No more dict-hackery for the dependencies

1 files changed, 151 insertions, 0 deletions

diff --git a/portato/dependency.py b/portato/dependency.py
new file mode 100644
index 0000000..718906f
--- /dev/null
+++ b/portato/dependency.py
@@ -0,0 +1,151 @@
+# -*- coding: utf-8 -*-
+#
+# File: portato/dependency.py
+# This file is part of the Portato-Project, a graphical portage-frontend.
+#
+# Copyright (C) 2008 René 'Necoro' Neumann
+# This is free software.  You may redistribute copies of it under the terms of
+# the GNU General Public License version 2.
+# There is NO WARRANTY, to the extent permitted by law.
+#
+# Written by René 'Necoro' Neumann <necoro@necoro.net>
+
+from __future__ import absolute_import, with_statement
+
+from .helper import debug
+
+"""
+Provides classes for the presentation of dependencies.
+"""
+__docformat__ = "restructuredtext"
+
+class Dependency (object):
+
+	"""
+	A simple dependency as it also is noted inside ebuilds.
+
+	:IVariables:
+
+		dep : string
+			The dependency string. It is immutable.
+	"""
+
+	def __init__ (self, dep):
+		"""
+		Creates a dependency out of a dep string.
+
+		:param dep: dependency string
+		:type dep: string
+		"""
+		self.__dep = dep
+
+	def __cmp__ (self, b):
+		return cmp(self.dep, b.dep)
+
+	def __hash__ (self):
+		return hash(self.dep)
+
+	def __str__ (self):
+		return "<Dependency '%s'>" % self.dep
+
+	__repr__ = __str__
+
+	def __get_dep (self):
+		return self.__dep
+
+	dep = property(__get_dep)
+
+class OrDependency (Dependency):
+
+	"""
+	Dependency representing an "or".
+	
+	:note: Order is important. ``|| ( a b )`` != ``|| ( b a )``
+
+	:IVariables:
+
+		dep : tuple(string,...)
+			The dependency strings. The tuple and the strings are immutable.
+	"""
+
+	def __init__ (self, deps):
+		"""
+		Creates an or-dependency out of a list (or tuple) of deps.
+
+		:param deps: The or'ed dependencies.
+		:type deps: iter<string>
+		"""
+
+		self.__dep = tuple(Dependency(dep) for dep in deps)
+	
+	def __str__ (self):
+		return "<|| %s>" % str(self.dep)
+	
+	__repr__ = __str__
+
+class DependencyTree (object):
+
+	"""
+	The DependencyTree shows all dependencies for a package and shows which useflags want which dependencies.
+
+	:IVariables:
+
+		deps : set(`Dependency`)
+			The list of dependencies which are not dependent on a useflag.
+
+		flags : dict(string -> `DependencyTree`)
+			Holds the additional dependency trees per useflag.
+	"""
+
+	def __init__ (self):
+
+		self.deps = set()
+		self.flags = {}
+
+	def add (self, dep, *moredeps):
+		"""
+		Adds one or more normal dependencies to the tree.
+
+		:Parameters:
+
+			dep : string
+				A dependency string.
+
+			moredeps
+				More parameters are allowed :)
+		"""
+		self.deps.add(Dependency(dep))
+
+		for dep in moredeps:
+			self.deps.add(Dependency(dep))
+
+	def add_or (self, orlist):
+		"""
+		Adds a list of dependencies, which are or'ed.
+
+		:param orlist: the dependency list
+		:type orlist: iter<string>
+		"""
+		self.deps.add(OrDependency(orlist))
+
+	def add_flag (self, flag):
+		"""
+		Adds a new useflag to this tree.
+		For convenience the newly created sub-tree is returned.
+
+		:param flag: the new flag
+		:rtype: `DependencyTree`
+		"""
+		if not flag in self.flags:
+			self.flags[flag] = DependencyTree()
+
+		return self.get_flag_tree(flag)
+
+	def get_flag_tree (self, flag):
+		"""
+		Returns the sub-tree of a specific tree.
+
+		:raises KeyError: if the flag is not (yet) in this tree
+		:rtype: `DependencyTree`
+		"""
+		return self.flags[flag]