X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/4d03716eaea58ee38d77cf2bba0a72b7a27ec9fa..4bb7bf2bdc95a8035ccf167023a7044e5f8e5ef6:/src/blib2to3/Grammar.txt diff --git a/src/blib2to3/Grammar.txt b/src/blib2to3/Grammar.txt index 69b9af9..ac7ad76 100644 --- a/src/blib2to3/Grammar.txt +++ b/src/blib2to3/Grammar.txt @@ -24,7 +24,7 @@ parameters: '(' [typedargslist] ')' # arguments = argument (',' argument)* # argument = tfpdef ['=' test] # kwargs = '**' tname [','] -# args = '*' [tname] +# args = '*' [tname_star] # kwonly_kwargs = (',' argument)* [',' [kwargs]] # args_kwonly_kwargs = args kwonly_kwargs | kwargs # poskeyword_args_kwonly_kwargs = arguments [',' [args_kwonly_kwargs]] @@ -34,14 +34,15 @@ parameters: '(' [typedargslist] ')' # It needs to be fully expanded to allow our LL(1) parser to work on it. typedargslist: tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [ - ',' [((tfpdef ['=' test] ',')* ('*' [tname] (',' tname ['=' test])* + ',' [((tfpdef ['=' test] ',')* ('*' [tname_star] (',' tname ['=' test])* [',' ['**' tname [',']]] | '**' tname [',']) | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])] - ] | ((tfpdef ['=' test] ',')* ('*' [tname] (',' tname ['=' test])* + ] | ((tfpdef ['=' test] ',')* ('*' [tname_star] (',' tname ['=' test])* [',' ['**' tname [',']]] | '**' tname [',']) | tfpdef ['=' test] (',' tfpdef ['=' test])* [',']) tname: NAME [':' test] +tname_star: NAME [':' (test|star_expr)] tfpdef: tname | '(' tfplist ')' tfplist: tfpdef (',' tfpdef)* [','] @@ -105,21 +106,20 @@ global_stmt: ('global' | 'nonlocal') 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 | async_stmt +compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt | match_stmt async_stmt: ASYNC (funcdef | with_stmt | for_stmt) if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite] while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite] -for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite] +for_stmt: 'for' exprlist 'in' testlist_star_expr ':' 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] -with_var: 'as' expr +with_stmt: 'with' asexpr_test (',' asexpr_test)* ':' suite + # NB compile.c makes sure that the default except clause is last -except_clause: 'except' [test [(',' | 'as') test]] +except_clause: 'except' ['*'] [test [(',' | 'as') test]] suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT # Backward compatibility cruft to support: @@ -131,7 +131,15 @@ testlist_safe: old_test [(',' old_test)+ [',']] old_test: or_test | old_lambdef old_lambdef: 'lambda' [varargslist] ':' old_test -namedexpr_test: test [':=' test] +namedexpr_test: asexpr_test [':=' asexpr_test] + +# This is actually not a real rule, though since the parser is very +# limited in terms of the strategy about match/case rules, we are inserting +# a virtual case ( as ) as a valid expression. Unless a better +# approach is thought, the only side effect of this seem to be just allowing +# more stuff to be parser (which would fail on the ast). +asexpr_test: test ['as' test] + test: or_test ['if' or_test 'else' test] | lambdef or_test: and_test ('or' and_test)* and_test: not_test ('and' not_test)* @@ -156,15 +164,15 @@ listmaker: (namedexpr_test|star_expr) ( old_comp_for | (',' (namedexpr_test|star testlist_gexp: (namedexpr_test|star_expr) ( old_comp_for | (',' (namedexpr_test|star_expr))* [','] ) lambdef: 'lambda' [varargslist] ':' test trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME -subscriptlist: subscript (',' subscript)* [','] -subscript: test | [test] ':' [test] [sliceop] +subscriptlist: (subscript|star_expr) (',' (subscript|star_expr))* [','] +subscript: test [':=' test] | [test] ':' [test] [sliceop] sliceop: ':' [test] exprlist: (expr|star_expr) (',' (expr|star_expr))* [','] testlist: test (',' test)* [','] -dictsetmaker: ( ((test ':' test | '**' expr) - (comp_for | (',' (test ':' test | '**' expr))* [','])) | - ((test | star_expr) - (comp_for | (',' (test | star_expr))* [','])) ) +dictsetmaker: ( ((test ':' asexpr_test | '**' expr) + (comp_for | (',' (test ':' asexpr_test | '**' expr))* [','])) | + ((test [':=' test] | star_expr) + (comp_for | (',' (test [':=' test] | star_expr))* [','])) ) classdef: 'class' NAME ['(' [arglist] ')'] ':' suite @@ -179,7 +187,8 @@ arglist: argument (',' argument)* [','] # that precede iterable unpackings are blocked; etc. argument: ( test [comp_for] | test ':=' test | - test '=' test | + test 'as' test | + test '=' asexpr_test | '**' test | '*' test ) @@ -213,3 +222,31 @@ encoding_decl: NAME yield_expr: 'yield' [yield_arg] yield_arg: 'from' test | testlist_star_expr + + +# 3.10 match statement definition + +# PS: normally the grammar is much much more restricted, but +# at this moment for not trying to bother much with encoding the +# exact same DSL in a LL(1) parser, we will just accept an expression +# and let the ast.parse() step of the safe mode to reject invalid +# grammar. + +# The reason why it is more restricted is that, patterns are some +# sort of a DSL (more advanced than our LHS on assignments, but +# still in a very limited python subset). They are not really +# expressions, but who cares. If we can parse them, that is enough +# to reformat them. + +match_stmt: "match" subject_expr ':' NEWLINE INDENT case_block+ DEDENT + +# This is more permissive than the actual version. For example it +# accepts `match *something:`, even though single-item starred expressions +# are forbidden. +subject_expr: (namedexpr_test|star_expr) (',' (namedexpr_test|star_expr))* [','] + +# cases +case_block: "case" patterns [guard] ':' suite +guard: 'if' namedexpr_test +patterns: pattern (',' pattern)* [','] +pattern: (expr|star_expr) ['as' expr]