docs/grammar.rst

@@ -31,60 +31,164 @@ List of differences
 **Some of the diff have been edited to isolate the focused difference of the
 section**
+Python 3.3 is the based grammar I've started diffing with, some of the grammar
+differences marked as 3.3 are actually from older python version.
+
 Print function
 ~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/print_function.png
 Already done since the start.
+This is handle at the parser initialisation level, is activate or not the
+print_function rule.
+
 TODO
 ----
 Typed arguments
 ~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/typed_args.png
+Action:
+
+::
+
+    # parameters
+    # this is mixed with the removal of def a((b, c)): style
+    # which will probably need to continue supporting
+
+    CHANGE parameters: '(' [varargslist] ')'
+                               ^
+    TO parameters: '(' [typedargslist] ')'
+                             ^
+
+::
+
+    # CHANGE
+    varargslist: ((fpdef ['=' test] ',')*
+                  ('*' NAME [',' '**' NAME] | '**' NAME) |
+                  fpdef ['=' test] (',' fpdef ['=' test])* [','])
+    fpdef: NAME | '(' fplist ')'
+    fplist: fpdef (',' fpdef)* [',']
+
+    # TO
+    typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+            '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+          | '**' tfpdef [',']]]
+      | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [','])
+    tfpdef: NAME [':' test]
+    varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+            '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+          | '**' vfpdef [',']]]
+      | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']
+    )
+    vfpdef: NAME
+
+
+
 Function return type
 ~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/function_return_type.png
+Action:
+
+::
+
+    ADD '->' to the lexer
+    ADD ['->' test] to funcdef rule
+    funcdef: 'def' NAME parameters ['->' test] ':' suite
+
 Nonlocal statement
 ~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/nonlocal_statement.png
+Action:
+
+::
+
+    ADD 'nonlocal' to lexer
+    ADD 'nonlocal_stmt' to 'small_stmt'
+
+    ADD new rule:
+    nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+
 Exec function
 ~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/exec_function.png
+Like print_function but for 'exec'.
+
+No one seems to be using that.
+
 *var generalisation
 ~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/testlist_start_expressiong.png
+.
+
 .. image:: ./grammar_diff/star_expr.png
+.
+
 .. image:: ./grammar_diff/star_expr_in_testlist_comp.png
+.
+
 .. image:: ./grammar_diff/star_expr_in_expr_list.png
 Raise from
 ~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/raise_from.png
+Action:
+
+::
+
+    # 2.7
+    raise_stmt: 'raise' [test [',' test [',' test]]]
+
+    # 3.3
+    raise_stmt: 'raise' [test ['from' test]]
+
+    # merge
+    raise_stmt: 'raise' [test [(',' test [',' test]] | 'from' test)]
+
 Ellipsis in from import
 ~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/ellipsis_in_from_import.png
 New lambda grammar
 ~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 I have no idea on what to do with this one yet.
 .. image:: ./grammar_diff/new_lambda_grammar.png
@@ -94,6 +198,8 @@ I have no idea on what to do with this one yet.
 Remove old list comprehension syntax
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 I'm not sure on how to handle both situations (and it is needed? Old list
 comprehension syntax is like super edgy, I really wonder if anyonne has
 actually used that one that?)
@@ -105,6 +211,8 @@ actually used that one that?)
 False|True|None|... are now atoms in the grammar
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 Do I need to do anything about that?
 .. image:: ./grammar_diff/more_atoms.png
@@ -112,6 +220,8 @@ Do I need to do anything about that?
 Inheritance in class definition uses arglist now
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 I have no idea on why this is here but that's easy to change.
 .. image:: ./grammar_diff/class_inherit_is_arglist_now.png
@@ -119,6 +229,8 @@ I have no idea on why this is here but that's easy to change.
 Yield From
 ~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/yield_from.png
@@ -137,14 +249,20 @@ to support (and we already do) so we don't have to do anything.
 No more commat syntax in except close
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/no_more_commat_in_execption_close.png
 No more backquote syntax
 ~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/no_more_backquote_syntax.png
 No more '.' '.' '.' in the grammar
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Python 3.3 or earlier
+
 .. image:: ./grammar_diff/ellipsis_is_first_class_now_not_needed_anymore.png

grammar/reference_grammar_python2

@@ -87,6 +87,7 @@ old_test: or_test | old_lambdef
 old_lambdef: 'lambda' [varargslist] ':' old_test
 test: or_test ['if' or_test 'else' test] | lambdef
+lambdef: 'lambda' [varargslist] ':' test
 or_test: and_test ('or' and_test)*
 and_test: not_test ('and' not_test)*
 not_test: 'not' not_test | comparison
@@ -105,9 +106,8 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '{' [dictorsetmaker] '}' |
        '`' testlist1 '`' |
        NAME | NUMBER | STRING+)
-listmaker: test ( list_for | (',' test)* [','] )
 testlist_comp: test ( comp_for | (',' test)* [','] )
-lambdef: 'lambda' [varargslist] ':' test
+listmaker: test ( list_for | (',' test)* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
@@ -120,7 +120,7 @@ dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
 classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
 arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
+                         |'*' test (',' argument)* [',' '**' test]
                          |'**' test)
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.

grammar/reference_grammar_python3.3

+# 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"
+
+# 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() 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 ['->' test] ':' suite
+parameters: '(' [typedargslist] ')'
+typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
+       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
+     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+tfpdef: NAME [':' test]
+varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
+       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
+     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+vfpdef: NAME
+
+stmt: simple_stmt | compound_stmt
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal assignments, additional restrictions enforced by the interpreter
+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 ['from' test]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
+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)*
+nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+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 (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test ['as' NAME]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+test: or_test ['if' or_test 'else' test] | lambdef
+test_nocond: or_test | lambdef_nocond
+lambdef: 'lambda' [varargslist] ':' test
+lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
+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)*
+# <> isn't actually a valid comparison operator in Python. It's here for the
+# sake of a __future__ import described in PEP 401
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+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] ')' |
+       '[' [testlist_comp] ']' |
+       '{' [dictorsetmaker] '}' |
+       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
+testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
+                  (test (comp_for | (',' test)* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: (argument ',')* (argument [',']
+                         |'*' test (',' argument)* [',' '**' test] 
+                         |'**' test)
+# The reason that keywords are test nodes instead of NAME is that using NAME
+# results in an ambiguity. ast.c makes sure it's a NAME.
+argument: test [comp_for] | test '=' test  # Really [keyword '='] test
+comp_iter: comp_for | comp_if
+comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_if: 'if' test_nocond [comp_iter]
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist

grammar/reference_grammar_python3.4

+# 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 at
+# https://docs.python.org/devguide/grammar.html
+
+# 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() 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 ['->' test] ':' suite
+parameters: '(' [typedargslist] ')'
+typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
+       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
+     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+tfpdef: NAME [':' test]
+varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
+       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
+     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+vfpdef: NAME
+
+stmt: simple_stmt | compound_stmt
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal assignments, additional restrictions enforced by the interpreter
+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 ['from' test]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
+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)*
+nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+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 (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test ['as' NAME]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+test: or_test ['if' or_test 'else' test] | lambdef
+test_nocond: or_test | lambdef_nocond
+lambdef: 'lambda' [varargslist] ':' test
+lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
+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)*
+# <> isn't actually a valid comparison operator in Python. It's here for the
+# sake of a __future__ import described in PEP 401
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+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] ')' |
+       '[' [testlist_comp] ']' |
+       '{' [dictorsetmaker] '}' |
+       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
+testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
+                  (test (comp_for | (',' test)* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: (argument ',')* (argument [',']
+                         |'*' test (',' argument)* [',' '**' test] 
+                         |'**' test)
+# The reason that keywords are test nodes instead of NAME is that using NAME
+# results in an ambiguity. ast.c makes sure it's a NAME.
+argument: test [comp_for] | test '=' test  # Really [keyword '='] test
+comp_iter: comp_for | comp_if
+comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_if: 'if' test_nocond [comp_iter]
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist

grammar/reference_grammar_python3.5

+# 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 at
+# https://docs.python.org/devguide/grammar.html
+
+# 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() 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 | async_funcdef)
+
+async_funcdef: ASYNC funcdef
+funcdef: 'def' NAME parameters ['->' test] ':' suite
+
+parameters: '(' [typedargslist] ')'
+typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
+       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
+     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+tfpdef: NAME [':' test]
+varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
+       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
+     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+vfpdef: NAME
+
+stmt: simple_stmt | compound_stmt
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal assignments, additional restrictions enforced by the interpreter
+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 ['from' test]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
+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)*
+nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+assert_stmt: 'assert' test [',' test]
+
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: ASYNC (funcdef | with_stmt | for_stmt)
+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 (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test ['as' NAME]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+test: or_test ['if' or_test 'else' test] | lambdef
+test_nocond: or_test | lambdef_nocond
+lambdef: 'lambda' [varargslist] ':' test
+lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
+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)*
+# <> isn't actually a valid comparison operator in Python. It's here for the
+# sake of a __future__ import described in PEP 401 (which really works :-)
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+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_expr ['**' factor]
+atom_expr: [AWAIT] atom trailer*
+atom: ('(' [yield_expr|testlist_comp] ')' |
+       '[' [testlist_comp] ']' |
+       '{' [dictorsetmaker] '}' |
+       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
+testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictorsetmaker: ( ((test ':' test | '**' expr)
+                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                  ((test | star_expr)
+                   (comp_for | (',' (test | star_expr))* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: argument (',' argument)*  [',']
+
+# The reason that keywords are test nodes instead of NAME is that using NAME
+# results in an ambiguity. ast.c makes sure it's a NAME.
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test '=' test |
+            '**' test |
+            '*' test )
+
+comp_iter: comp_for | comp_if
+comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_if: 'if' test_nocond [comp_iter]
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist