1# Grammar for 2to3. This grammar supports Python 2.x and 3.x. 2 3# NOTE WELL: You should also follow all the steps listed at 4# https://devguide.python.org/grammar/ 5 6# Start symbols for the grammar: 7# file_input is a module or sequence of commands read from an input file; 8# single_input is a single interactive statement; 9# eval_input is the input for the eval() and input() functions. 10# NB: compound_stmt in single_input is followed by extra NEWLINE! 11file_input: (NEWLINE | stmt)* ENDMARKER 12single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE 13eval_input: testlist NEWLINE* ENDMARKER 14 15decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE 16decorators: decorator+ 17decorated: decorators (classdef | funcdef | async_funcdef) 18async_funcdef: ASYNC funcdef 19funcdef: 'def' NAME parameters ['->' test] ':' suite 20parameters: '(' [typedargslist] ')' 21 22# The following definition for typedarglist is equivalent to this set of rules: 23# 24# arguments = argument (',' argument)* 25# argument = tfpdef ['=' test] 26# kwargs = '**' tname [','] 27# args = '*' [tname] 28# kwonly_kwargs = (',' argument)* [',' [kwargs]] 29# args_kwonly_kwargs = args kwonly_kwargs | kwargs 30# poskeyword_args_kwonly_kwargs = arguments [',' [args_kwonly_kwargs]] 31# typedargslist_no_posonly = poskeyword_args_kwonly_kwargs | args_kwonly_kwargs 32# typedarglist = arguments ',' '/' [',' [typedargslist_no_posonly]])|(typedargslist_no_posonly)" 33# 34# It needs to be fully expanded to allow our LL(1) parser to work on it. 35 36typedargslist: tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [ 37 ',' [((tfpdef ['=' test] ',')* ('*' [tname] (',' tname ['=' test])* 38 [',' ['**' tname [',']]] | '**' tname [',']) 39 | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])] 40 ] | ((tfpdef ['=' test] ',')* ('*' [tname] (',' tname ['=' test])* 41 [',' ['**' tname [',']]] | '**' tname [',']) 42 | tfpdef ['=' test] (',' tfpdef ['=' test])* [',']) 43 44tname: NAME [':' test] 45tfpdef: tname | '(' tfplist ')' 46tfplist: tfpdef (',' tfpdef)* [','] 47 48# The following definition for varargslist is equivalent to this set of rules: 49# 50# arguments = argument (',' argument )* 51# argument = vfpdef ['=' test] 52# kwargs = '**' vname [','] 53# args = '*' [vname] 54# kwonly_kwargs = (',' argument )* [',' [kwargs]] 55# args_kwonly_kwargs = args kwonly_kwargs | kwargs 56# poskeyword_args_kwonly_kwargs = arguments [',' [args_kwonly_kwargs]] 57# vararglist_no_posonly = poskeyword_args_kwonly_kwargs | args_kwonly_kwargs 58# varargslist = arguments ',' '/' [','[(vararglist_no_posonly)]] | (vararglist_no_posonly) 59# 60# It needs to be fully expanded to allow our LL(1) parser to work on it. 61 62varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ 63 ((vfpdef ['=' test] ',')* ('*' [vname] (',' vname ['=' test])* 64 [',' ['**' vname [',']]] | '**' vname [',']) 65 | vfpdef ['=' test] (',' vfpdef ['=' test])* [',']) 66 ]] | ((vfpdef ['=' test] ',')* 67 ('*' [vname] (',' vname ['=' test])* [',' ['**' vname [',']]]| '**' vname [',']) 68 | vfpdef ['=' test] (',' vfpdef ['=' test])* [',']) 69 70vname: NAME 71vfpdef: vname | '(' vfplist ')' 72vfplist: vfpdef (',' vfpdef)* [','] 73 74stmt: simple_stmt | compound_stmt 75simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE 76small_stmt: (expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt | 77 import_stmt | global_stmt | exec_stmt | assert_stmt) 78expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) | 79 ('=' (yield_expr|testlist_star_expr))*) 80annassign: ':' test ['=' test] 81testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [','] 82augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' | 83 '<<=' | '>>=' | '**=' | '//=') 84# For normal and annotated assignments, additional restrictions enforced by the interpreter 85print_stmt: 'print' ( [ test (',' test)* [','] ] | 86 '>>' test [ (',' test)+ [','] ] ) 87del_stmt: 'del' exprlist 88pass_stmt: 'pass' 89flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt 90break_stmt: 'break' 91continue_stmt: 'continue' 92return_stmt: 'return' [testlist_star_expr] 93yield_stmt: yield_expr 94raise_stmt: 'raise' [test ['from' test | ',' test [',' test]]] 95import_stmt: import_name | import_from 96import_name: 'import' dotted_as_names 97import_from: ('from' ('.'* dotted_name | '.'+) 98 'import' ('*' | '(' import_as_names ')' | import_as_names)) 99import_as_name: NAME ['as' NAME] 100dotted_as_name: dotted_name ['as' NAME] 101import_as_names: import_as_name (',' import_as_name)* [','] 102dotted_as_names: dotted_as_name (',' dotted_as_name)* 103dotted_name: NAME ('.' NAME)* 104global_stmt: ('global' | 'nonlocal') NAME (',' NAME)* 105exec_stmt: 'exec' expr ['in' test [',' test]] 106assert_stmt: 'assert' test [',' test] 107 108compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt 109async_stmt: ASYNC (funcdef | with_stmt | for_stmt) 110if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite] 111while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite] 112for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite] 113try_stmt: ('try' ':' suite 114 ((except_clause ':' suite)+ 115 ['else' ':' suite] 116 ['finally' ':' suite] | 117 'finally' ':' suite)) 118with_stmt: 'with' with_item (',' with_item)* ':' suite 119with_item: test ['as' expr] 120with_var: 'as' expr 121# NB compile.c makes sure that the default except clause is last 122except_clause: 'except' [test [(',' | 'as') test]] 123suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT 124 125# Backward compatibility cruft to support: 126# [ x for x in lambda: True, lambda: False if x() ] 127# even while also allowing: 128# lambda x: 5 if x else 2 129# (But not a mix of the two) 130testlist_safe: old_test [(',' old_test)+ [',']] 131old_test: or_test | old_lambdef 132old_lambdef: 'lambda' [varargslist] ':' old_test 133 134namedexpr_test: test [':=' test] 135test: or_test ['if' or_test 'else' test] | lambdef 136or_test: and_test ('or' and_test)* 137and_test: not_test ('and' not_test)* 138not_test: 'not' not_test | comparison 139comparison: expr (comp_op expr)* 140comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not' 141star_expr: '*' expr 142expr: xor_expr ('|' xor_expr)* 143xor_expr: and_expr ('^' and_expr)* 144and_expr: shift_expr ('&' shift_expr)* 145shift_expr: arith_expr (('<<'|'>>') arith_expr)* 146arith_expr: term (('+'|'-') term)* 147term: factor (('*'|'@'|'/'|'%'|'//') factor)* 148factor: ('+'|'-'|'~') factor | power 149power: [AWAIT] atom trailer* ['**' factor] 150atom: ('(' [yield_expr|testlist_gexp] ')' | 151 '[' [listmaker] ']' | 152 '{' [dictsetmaker] '}' | 153 '`' testlist1 '`' | 154 NAME | NUMBER | STRING+ | '.' '.' '.') 155listmaker: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] ) 156testlist_gexp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] ) 157lambdef: 'lambda' [varargslist] ':' test 158trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME 159subscriptlist: subscript (',' subscript)* [','] 160subscript: test | [test] ':' [test] [sliceop] 161sliceop: ':' [test] 162exprlist: (expr|star_expr) (',' (expr|star_expr))* [','] 163testlist: test (',' test)* [','] 164dictsetmaker: ( ((test ':' test | '**' expr) 165 (comp_for | (',' (test ':' test | '**' expr))* [','])) | 166 ((test | star_expr) 167 (comp_for | (',' (test | star_expr))* [','])) ) 168 169classdef: 'class' NAME ['(' [arglist] ')'] ':' suite 170 171arglist: argument (',' argument)* [','] 172 173# "test '=' test" is really "keyword '=' test", but we have no such token. 174# These need to be in a single rule to avoid grammar that is ambiguous 175# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr, 176# we explicitly match '*' here, too, to give it proper precedence. 177# Illegal combinations and orderings are blocked in ast.c: 178# multiple (test comp_for) arguments are blocked; keyword unpackings 179# that precede iterable unpackings are blocked; etc. 180argument: ( test [comp_for] | 181 test ':=' test | 182 test '=' test | 183 '**' test | 184 '*' test ) 185 186comp_iter: comp_for | comp_if 187comp_for: [ASYNC] 'for' exprlist 'in' testlist_safe [comp_iter] 188comp_if: 'if' old_test [comp_iter] 189 190testlist1: test (',' test)* 191 192# not used in grammar, but may appear in "node" passed from Parser to Compiler 193encoding_decl: NAME 194 195yield_expr: 'yield' [yield_arg] 196yield_arg: 'from' test | testlist_star_expr 197