import collections
 from abc import ABCMeta
 
 try:
@@ -118,3 +119,37 @@ class SpaceSepTuple(tuple):
 
 	def __str__(self):
 		return ' '.join(self)
+
+def EnumTuple(name, *keys):
+	"""
+	Create a namedtuple factory for an enumerated type. The resulting factory
+	function shall be called with keyword argument with names resembling
+	enumerated value names and values evaluating to True or False.
+
+	>>> MyTestEnum = EnumTuple('MyTestEnum', 'bad', 'good')
+	>>> i = 4
+	>>> MyTestEnum(bad = i <= 3, good = i > 3)
+	MyTestEnum(bad=False, good=True)
+
+	@param name: name of the resulting namedtuple
+	@type name: string
+	@param keys: list of enumerated values
+	@type keys: strings
+	@return: Factory function creating namedtuples.
+	@rtype: func(**kwargs)
+	"""
+
+	def _check_args(kwargs):
+		res = False
+		for a in kwargs.values():
+			if not isinstance(a, bool):
+				raise ValueError('Non-bool passed to EnumTuple')
+			if a and res:
+				raise ValueError('More than a single True passed to EnumTuple')
+			res |= a
+		if not res:
+			raise ValueError('All values passed to EnumTuple are False')
+		return kwargs
+
+	nt = collections.namedtuple(name, keys)
+	return lambda **kwargs: nt(**_check_args(kwargs))