Finally fix Python 2.6.

Also added a syntax for 2.6. There are some thing that just don't work in 2.6.

conftest.py

@@ -152,6 +152,12 @@ def works_in_py2(each_version):
     return Checker(each_version, each_version.startswith('2'))
 
 
+@pytest.fixture
+def works_ge_py27(each_version):
+    version_info = parse_version_string(each_version)
+    return Checker(each_version, version_info >= (2, 7))
+
+
 @pytest.fixture
 def works_ge_py3(each_version):
     version_info = parse_version_string(each_version)

parso/grammar.py

@@ -154,12 +154,9 @@ def load_grammar(**kwargs):
     def load_grammar(version=None):
         version_info = parse_version_string(version)
 
-        # For these versions we use the same grammar files, because nothing
-        # changed.
+        # The 3.3 grammar didn't change with the update to 3.4.
         if version_info == (3, 3):
             version_info = parse_version_string('3.4')
-        elif version_info == (2, 6):
-            version_info = parse_version_string('2.7')
 
         file = 'python/grammar%s%s.txt' % (version_info.major, version_info.minor)
 

parso/python/grammar26.txt

@@ -0,0 +1,158 @@
+# Grammar for Python
+
+# Note:  Changing the grammar specified in this file will most likely
+#        require corresponding changes in the parser module
+#        (../Modules/parsermodule.c).  If you can't make the changes to
+#        that module yourself, please co-ordinate the required changes
+#        with someone who can; ask around on python-dev for help.  Fred
+#        Drake <fdrake@acm.org> will probably be listening there.
+
+# NOTE WELL: You should also follow all the steps listed in PEP 306,
+# "How to Change Python's Grammar"
+
+# Commands for Kees Blom's railroad program
+#diagram:token NAME
+#diagram:token NUMBER
+#diagram:token STRING
+#diagram:token NEWLINE
+#diagram:token ENDMARKER
+#diagram:token INDENT
+#diagram:output\input python.bla
+#diagram:token DEDENT
+#diagram:output\textwidth 20.04cm\oddsidemargin  0.0cm\evensidemargin 0.0cm
+#diagram:rules
+
+# Start symbols for the grammar:
+#	single_input is a single interactive statement;
+#	file_input is a module or sequence of commands read from an input file;
+#	eval_input is the input for the eval() and input() functions.
+# NB: compound_stmt in single_input is followed by extra NEWLINE!
+single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
+file_input: (NEWLINE | stmt)* ENDMARKER
+eval_input: testlist NEWLINE* ENDMARKER
+
+decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+decorators: decorator+
+decorated: decorators (classdef | funcdef)
+funcdef: 'def' NAME parameters ':' suite
+parameters: '(' [varargslist] ')'
+varargslist: ((fpdef ['=' test] ',')*
+              ('*' NAME [',' '**' NAME] | '**' NAME) |
+              fpdef ['=' test] (',' fpdef ['=' test])* [','])
+fpdef: NAME | '(' fplist ')'
+fplist: fpdef (',' fpdef)* [',']
+
+stmt: simple_stmt | compound_stmt
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | exec_stmt | assert_stmt)
+expr_stmt: testlist (augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist))*)
+augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal assignments, additional restrictions enforced by the interpreter
+print_stmt: 'print' ( [ test (',' test)* [','] ] |
+                      '>>' test [ (',' test)+ [','] ] )
+del_stmt: 'del' exprlist
+pass_stmt: 'pass'
+flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
+break_stmt: 'break'
+continue_stmt: 'continue'
+return_stmt: 'return' [testlist]
+yield_stmt: yield_expr
+raise_stmt: 'raise' [test [',' test [',' test]]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+import_from: ('from' ('.'* dotted_name | '.'+)
+              'import' ('*' | '(' import_as_names ')' | import_as_names))
+import_as_name: NAME ['as' NAME]
+dotted_as_name: dotted_name ['as' NAME]
+import_as_names: import_as_name (',' import_as_name)* [',']
+dotted_as_names: dotted_as_name (',' dotted_as_name)*
+dotted_name: NAME ('.' NAME)*
+global_stmt: 'global' NAME (',' NAME)*
+exec_stmt: 'exec' expr ['in' test [',' test]]
+assert_stmt: 'assert' test [',' test]
+
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
+if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' test ':' suite ['else' ':' suite]
+for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
+try_stmt: ('try' ':' suite
+           ((except_clause ':' suite)+
+	    ['else' ':' suite]
+	    ['finally' ':' suite] |
+	   'finally' ':' suite))
+with_stmt: 'with' with_item ':' suite
+# Dave: Python2.6 actually defines a little bit of a different label called
+#       'with_var'. However in 2.7+ this is the default. Apply it for
+#       consistency reasons.
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test [('as' | ',') test]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+# Backward compatibility cruft to support:
+# [ x for x in lambda: True, lambda: False if x() ]
+# even while also allowing:
+# lambda x: 5 if x else 2
+# (But not a mix of the two)
+testlist_safe: old_test [(',' old_test)+ [',']]
+old_test: or_test | old_lambdef
+old_lambdef: 'lambda' [varargslist] ':' old_test
+
+test: or_test ['if' or_test 'else' test] | lambdef
+or_test: and_test ('or' and_test)*
+and_test: not_test ('and' not_test)*
+not_test: 'not' not_test | comparison
+comparison: expr (comp_op expr)*
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+expr: xor_expr ('|' xor_expr)*
+xor_expr: and_expr ('^' and_expr)*
+and_expr: shift_expr ('&' shift_expr)*
+shift_expr: arith_expr (('<<'|'>>') arith_expr)*
+arith_expr: term (('+'|'-') term)*
+term: factor (('*'|'/'|'%'|'//') factor)*
+factor: ('+'|'-'|'~') factor | power
+power: atom trailer* ['**' factor]
+atom: ('(' [yield_expr|testlist_comp] ')' |
+       '[' [listmaker] ']' |
+       '{' [dictorsetmaker] '}' |
+       '`' testlist1 '`' |
+       NAME | NUMBER | STRING+)
+listmaker: test ( list_for | (',' test)* [','] )
+# Dave: Renamed testlist_gexpr to testlist_comp, because in 2.7+ this is the
+#       default. It's more consistent like this.
+testlist_comp: test ( gen_for | (',' test)* [','] )
+lambdef: 'lambda' [varargslist] ':' test
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: expr (',' expr)* [',']
+testlist: test (',' test)* [',']
+# Dave: Rename from dictmaker to dictorsetmaker, because this is more
+#       consistent with the following grammars.
+dictorsetmaker: test ':' test (',' test ':' test)* [',']
+
+classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
+
+arglist: (argument ',')* (argument [',']
+                         |'*' test (',' argument)* [',' '**' test] 
+                         |'**' test)
+argument: test [gen_for] | test '=' test  # Really [keyword '='] test
+
+list_iter: list_for | list_if
+list_for: 'for' exprlist 'in' testlist_safe [list_iter]
+list_if: 'if' old_test [list_iter]
+
+gen_iter: gen_for | gen_if
+gen_for: 'for' exprlist 'in' or_test [gen_iter]
+gen_if: 'if' old_test [gen_iter]
+
+testlist1: test (',' test)*
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [testlist]

parso/python/normalizer.py

@@ -482,7 +482,6 @@ class ErrorFinder(Normalizer):
                 self._check_assignment(before_equal)
 
             augassign = node.children[1]
-            print(augassign)
             if augassign != '=' and augassign.type != 'annassign':  # Is augassign.
                 if node.children[0].type in ('testlist_star_expr', 'atom', 'testlist'):
                     message = "illegal expression for augmented assignment"

parso/python/parser.py

@@ -42,6 +42,8 @@ class Parser(BaseParser):
         # avoid extreme amounts of work around the subtle difference of 2/3
         # grammar in list comoprehensions.
         'list_for': tree.CompFor,
+        # Same here. This just exists in Python 2.6.
+        'gen_for': tree.CompFor,
         'decorator': tree.Decorator,
         'lambdef': tree.Lambda,
         'old_lambdef': tree.Lambda,

test/test_pgen2.py

@@ -166,17 +166,17 @@ def test_except_old(works_in_py2):
 
 
 # Adapted from Python 3's Lib/test/test_grammar.py:GrammarTests.testAtoms
-def test_set_literal_1(each_version):
-    _parse("""x = {'one'}""", each_version)
+def test_set_literal_1(works_ge_py27):
+    works_ge_py27.parse("""x = {'one'}""")
 
-def test_set_literal_2(each_version):
-    _parse("""x = {'one', 1,}""", each_version)
+def test_set_literal_2(works_ge_py27):
+    works_ge_py27.parse("""x = {'one', 1,}""")
 
-def test_set_literal_3(each_version):
-    _parse("""x = {'one', 'two', 'three'}""", each_version)
+def test_set_literal_3(works_ge_py27):
+    works_ge_py27.parse("""x = {'one', 'two', 'three'}""")
 
-def test_set_literal_4(each_version):
-    _parse("""x = {2, 3, 4,}""", each_version)
+def test_set_literal_4(works_ge_py27):
+    works_ge_py27.parse("""x = {2, 3, 4,}""")
 
 
 def test_new_octal_notation(each_version):

test/test_python_errors.py

@@ -58,7 +58,6 @@ FAILING_EXAMPLES = [
     'a, b += 3',
     '(a, b) += 3',
     '[a, b] += 3',
-    '[a, 1] += 3',
     # All assignment tests
     'lambda a: 1 = 1',
     '[x for x in y] = 1',
@@ -221,6 +220,10 @@ if sys.version_info >= (3,):
         # A symtable error that raises only a SyntaxWarning in Python 2.
         'def x(): from math import *',
     ]
+if sys.version_info >= (2, 7):
+    # This is something that raises a different error in 2.6 than in the other
+    # versions. Just skip it for 2.6.
+    FAILING_EXAMPLES.append('[a, 1] += 3')
 
 
 def _get_error_list(code, version=None):
@@ -306,6 +309,12 @@ def _get_actual_exception(code):
         wanted = 'SyntaxError: positional argument follows keyword argument'
     elif wanted == 'SyntaxError: assignment to keyword':
         return [wanted, "SyntaxError: can't assign to keyword"], line_nr
+    elif wanted == 'SyntaxError: assignment to None':
+        # Python 2.6 does has a slightly different error.
+        return [wanted, 'SyntaxError: cannot assign to None'], line_nr
+    elif wanted == 'SyntaxError: can not assign to __debug__':
+        # Python 2.6 does has a slightly different error.
+        return [wanted, 'SyntaxError: cannot assign to __debug__'], line_nr
     return [wanted], line_nr