portage.dep: Rewrite paren_reduce and add tests

2 files changed, 88 insertions, 53 deletions

diff --git a/pym/portage/dep/__init__.py b/pym/portage/dep/__init__.py
index 542c17680..19e347cfb 100644
--- a/pym/portage/dep/__init__.py
+++ b/pym/portage/dep/__init__.py
@@ -81,72 +81,61 @@ def strip_empty(myarr):
 	"""
 	return [x for x in myarr if x]
 
-_paren_whitespace_re = re.compile(r'\S(\(|\))|(\(|\))\S')
-
-def paren_reduce(mystr,tokenize=1):
+def paren_reduce(mystr):
 	"""
-	Take a string and convert all paren enclosed entities into sublists, optionally
-	futher splitting the list elements by spaces.
+	Take a string and convert all paren enclosed entities into sublists and
+	split the list elements by spaces.
 
 	Example usage:
-		>>> paren_reduce('foobar foo ( bar baz )',1)
+		>>> paren_reduce('foobar foo ( bar baz )')
 		['foobar', 'foo', ['bar', 'baz']]
-		>>> paren_reduce('foobar foo ( bar baz )',0)
-		['foobar foo ', [' bar baz ']]
 
 	@param mystr: The string to reduce
 	@type mystr: String
-	@param tokenize: Split on spaces to produces further list breakdown
-	@type tokenize: Integer
 	@rtype: Array
 	@return: The reduced string in an array
 	"""
-	global _dep_check_strict, _paren_whitespace_re
-	if _dep_check_strict:
-		m = _paren_whitespace_re.search(mystr)
-		if m is not None:
-			raise portage.exception.InvalidDependString(
-				_("missing space by parenthesis: '%s'") % m.group(0))
-	mylist = []
-	while mystr:
-		left_paren = mystr.find("(")
-		has_left_paren = left_paren != -1
-		right_paren = mystr.find(")")
-		has_right_paren = right_paren != -1
-		if not has_left_paren and not has_right_paren:
-			freesec = mystr
-			subsec = None
-			tail = ""
-		elif mystr[0] == ")":
-			return [mylist,mystr[1:]]
-		elif has_left_paren and not has_right_paren:
-			raise portage.exception.InvalidDependString(
-				_("missing right parenthesis: '%s'") % mystr)
-		elif has_left_paren and left_paren < right_paren:
-			freesec,subsec = mystr.split("(",1)
-			sublist = paren_reduce(subsec, tokenize=tokenize)
-			if len(sublist) != 2:
+	mysplit = mystr.split()
+	level = 0
+	stack = [[]]
+	need_bracket = False
+	
+	for token in mysplit:
+		if token == "(":
+			need_bracket = False
+			stack.append([])
+			level += 1
+		elif token == ")":
+			if need_bracket:
 				raise portage.exception.InvalidDependString(
 					_("malformed syntax: '%s'") % mystr)
-			subsec, tail = sublist
-		else:
-			subsec,tail = mystr.split(")",1)
-			if tokenize:
-				subsec = strip_empty(subsec.split(" "))
-				return [mylist+subsec,tail]
-			return mylist+[subsec],tail
-		if not isinstance(tail, basestring):
-			raise portage.exception.InvalidDependString(
-				_("malformed syntax: '%s'") % mystr)
-		mystr = tail
-		if freesec:
-			if tokenize:
-				mylist = mylist + strip_empty(freesec.split(" "))
+			if level > 0:
+				level -= 1
+				stack[level].append(stack.pop())
 			else:
-				mylist = mylist + [freesec]
-		if subsec is not None:
-			mylist = mylist + [subsec]
-	return mylist
+				raise portage.exception.InvalidDependString(
+					_("malformed syntax: '%s'") % mystr)
+		elif token == "||":
+			if need_bracket:
+				raise portage.exception.InvalidDependString(
+					_("malformed syntax: '%s'") % mystr)
+			need_bracket = True
+			stack[level].append(token)
+		else:
+			if need_bracket or "(" in token or ")" in token or "|" in token:
+				raise portage.exception.InvalidDependString(
+					_("malformed syntax: '%s'") % mystr)
+
+			if token[-1] == "?":
+				need_bracket = True
+			
+			stack[level].append(token)
+
+	if level != 0 or need_bracket:
+		raise portage.exception.InvalidDependString(
+			_("malformed syntax: '%s'") % mystr)
+	
+	return stack[0]
 
 class paren_normalize(list):
 	"""Take a dependency structure as returned by paren_reduce or use_reduce
diff --git a/pym/portage/tests/dep/test_paren_reduce.py b/pym/portage/tests/dep/test_paren_reduce.py
new file mode 100644
index 000000000..3277ab58b
--- /dev/null
+++ b/pym/portage/tests/dep/test_paren_reduce.py
@@ -0,0 +1,46 @@
+# Copyright 2010 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+from portage.tests import TestCase
+from portage.dep import paren_reduce
+from portage.exception import InvalidDependString
+
+class TestParenReduce(TestCase):
+
+	def testParenReduce(self):
+
+		test_cases = (
+			( "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"]]),
+		)
+		
+		test_cases_xfail = (
+			"( A",
+			"A )",
+
+			"||( A B )",
+			"|| (A B )",
+			"|| ( A B)",
+			"|| ( A B",
+			"|| A B )",
+
+			"|| A B",
+			"|| ( A B ) )",
+			"|| || B C",
+			
+			"|| ( A B || )",
+			
+			"a? A",
+		)
+
+		for dep_str, expected_result in test_cases:
+			self.assertEqual(paren_reduce(dep_str), expected_result)
+
+		for dep_str in test_cases_xfail:
+			self.assertRaisesMsg(dep_str,
+				InvalidDependString, paren_reduce, dep_str)