151 lines
6.6 KiB
Plaintext
151 lines
6.6 KiB
Plaintext
# 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
|