djavu-asus/emacs/elpy/rpc-venv/lib/python3.11/site-packages/blib2to3/Grammar.txt

   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!
  11 file_input: (NEWLINE | stmt)* ENDMARKER
  12 single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
  13 eval_input: testlist NEWLINE* ENDMARKER
  14
  15 typevar: NAME [':' expr]
  16 paramspec: '**' NAME
  17 typevartuple: '*' NAME
  18 typeparam: typevar | paramspec | typevartuple
  19 typeparams: '[' typeparam (',' typeparam)* [','] ']'
  20
  21 decorator: '@' namedexpr_test NEWLINE
  22 decorators: decorator+
  23 decorated: decorators (classdef | funcdef | async_funcdef)
  24 async_funcdef: ASYNC funcdef
  25 funcdef: 'def' NAME [typeparams] parameters ['->' test] ':' suite
  26 parameters: '(' [typedargslist] ')'
  27
  28 # The following definition for typedarglist is equivalent to this set of rules:
  29 #
  30 #     arguments = argument (',' argument)*
  31 #     argument = tfpdef ['=' test]
  32 #     kwargs = '**' tname [',']
  33 #     args = '*' [tname_star]
  34 #     kwonly_kwargs = (',' argument)* [',' [kwargs]]
  35 #     args_kwonly_kwargs = args kwonly_kwargs | kwargs
  36 #     poskeyword_args_kwonly_kwargs = arguments [',' [args_kwonly_kwargs]]
  37 #     typedargslist_no_posonly  = poskeyword_args_kwonly_kwargs | args_kwonly_kwargs
  38 #     typedarglist = arguments ',' '/' [',' [typedargslist_no_posonly]])|(typedargslist_no_posonly)"
  39 #
  40 # It needs to be fully expanded to allow our LL(1) parser to work on it.
  41
  42 typedargslist: tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [
  43                      ',' [((tfpdef ['=' test] ',')* ('*' [tname_star] (',' tname ['=' test])*
  44                             [',' ['**' tname [',']]] | '**' tname [','])
  45                      | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])]
  46                 ] | ((tfpdef ['=' test] ',')* ('*' [tname_star] (',' tname ['=' test])*
  47                      [',' ['**' tname [',']]] | '**' tname [','])
  48                      | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
  49
  50 tname: NAME [':' test]
  51 tname_star: NAME [':' (test|star_expr)]
  52 tfpdef: tname | '(' tfplist ')'
  53 tfplist: tfpdef (',' tfpdef)* [',']
  54
  55 # The following definition for varargslist is equivalent to this set of rules:
  56 #
  57 #     arguments = argument (',' argument )*
  58 #     argument = vfpdef ['=' test]
  59 #     kwargs = '**' vname [',']
  60 #     args = '*' [vname]
  61 #     kwonly_kwargs = (',' argument )* [',' [kwargs]]
  62 #     args_kwonly_kwargs = args kwonly_kwargs | kwargs
  63 #     poskeyword_args_kwonly_kwargs = arguments [',' [args_kwonly_kwargs]]
  64 #     vararglist_no_posonly = poskeyword_args_kwonly_kwargs | args_kwonly_kwargs
  65 #     varargslist = arguments ',' '/' [','[(vararglist_no_posonly)]] | (vararglist_no_posonly)
  66 #
  67 # It needs to be fully expanded to allow our LL(1) parser to work on it.
  68
  69 varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [
  70                      ((vfpdef ['=' test] ',')* ('*' [vname] (',' vname ['=' test])*
  71                             [',' ['**' vname [',']]] | '**' vname [','])
  72                             | vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
  73                      ]] | ((vfpdef ['=' test] ',')*
  74                      ('*' [vname] (',' vname ['=' test])*  [',' ['**' vname [',']]]| '**' vname [','])
  75                      | vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
  76
  77 vname: NAME
  78 vfpdef: vname | '(' vfplist ')'
  79 vfplist: vfpdef (',' vfpdef)* [',']
  80
  81 stmt: simple_stmt | compound_stmt
  82 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
  83 small_stmt: (type_stmt | expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
  84              import_stmt | global_stmt | exec_stmt | assert_stmt)
  85 expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
  86                      ('=' (yield_expr|testlist_star_expr))*)
  87 annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
  88 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
  89 augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
  90             '<<=' | '>>=' | '**=' | '//=')
  91 # For normal and annotated assignments, additional restrictions enforced by the interpreter
  92 print_stmt: 'print' ( [ test (',' test)* [','] ] |
  93                       '>>' test [ (',' test)+ [','] ] )
  94 del_stmt: 'del' exprlist
  95 pass_stmt: 'pass'
  96 flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
  97 break_stmt: 'break'
  98 continue_stmt: 'continue'
  99 return_stmt: 'return' [testlist_star_expr]
 100 yield_stmt: yield_expr
 101 raise_stmt: 'raise' [test ['from' test | ',' test [',' test]]]
 102 import_stmt: import_name | import_from
 103 import_name: 'import' dotted_as_names
 104 import_from: ('from' ('.'* dotted_name | '.'+)
 105               'import' ('*' | '(' import_as_names ')' | import_as_names))
 106 import_as_name: NAME ['as' NAME]
 107 dotted_as_name: dotted_name ['as' NAME]
 108 import_as_names: import_as_name (',' import_as_name)* [',']
 109 dotted_as_names: dotted_as_name (',' dotted_as_name)*
 110 dotted_name: NAME ('.' NAME)*
 111 global_stmt: ('global' | 'nonlocal') NAME (',' NAME)*
 112 exec_stmt: 'exec' expr ['in' test [',' test]]
 113 assert_stmt: 'assert' test [',' test]
 114 type_stmt: "type" NAME [typeparams] '=' expr
 115
 116 compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt | match_stmt
 117 async_stmt: ASYNC (funcdef | with_stmt | for_stmt)
 118 if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
 119 while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
 120 for_stmt: 'for' exprlist 'in' testlist_star_expr ':' suite ['else' ':' suite]
 121 try_stmt: ('try' ':' suite
 122            ((except_clause ':' suite)+
 123             ['else' ':' suite]
 124             ['finally' ':' suite] |
 125            'finally' ':' suite))
 126 with_stmt: 'with' asexpr_test (',' asexpr_test)*  ':' suite
 127
 128 # NB compile.c makes sure that the default except clause is last
 129 except_clause: 'except' ['*'] [test [(',' | 'as') test]]
 130 suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
 131
 132 # Backward compatibility cruft to support:
 133 # [ x for x in lambda: True, lambda: False if x() ]
 134 # even while also allowing:
 135 # lambda x: 5 if x else 2
 136 # (But not a mix of the two)
 137 testlist_safe: old_test [(',' old_test)+ [',']]
 138 old_test: or_test | old_lambdef
 139 old_lambdef: 'lambda' [varargslist] ':' old_test
 140
 141 namedexpr_test: asexpr_test [':=' asexpr_test]
 142
 143 # This is actually not a real rule, though since the parser is very
 144 # limited in terms of the strategy about match/case rules, we are inserting
 145 # a virtual case (<expr> as <expr>) as a valid expression. Unless a better
 146 # approach is thought, the only side effect of this seem to be just allowing
 147 # more stuff to be parser (which would fail on the ast).
 148 asexpr_test: test ['as' test]
 149
 150 test: or_test ['if' or_test 'else' test] | lambdef
 151 or_test: and_test ('or' and_test)*
 152 and_test: not_test ('and' not_test)*
 153 not_test: 'not' not_test | comparison
 154 comparison: expr (comp_op expr)*
 155 comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
 156 star_expr: '*' expr
 157 expr: xor_expr ('|' xor_expr)*
 158 xor_expr: and_expr ('^' and_expr)*
 159 and_expr: shift_expr ('&' shift_expr)*
 160 shift_expr: arith_expr (('<<'|'>>') arith_expr)*
 161 arith_expr: term (('+'|'-') term)*
 162 term: factor (('*'|'@'|'/'|'%'|'//') factor)*
 163 factor: ('+'|'-'|'~') factor | power
 164 power: [AWAIT] atom trailer* ['**' factor]
 165 atom: ('(' [yield_expr|testlist_gexp] ')' |
 166        '[' [listmaker] ']' |
 167        '{' [dictsetmaker] '}' |
 168        '`' testlist1 '`' |
 169        NAME | NUMBER | STRING+ | '.' '.' '.')
 170 listmaker: (namedexpr_test|star_expr) ( old_comp_for | (',' (namedexpr_test|star_expr))* [','] )
 171 testlist_gexp: (namedexpr_test|star_expr) ( old_comp_for | (',' (namedexpr_test|star_expr))* [','] )
 172 lambdef: 'lambda' [varargslist] ':' test
 173 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 174 subscriptlist: (subscript|star_expr) (',' (subscript|star_expr))* [',']
 175 subscript: test [':=' test] | [test] ':' [test] [sliceop]
 176 sliceop: ':' [test]
 177 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 178 testlist: test (',' test)* [',']
 179 dictsetmaker: ( ((test ':' asexpr_test | '**' expr)
 180                  (comp_for | (',' (test ':' asexpr_test | '**' expr))* [','])) |
 181                 ((test [':=' test] | star_expr)
 182                  (comp_for | (',' (test [':=' test] | star_expr))* [','])) )
 183
 184 classdef: 'class' NAME [typeparams] ['(' [arglist] ')'] ':' suite
 185
 186 arglist: argument (',' argument)* [',']
 187
 188 # "test '=' test" is really "keyword '=' test", but we have no such token.
 189 # These need to be in a single rule to avoid grammar that is ambiguous
 190 # to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
 191 # we explicitly match '*' here, too, to give it proper precedence.
 192 # Illegal combinations and orderings are blocked in ast.c:
 193 # multiple (test comp_for) arguments are blocked; keyword unpackings
 194 # that precede iterable unpackings are blocked; etc.
 195 argument: ( test [comp_for] |
 196             test ':=' test [comp_for] |
 197             test 'as' test |
 198             test '=' asexpr_test |
 199             '**' test |
 200             '*' test )
 201
 202 comp_iter: comp_for | comp_if
 203 comp_for: [ASYNC] 'for' exprlist 'in' or_test [comp_iter]
 204 comp_if: 'if' old_test [comp_iter]
 205
 206 # As noted above, testlist_safe extends the syntax allowed in list
 207 # comprehensions and generators. We can't use it indiscriminately in all
 208 # derivations using a comp_for-like pattern because the testlist_safe derivation
 209 # contains comma which clashes with trailing comma in arglist.
 210 #
 211 # This was an issue because the parser would not follow the correct derivation
 212 # when parsing syntactically valid Python code. Since testlist_safe was created
 213 # specifically to handle list comprehensions and generator expressions enclosed
 214 # with parentheses, it's safe to only use it in those. That avoids the issue; we
 215 # can parse code like set(x for x in [],).
 216 #
 217 # The syntax supported by this set of rules is not a valid Python 3 syntax,
 218 # hence the prefix "old".
 219 #
 220 # See https://bugs.python.org/issue27494
 221 old_comp_iter: old_comp_for | old_comp_if
 222 old_comp_for: [ASYNC] 'for' exprlist 'in' testlist_safe [old_comp_iter]
 223 old_comp_if: 'if' old_test [old_comp_iter]
 224
 225 testlist1: test (',' test)*
 226
 227 # not used in grammar, but may appear in "node" passed from Parser to Compiler
 228 encoding_decl: NAME
 229
 230 yield_expr: 'yield' [yield_arg]
 231 yield_arg: 'from' test | testlist_star_expr
 232
 233
 234 # 3.10 match statement definition
 235
 236 # PS: normally the grammar is much much more restricted, but
 237 # at this moment for not trying to bother much with encoding the
 238 # exact same DSL in a LL(1) parser, we will just accept an expression
 239 # and let the ast.parse() step of the safe mode to reject invalid
 240 # grammar.
 241
 242 # The reason why it is more restricted is that, patterns are some
 243 # sort of a DSL (more advanced than our LHS on assignments, but
 244 # still in a very limited python subset). They are not really
 245 # expressions, but who cares. If we can parse them, that is enough
 246 # to reformat them.
 247
 248 match_stmt: "match" subject_expr ':' NEWLINE INDENT case_block+ DEDENT
 249
 250 # This is more permissive than the actual version. For example it
 251 # accepts `match *something:`, even though single-item starred expressions
 252 # are forbidden.
 253 subject_expr: (namedexpr_test|star_expr) (',' (namedexpr_test|star_expr))* [',']
 254
 255 # cases
 256 case_block: "case" patterns [guard] ':' suite
 257 guard: 'if' namedexpr_test
 258 patterns: pattern (',' pattern)* [',']
 259 pattern: (expr|star_expr) ['as' expr]