From 3b3178a9c9ef56f658ca07dc526e0409ce1cd3df Mon Sep 17 00:00:00 2001
From: Sebastian Luther <SebastianLuther@gmx.de>
Date: Tue, 10 Aug 2010 10:10:58 +0200
Subject: [PATCH] portage.dep.paren_reduce: Remove redundant brackets

---
 pym/portage/dep/__init__.py                | 27 ++++++++++++++++++----
 pym/portage/tests/dep/test_paren_reduce.py | 16 ++++++++++++-
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/pym/portage/dep/__init__.py b/pym/portage/dep/__init__.py
index 19e347cfb..89b384a5b 100644
--- a/pym/portage/dep/__init__.py
+++ b/pym/portage/dep/__init__.py
@@ -84,11 +84,11 @@ def strip_empty(myarr):
 def paren_reduce(mystr):
 	"""
 	Take a string and convert all paren enclosed entities into sublists and
-	split the list elements by spaces.
+	split the list elements by spaces. All redundant brackets are removed.
 
 	Example usage:
-		>>> paren_reduce('foobar foo ( bar baz )')
-		['foobar', 'foo', ['bar', 'baz']]
+		>>> paren_reduce('foobar foo? ( bar baz )')
+		['foobar', 'foo?', ['bar', 'baz']]
 
 	@param mystr: The string to reduce
 	@type mystr: String
@@ -111,7 +111,26 @@ def paren_reduce(mystr):
 					_("malformed syntax: '%s'") % mystr)
 			if level > 0:
 				level -= 1
-				stack[level].append(stack.pop())
+				l = stack.pop()
+				if l:
+					if not stack[level] or (stack[level][-1] != "||" and not stack[level][-1][-1] == "?"):
+						#Optimize: ( ( ... ) ) -> ( ... )
+						stack[level].extend(l)
+					elif len(l) == 1 and stack[level][-1] == "||":
+						#Optimize: || ( A ) -> A
+						stack[level].pop()
+						stack[level].extend(l)
+					elif len(l) == 2 and (l[0] == "||" or l[0][-1] == "?") and stack[level][-1] in (l[0], "||"):
+						#Optimize: 	|| ( || ( ... ) ) -> || ( ... )
+						#			foo? ( foo? ( ... ) ) -> foo? ( ... )
+						#			|| ( foo? ( ... ) ) -> foo? ( ... )
+						stack[level].pop()
+						stack[level].extend(l)
+					else:
+						stack[level].append(l)
+				else:
+					if stack[level] and (stack[level][-1] == "||" or stack[level][-1][-1] == "?"):
+						stack[level].pop()
 			else:
 				raise portage.exception.InvalidDependString(
 					_("malformed syntax: '%s'") % mystr)
diff --git a/pym/portage/tests/dep/test_paren_reduce.py b/pym/portage/tests/dep/test_paren_reduce.py
index 3277ab58b..bd5f42584 100644
--- a/pym/portage/tests/dep/test_paren_reduce.py
+++ b/pym/portage/tests/dep/test_paren_reduce.py
@@ -11,12 +11,23 @@ class TestParenReduce(TestCase):
 
 		test_cases = (
 			( "A", ["A"]),
-			( "( A )", [["A"]]),
+			( "( A )", ["A"]),
 			( "|| ( A B )", [ "||", ["A", "B"] ]),
 			( "|| ( A || ( B C ) )", [ "||", ["A", "||", ["B", "C"]]]),
 			( "|| ( A || ( B C D ) )", [ "||", ["A", "||", ["B", "C", "D"]] ]),
 			( "|| ( A || ( B || ( C D ) E ) )", [ "||", ["A", "||", ["B", "||", ["C", "D"], "E"]] ]),
 			( "a? ( A )", ["a?", ["A"]]),
+			
+			( "( || ( ( ( A ) B ) ) )", [ "||", ["A", "B"] ]),
+			( "( || ( || ( ( A ) B ) ) )", [ "||", ["A", "B"] ]),
+			( "( || ( || ( ( A ) B ) ) )", [ "||", ["A", "B"] ]),
+			( "|| ( A )", ["A"]),
+			( "( || ( || ( || ( A ) foo? ( B ) ) ) )", [ "||", ["A", "foo?", ["B"] ]]),
+			( "( || ( || ( bar? ( A ) || ( foo? ( B ) ) ) ) )", [ "||", ["bar?", ["A"], "foo?", ["B"] ]]),
+			( "A || ( ) foo? ( ) B", ["A", "B"]),
+
+			( "|| ( A ) || ( B )", ["A", "B"]),
+			( "foo? ( A ) foo? ( B )", ["foo?", ["A"], "foo?", ["B"]]),
 		)
 		
 		test_cases_xfail = (
@@ -36,6 +47,9 @@ class TestParenReduce(TestCase):
 			"|| ( A B || )",
 			
 			"a? A",
+			
+			( "( || ( || || ( A ) foo? ( B ) ) )"),
+			( "( || ( || bar? ( A ) foo? ( B ) ) )"),
 		)
 
 		for dep_str, expected_result in test_cases:
-- 
2.26.2