diff options
Diffstat (limited to 'Lib/lib2to3/Grammar.txt')
| -rw-r--r-- | Lib/lib2to3/Grammar.txt | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/Lib/lib2to3/Grammar.txt b/Lib/lib2to3/Grammar.txt index dcdd02d..2f02e6f 100644 --- a/Lib/lib2to3/Grammar.txt +++ b/Lib/lib2to3/Grammar.txt @@ -139,15 +139,26 @@ subscript: test | [test] ':' [test] [sliceop] sliceop: ':' [test] exprlist: (expr|star_expr) (',' (expr|star_expr))* [','] testlist: test (',' test)* [','] -dictsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) | - (test (comp_for | (',' test)* [','])) ) +dictsetmaker: ( ((test ':' test | '**' expr) + (comp_for | (',' (test ':' test | '**' expr))* [','])) | + ((test | star_expr) + (comp_for | (',' (test | star_expr))* [','])) ) classdef: 'class' NAME ['(' [arglist] ')'] ':' suite -arglist: (argument ',')* (argument [','] - |'*' test (',' argument)* [',' '**' test] - |'**' test) -argument: test [comp_for] | test '=' test # Really [keyword '='] test +arglist: argument (',' argument)* [','] + +# "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) arguements are blocked; keyword unpackings +# that precede iterable unpackings are blocked; etc. +argument: ( test [comp_for] | + test '=' test | + '**' expr | + star_expr ) comp_iter: comp_for | comp_if comp_for: [ASYNC] 'for' exprlist 'in' testlist_safe [comp_iter] |