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+++ b/genshi/template/tests/eval.py
@@ -0,0 +1,389 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2006 Edgewall Software
+# All rights reserved.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://genshi.edgewall.org/wiki/License.
+#
+# This software consists of voluntary contributions made by many
+# individuals. For the exact contribution history, see the revision
+# history and logs, available at http://genshi.edgewall.org/log/.
+
+import doctest
+import sys
+import unittest
+
+from genshi.template.eval import Expression, Undefined
+
+
+class ExpressionTestCase(unittest.TestCase):
+
+    def test_name_lookup(self):
+        self.assertEqual('bar', Expression('foo').evaluate({'foo': 'bar'}))
+        self.assertEqual(id, Expression('id').evaluate({}, nocall=True))
+        self.assertEqual('bar', Expression('id').evaluate({'id': 'bar'}))
+        self.assertEqual(None, Expression('id').evaluate({'id': None},
+                                                         nocall=True))
+
+    def test_str_literal(self):
+        self.assertEqual('foo', Expression('"foo"').evaluate({}))
+        self.assertEqual('foo', Expression('"""foo"""').evaluate({}))
+        self.assertEqual('foo', Expression("'foo'").evaluate({}))
+        self.assertEqual('foo', Expression("'''foo'''").evaluate({}))
+        self.assertEqual('foo', Expression("u'foo'").evaluate({}))
+        self.assertEqual('foo', Expression("r'foo'").evaluate({}))
+
+    def test_str_literal_non_ascii(self):
+        expr = Expression(u"u'\xfe'")
+        self.assertEqual(u'þ', expr.evaluate({}))
+        expr = Expression("u'\xfe'")
+        self.assertEqual(u'þ', expr.evaluate({}))
+        expr = Expression("'\xc3\xbe'")
+        self.assertEqual(u'þ', expr.evaluate({}))
+
+    def test_num_literal(self):
+        self.assertEqual(42, Expression("42").evaluate({}))
+        self.assertEqual(42L, Expression("42L").evaluate({}))
+        self.assertEqual(.42, Expression(".42").evaluate({}))
+        self.assertEqual(07, Expression("07").evaluate({}))
+        self.assertEqual(0xF2, Expression("0xF2").evaluate({}))
+        self.assertEqual(0XF2, Expression("0XF2").evaluate({}))
+
+    def test_dict_literal(self):
+        self.assertEqual({}, Expression("{}").evaluate({}))
+        self.assertEqual({'key': True},
+                         Expression("{'key': value}").evaluate({'value': True}))
+
+    def test_list_literal(self):
+        self.assertEqual([], Expression("[]").evaluate({}))
+        self.assertEqual([1, 2, 3], Expression("[1, 2, 3]").evaluate({}))
+        self.assertEqual([True],
+                         Expression("[value]").evaluate({'value': True}))
+
+    def test_tuple_literal(self):
+        self.assertEqual((), Expression("()").evaluate({}))
+        self.assertEqual((1, 2, 3), Expression("(1, 2, 3)").evaluate({}))
+        self.assertEqual((True,),
+                         Expression("(value,)").evaluate({'value': True}))
+
+    def test_unaryop_pos(self):
+        self.assertEqual(1, Expression("+1").evaluate({}))
+        self.assertEqual(1, Expression("+x").evaluate({'x': 1}))
+
+    def test_unaryop_neg(self):
+        self.assertEqual(-1, Expression("-1").evaluate({}))
+        self.assertEqual(-1, Expression("-x").evaluate({'x': 1}))
+
+    def test_unaryop_not(self):
+        self.assertEqual(False, Expression("not True").evaluate({}))
+        self.assertEqual(False, Expression("not x").evaluate({'x': True}))
+
+    def test_unaryop_inv(self):
+        self.assertEqual(-2, Expression("~1").evaluate({}))
+        self.assertEqual(-2, Expression("~x").evaluate({'x': 1}))
+
+    def test_binop_add(self):
+        self.assertEqual(3, Expression("2 + 1").evaluate({}))
+        self.assertEqual(3, Expression("x + y").evaluate({'x': 2, 'y': 1}))
+
+    def test_binop_sub(self):
+        self.assertEqual(1, Expression("2 - 1").evaluate({}))
+        self.assertEqual(1, Expression("x - y").evaluate({'x': 1, 'y': 1}))
+
+    def test_binop_sub(self):
+        self.assertEqual(1, Expression("2 - 1").evaluate({}))
+        self.assertEqual(1, Expression("x - y").evaluate({'x': 2, 'y': 1}))
+
+    def test_binop_mul(self):
+        self.assertEqual(4, Expression("2 * 2").evaluate({}))
+        self.assertEqual(4, Expression("x * y").evaluate({'x': 2, 'y': 2}))
+
+    def test_binop_pow(self):
+        self.assertEqual(4, Expression("2 ** 2").evaluate({}))
+        self.assertEqual(4, Expression("x ** y").evaluate({'x': 2, 'y': 2}))
+
+    def test_binop_div(self):
+        self.assertEqual(2, Expression("4 / 2").evaluate({}))
+        self.assertEqual(2, Expression("x / y").evaluate({'x': 4, 'y': 2}))
+
+    def test_binop_floordiv(self):
+        self.assertEqual(1, Expression("3 // 2").evaluate({}))
+        self.assertEqual(1, Expression("x // y").evaluate({'x': 3, 'y': 2}))
+
+    def test_binop_mod(self):
+        self.assertEqual(1, Expression("3 % 2").evaluate({}))
+        self.assertEqual(1, Expression("x % y").evaluate({'x': 3, 'y': 2}))
+
+    def test_binop_and(self):
+        self.assertEqual(0, Expression("1 & 0").evaluate({}))
+        self.assertEqual(0, Expression("x & y").evaluate({'x': 1, 'y': 0}))
+
+    def test_binop_or(self):
+        self.assertEqual(1, Expression("1 | 0").evaluate({}))
+        self.assertEqual(1, Expression("x | y").evaluate({'x': 1, 'y': 0}))
+
+    def test_binop_contains(self):
+        self.assertEqual(True, Expression("1 in (1, 2, 3)").evaluate({}))
+        self.assertEqual(True, Expression("x in y").evaluate({'x': 1,
+                                                              'y': (1, 2, 3)}))
+
+    def test_binop_not_contains(self):
+        self.assertEqual(True, Expression("4 not in (1, 2, 3)").evaluate({}))
+        self.assertEqual(True, Expression("x not in y").evaluate({'x': 4,
+                                                                  'y': (1, 2, 3)}))
+
+    def test_binop_is(self):
+        self.assertEqual(True, Expression("1 is 1").evaluate({}))
+        self.assertEqual(True, Expression("x is y").evaluate({'x': 1, 'y': 1}))
+        self.assertEqual(False, Expression("1 is 2").evaluate({}))
+        self.assertEqual(False, Expression("x is y").evaluate({'x': 1, 'y': 2}))
+
+    def test_binop_is_not(self):
+        self.assertEqual(True, Expression("1 is not 2").evaluate({}))
+        self.assertEqual(True, Expression("x is not y").evaluate({'x': 1,
+                                                                  'y': 2}))
+        self.assertEqual(False, Expression("1 is not 1").evaluate({}))
+        self.assertEqual(False, Expression("x is not y").evaluate({'x': 1,
+                                                                   'y': 1}))
+
+    def test_boolop_and(self):
+        self.assertEqual(False, Expression("True and False").evaluate({}))
+        self.assertEqual(False, Expression("x and y").evaluate({'x': True,
+                                                                'y': False}))
+
+    def test_boolop_or(self):
+        self.assertEqual(True, Expression("True or False").evaluate({}))
+        self.assertEqual(True, Expression("x or y").evaluate({'x': True,
+                                                              'y': False}))
+
+    def test_compare_eq(self):
+        self.assertEqual(True, Expression("1 == 1").evaluate({}))
+        self.assertEqual(True, Expression("x == y").evaluate({'x': 1, 'y': 1}))
+
+    def test_compare_ne(self):
+        self.assertEqual(False, Expression("1 != 1").evaluate({}))
+        self.assertEqual(False, Expression("x != y").evaluate({'x': 1, 'y': 1}))
+        self.assertEqual(False, Expression("1 <> 1").evaluate({}))
+        self.assertEqual(False, Expression("x <> y").evaluate({'x': 1, 'y': 1}))
+
+    def test_compare_lt(self):
+        self.assertEqual(True, Expression("1 < 2").evaluate({}))
+        self.assertEqual(True, Expression("x < y").evaluate({'x': 1, 'y': 2}))
+
+    def test_compare_le(self):
+        self.assertEqual(True, Expression("1 <= 1").evaluate({}))
+        self.assertEqual(True, Expression("x <= y").evaluate({'x': 1, 'y': 1}))
+
+    def test_compare_gt(self):
+        self.assertEqual(True, Expression("2 > 1").evaluate({}))
+        self.assertEqual(True, Expression("x > y").evaluate({'x': 2, 'y': 1}))
+
+    def test_compare_ge(self):
+        self.assertEqual(True, Expression("1 >= 1").evaluate({}))
+        self.assertEqual(True, Expression("x >= y").evaluate({'x': 1, 'y': 1}))
+
+    def test_compare_multi(self):
+        self.assertEqual(True, Expression("1 != 3 == 3").evaluate({}))
+        self.assertEqual(True, Expression("x != y == y").evaluate({'x': 1,
+                                                                   'y': 3}))
+
+    def test_call_function(self):
+        self.assertEqual(42, Expression("foo()").evaluate({'foo': lambda: 42}))
+        data = {'foo': 'bar'}
+        self.assertEqual('BAR', Expression("foo.upper()").evaluate(data))
+        data = {'foo': {'bar': range(42)}}
+        self.assertEqual(42, Expression("len(foo.bar)").evaluate(data))
+
+    def test_call_keywords(self):
+        self.assertEqual(42, Expression("foo(x=bar)").evaluate({'foo': lambda x: x,
+                                                                'bar': 42}))
+
+    def test_call_star_args(self):
+        self.assertEqual(42, Expression("foo(*bar)").evaluate({'foo': lambda x: x,
+                                                               'bar': [42]}))
+
+    def test_call_dstar_args(self):
+        def foo(x):
+            return x
+        self.assertEqual(42, Expression("foo(**bar)").evaluate({'foo': foo,
+                                                                'bar': {"x": 42}}))
+
+    def test_call_function_without_params(self):
+        self.assertEqual(42, Expression("foo").evaluate({'foo': lambda: 42}))
+        data = {'foo': 'bar'}
+        self.assertEqual('BAR', Expression("foo.upper").evaluate(data))
+        data = {'foo': {'bar': range(42)}}
+
+    def test_lambda(self):
+        # Define a custom `sorted` function cause the builtin isn't available
+        # on Python 2.3
+        def sorted(items, compfunc):
+            items.sort(compfunc)
+            return items
+        data = {'items': [{'name': 'b', 'value': 0}, {'name': 'a', 'value': 1}],
+                'sorted': sorted}
+        expr = Expression("sorted(items, lambda a, b: cmp(a.name, b.name))")
+        self.assertEqual([{'name': 'a', 'value': 1}, {'name': 'b', 'value': 0}],
+                         expr.evaluate(data))
+
+    def test_list_comprehension(self):
+        expr = Expression("[n for n in numbers if n < 2]")
+        self.assertEqual([0, 1], expr.evaluate({'numbers': range(5)}))
+
+        expr = Expression("[(i, n + 1) for i, n in enumerate(numbers)]")
+        self.assertEqual([(0, 1), (1, 2), (2, 3), (3, 4), (4, 5)],
+                         expr.evaluate({'numbers': range(5)}))
+
+        expr = Expression("[offset + n for n in numbers]")
+        self.assertEqual([2, 3, 4, 5, 6],
+                         expr.evaluate({'numbers': range(5), 'offset': 2}))
+
+    def test_list_comprehension_with_getattr(self):
+        items = [{'name': 'a', 'value': 1}, {'name': 'b', 'value': 2}]
+        expr = Expression("[i.name for i in items if i.value > 1]")
+        self.assertEqual(['b'], expr.evaluate({'items': items}))
+
+    def test_list_comprehension_with_getitem(self):
+        items = [{'name': 'a', 'value': 1}, {'name': 'b', 'value': 2}]
+        expr = Expression("[i['name'] for i in items if i['value'] > 1]")
+        self.assertEqual(['b'], expr.evaluate({'items': items}))
+
+    if sys.version_info >= (2, 4):
+        # Generator expressions only supported in Python 2.4 and up
+
+        def test_generator_expression(self):
+            expr = Expression("list(n for n in numbers if n < 2)")
+            self.assertEqual([0, 1], expr.evaluate({'numbers': range(5)}))
+
+            expr = Expression("list((i, n + 1) for i, n in enumerate(numbers))")
+            self.assertEqual([(0, 1), (1, 2), (2, 3), (3, 4), (4, 5)],
+                             expr.evaluate({'numbers': range(5)}))
+
+            expr = Expression("list(offset + n for n in numbers)")
+            self.assertEqual([2, 3, 4, 5, 6],
+                             expr.evaluate({'numbers': range(5), 'offset': 2}))
+
+        def test_generator_expression_with_getattr(self):
+            items = [{'name': 'a', 'value': 1}, {'name': 'b', 'value': 2}]
+            expr = Expression("list(i.name for i in items if i.value > 1)")
+            self.assertEqual(['b'], expr.evaluate({'items': items}))
+
+        def test_generator_expression_with_getitem(self):
+            items = [{'name': 'a', 'value': 1}, {'name': 'b', 'value': 2}]
+            expr = Expression("list(i['name'] for i in items if i['value'] > 1)")
+            self.assertEqual(['b'], expr.evaluate({'items': items}))
+
+    def test_slice(self):
+        expr = Expression("numbers[0:2]")
+        self.assertEqual([0, 1], expr.evaluate({'numbers': range(5)}))
+
+    def test_slice_with_vars(self):
+        expr = Expression("numbers[start:end]")
+        self.assertEqual([0, 1], expr.evaluate({'numbers': range(5), 'start': 0,
+                                                'end': 2}))
+
+    def test_slice_copy(self):
+        expr = Expression("numbers[:]")
+        self.assertEqual([0, 1, 2, 3, 4], expr.evaluate({'numbers': range(5)}))
+
+    def test_slice_stride(self):
+        expr = Expression("numbers[::stride]")
+        self.assertEqual([0, 2, 4], expr.evaluate({'numbers': range(5),
+                                                   'stride': 2}))
+
+    def test_slice_negative_start(self):
+        expr = Expression("numbers[-1:]")
+        self.assertEqual([4], expr.evaluate({'numbers': range(5)}))
+
+    def test_slice_negative_end(self):
+        expr = Expression("numbers[:-1]")
+        self.assertEqual([0, 1, 2, 3], expr.evaluate({'numbers': range(5)}))
+
+    def test_error_access_undefined(self):
+        expr = Expression("nothing", filename='index.html', lineno=50)
+        self.assertEqual(Undefined, type(expr.evaluate({})))
+
+    def test_error_call_undefined(self):
+        expr = Expression("nothing()", filename='index.html', lineno=50)
+        try:
+            expr.evaluate({})
+            self.fail('Expected NameError')
+        except NameError, e:
+            exc_type, exc_value, exc_traceback = sys.exc_info()
+            frame = exc_traceback.tb_next
+            frames = []
+            while frame.tb_next:
+                frame = frame.tb_next
+                frames.append(frame)
+            self.assertEqual('Variable "nothing" is not defined', str(e))
+            self.assertEqual('<Expression "nothing()">',
+                             frames[-3].tb_frame.f_code.co_name)
+            self.assertEqual('index.html',
+                             frames[-3].tb_frame.f_code.co_filename)
+            self.assertEqual(50, frames[-3].tb_lineno)
+
+    def test_error_getattr_undefined(self):
+        expr = Expression("nothing.nil", filename='index.html', lineno=50)
+        try:
+            expr.evaluate({})
+            self.fail('Expected NameError')
+        except NameError, e:
+            exc_type, exc_value, exc_traceback = sys.exc_info()
+            frame = exc_traceback.tb_next
+            frames = []
+            while frame.tb_next:
+                frame = frame.tb_next
+                frames.append(frame)
+            self.assertEqual('Variable "nothing" is not defined', str(e))
+            self.assertEqual('<Expression "nothing.nil">',
+                             frames[-3].tb_frame.f_code.co_name)
+            self.assertEqual('index.html',
+                             frames[-3].tb_frame.f_code.co_filename)
+            self.assertEqual(50, frames[-3].tb_lineno)
+
+    def test_error_getitem_undefined(self):
+        expr = Expression("nothing[0]", filename='index.html', lineno=50)
+        try:
+            expr.evaluate({})
+            self.fail('Expected NameError')
+        except NameError, e:
+            exc_type, exc_value, exc_traceback = sys.exc_info()
+            frame = exc_traceback.tb_next
+            frames = []
+            while frame.tb_next:
+                frame = frame.tb_next
+                frames.append(frame)
+            self.assertEqual('Variable "nothing" is not defined', str(e))
+            self.assertEqual('<Expression "nothing[0]">',
+                             frames[-3].tb_frame.f_code.co_name)
+            self.assertEqual('index.html',
+                             frames[-3].tb_frame.f_code.co_filename)
+            self.assertEqual(50, frames[-3].tb_lineno)
+
+    def test_error_getattr_nested_undefined(self):
+        expr = Expression("nothing.nil", filename='index.html', lineno=50)
+        val = expr.evaluate({'nothing': object()})
+        assert isinstance(val, Undefined)
+        self.assertEqual("nil", val._name)
+
+    def test_error_getitem_nested_undefined_string(self):
+        expr = Expression("nothing['bla']", filename='index.html', lineno=50)
+        val = expr.evaluate({'nothing': object()})
+        assert isinstance(val, Undefined)
+        self.assertEqual("bla", val._name)
+
+    def test_error_getitem_nested_undefined_int(self):
+        expr = Expression("nothing[0]", filename='index.html', lineno=50)
+        self.assertRaises(TypeError, expr.evaluate, {'nothing': object()})
+
+
+def suite():
+    suite = unittest.TestSuite()
+    suite.addTest(doctest.DocTestSuite(Expression.__module__))
+    suite.addTest(unittest.makeSuite(ExpressionTestCase, 'test'))
+    return suite
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')