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

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

[Michał Górny]

commit:     b2514c4e3a7ef40ec636eb04307247356bf3d87b
Author:     Michał Górny <mgorny <AT> gentoo <DOT> org>
AuthorDate: Sun Jul 10 07:54:39 2011 +0000
Commit:     Michał Górny <mgorny <AT> gentoo <DOT> org>
CommitDate: Sun Jul 10 07:54:39 2011 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/gentoopm.git;a=commit;h=b2514c4e

Start introducing custom exceptions.

---
 gentoopm/basepm/pkg.py    |   17 +++++++++--------
 gentoopm/exceptions.py    |   23 +++++++++++++++++++++++
 gentoopm/paludispm/pkg.py |    5 +++--
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/gentoopm/basepm/pkg.py b/gentoopm/basepm/pkg.py
index 5efa45e..b1f8e7d 100644
--- a/gentoopm/basepm/pkg.py
+++ b/gentoopm/basepm/pkg.py
@@ -6,6 +6,7 @@
 from abc import abstractmethod, abstractproperty
 
 from gentoopm.basepm.atom import PMAtom
+from gentoopm.exceptions import EmptyPackageSetError, AmbiguousPackageSetError
 from gentoopm.util import ABCObject
 
 class PMPackageSet(ABCObject):
@@ -47,11 +48,11 @@ class PMPackageSet(ABCObject):
 		try:
 			best = l[0]
 		except IndexError:
-			raise TypeError('.best called on an empty set')
+			raise EmptyPackageSetError('.best called on an empty set')
 
 		for p in l:
 			if p.key != best.key:
-				raise KeyError('.best called on a set of differently-named packages')
+				raise AmbiguousPackageSetError('.best called on a set of differently-named packages')
 		return best
 
 	def select(self, *args, **kwargs):
@@ -62,10 +63,10 @@ class PMPackageSet(ABCObject):
 		"""
 		try:
 			return self.filter(*args, **kwargs).best
-		except TypeError:
-			raise KeyError('No packages match the filters.')
-		except KeyError:
-			raise ValueError('Ambiguous filter (matches more than a single package name).')
+		except EmptyPackageSetError:
+			raise EmptyPackageSetError('No packages match the filters.')
+		except AmbiguousPackageSetError:
+			raise AmbiguousPackageSetError('Ambiguous filter (matches more than a single package name).')
 
 	def __getitem__(self, filt):
 		"""
@@ -82,13 +83,13 @@ class PMPackageSet(ABCObject):
 		try:
 			ret = next(it)
 		except StopIteration:
-			raise KeyError('No packages match the filter.')
+			raise EmptyPackageSetError('No packages match the filter.')
 		try:
 			next(it)
 		except StopIteration:
 			pass
 		else:
-			raise ValueError('Filter matches more than one package.')
+			raise AmbiguousPackageSetError('Filter matches more than one package.')
 
 		return ret
 

diff --git a/gentoopm/exceptions.py b/gentoopm/exceptions.py
new file mode 100644
index 0000000..7aa237f
--- /dev/null
+++ b/gentoopm/exceptions.py
@@ -0,0 +1,23 @@
+#!/usr/bin/python
+#	vim:fileencoding=utf-8
+# (c) 2011 Michał Górny <mgorny@gentoo.org>
+# Released under the terms of the 2-clause BSD license.
+
+class PMException(Exception):
+	"""
+	A base class for exceptions.
+	"""
+	pass
+
+class EmptyPackageSetError(PMException):
+	"""
+	Empty set passed to a function requiring a non-empty one.
+	"""
+	pass
+
+class AmbiguousPackageSetError(PMException):
+	"""
+	Ambiguous package set passed, e.g. containing multiple package names when
+	consistenly-named set was expected.
+	"""
+	pass

diff --git a/gentoopm/paludispm/pkg.py b/gentoopm/paludispm/pkg.py
index 5f40984..8907c15 100644
--- a/gentoopm/paludispm/pkg.py
+++ b/gentoopm/paludispm/pkg.py
@@ -8,6 +8,7 @@ import paludis
 from gentoopm.basepm.metadata import PMPackageMetadata
 from gentoopm.basepm.pkg import PMPackageSet, PMPackage, \
 		PMFilteredPackageSet
+from gentoopm.exceptions import EmptyPackageSetError, AmbiguousPackageSetError
 
 class PaludisPackageSet(PMPackageSet):
 	_sorted = False
@@ -23,10 +24,10 @@ class PaludisPackageSet(PMPackageSet):
 			try:
 				f = next(it)
 			except StopIteration:
-				raise TypeError('.best called on an empty set')
+				raise EmptyPackageSetError('.best called on an empty set')
 			for p in it:
 				if p.key != f.key:
-					raise KeyError('.best called on a set of differently-named packages')
+					raise AmbiguousPackageSetError('.best called on a set of differently-named packages')
 
 			try:
 				return p