From df395991f6341be037a5c6df9b14d924d5ac9e95 Mon Sep 17 00:00:00 2001 From: Robert Collins Date: Wed, 12 Aug 2015 08:00:06 +1200 Subject: Issue #9232: Support trailing commas in function declarations. For example, "def f(*, a = 3,): pass" is now legal. Patch from Mark Dickinson. --- Doc/reference/compound_stmts.rst | 8 +-- Grammar/Grammar | 17 ++++--- Lib/test/test_grammar.py | 38 ++++++++++++++ Misc/NEWS | 4 ++ Python/ast.c | 23 +++++---- Python/graminit.c | 106 ++++++++++++++++++++++----------------- 6 files changed, 131 insertions(+), 65 deletions(-) diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst index 01cfd6d..00e6476 100644 --- a/Doc/reference/compound_stmts.rst +++ b/Doc/reference/compound_stmts.rst @@ -471,10 +471,10 @@ A function definition defines a user-defined function object (see section decorators: `decorator`+ decorator: "@" `dotted_name` ["(" [`parameter_list` [","]] ")"] NEWLINE dotted_name: `identifier` ("." `identifier`)* - parameter_list: (`defparameter` ",")* - : | "*" [`parameter`] ("," `defparameter`)* ["," "**" `parameter`] - : | "**" `parameter` - : | `defparameter` [","] ) + parameter_list: `defparameter` ("," `defparameter`)* ["," [`parameter_list_starargs`]] + : | `parameter_list_starargs` + parameter_list_starargs: "*" [`parameter`] ("," `defparameter`)* ["," ["**" `parameter` [","]]] + : | "**" `parameter` [","] parameter: `identifier` [":" `expression`] defparameter: `parameter` ["=" `expression`] funcname: `identifier` diff --git a/Grammar/Grammar b/Grammar/Grammar index 99fcea0..14bdecd 100644 --- a/Grammar/Grammar +++ b/Grammar/Grammar @@ -27,13 +27,18 @@ 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) +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) +varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [ + '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]] + | '**' vfpdef [',']]] + | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]] + | '**' vfpdef [','] +) vfpdef: NAME stmt: simple_stmt | compound_stmt diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py index ec3d783..8f8d71c 100644 --- a/Lib/test/test_grammar.py +++ b/Lib/test/test_grammar.py @@ -295,6 +295,10 @@ class GrammarTests(unittest.TestCase): pos2key2dict(1,2,k2=100,tokwarg1=100,tokwarg2=200) pos2key2dict(1,2,tokwarg1=100,tokwarg2=200, k2=100) + self.assertRaises(SyntaxError, eval, "def f(*): pass") + self.assertRaises(SyntaxError, eval, "def f(*,): pass") + self.assertRaises(SyntaxError, eval, "def f(*, **kwds): pass") + # keyword arguments after *arglist def f(*args, **kwargs): return args, kwargs @@ -352,6 +356,23 @@ class GrammarTests(unittest.TestCase): check_syntax_error(self, "f(*g(1=2))") check_syntax_error(self, "f(**g(1=2))") + # Check trailing commas are permitted in funcdef argument list + def f(a,): pass + def f(*args,): pass + def f(**kwds,): pass + def f(a, *args,): pass + def f(a, **kwds,): pass + def f(*args, b,): pass + def f(*, b,): pass + def f(*args, **kwds,): pass + def f(a, *args, b,): pass + def f(a, *, b,): pass + def f(a, *args, **kwds,): pass + def f(*args, b, **kwds,): pass + def f(*, b, **kwds,): pass + def f(a, *args, b, **kwds,): pass + def f(a, *, b, **kwds,): pass + def test_lambdef(self): ### lambdef: 'lambda' [varargslist] ':' test l1 = lambda : 0 @@ -370,6 +391,23 @@ class GrammarTests(unittest.TestCase): self.assertEqual(l6(1,2), 1+2+20) self.assertEqual(l6(1,2,k=10), 1+2+10) + # check that trailing commas are permitted + l10 = lambda a,: 0 + l11 = lambda *args,: 0 + l12 = lambda **kwds,: 0 + l13 = lambda a, *args,: 0 + l14 = lambda a, **kwds,: 0 + l15 = lambda *args, b,: 0 + l16 = lambda *, b,: 0 + l17 = lambda *args, **kwds,: 0 + l18 = lambda a, *args, b,: 0 + l19 = lambda a, *, b,: 0 + l20 = lambda a, *args, **kwds,: 0 + l21 = lambda *args, b, **kwds,: 0 + l22 = lambda *, b, **kwds,: 0 + l23 = lambda a, *args, b, **kwds,: 0 + l24 = lambda a, *, b, **kwds,: 0 + ### stmt: simple_stmt | compound_stmt # Tested below diff --git a/Misc/NEWS b/Misc/NEWS index 1aa6b09..c2ea6d6 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,10 @@ Release date: XXXX-XX-XX Core and Builtins ----------------- +- Issue #9232: Modify Python's grammar to allow trailing commas in the + argument list of a function declaration. For example, "def f(*, a = + 3,): pass" is now legal. Patch from Mark Dickinson. + - Issue #24667: Resize odict in all cases that the underlying dict resizes. Library diff --git a/Python/ast.c b/Python/ast.c index b572088..c1c3907 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -1260,16 +1260,20 @@ ast_for_arguments(struct compiling *c, const node *n) and varargslist (lambda definition). parameters: '(' [typedargslist] ')' - typedargslist: ((tfpdef ['=' test] ',')* - ('*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] - | '**' tfpdef) - | tfpdef ['=' test] (',' tfpdef ['=' test])* [',']) + typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [ + '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]] + | '**' tfpdef [',']]] + | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]] + | '**' tfpdef [',']) tfpdef: NAME [':' test] - varargslist: ((vfpdef ['=' test] ',')* - ('*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] - | '**' vfpdef) - | vfpdef ['=' test] (',' vfpdef ['=' test])* [',']) + varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [ + '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]] + | '**' vfpdef [',']]] + | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]] + | '**' vfpdef [','] + ) vfpdef: NAME + */ int i, j, k, nposargs = 0, nkwonlyargs = 0; int nposdefaults = 0, found_default = 0; @@ -1371,7 +1375,8 @@ ast_for_arguments(struct compiling *c, const node *n) i += 2; /* the name and the comma */ break; case STAR: - if (i+1 >= NCH(n)) { + if (i+1 >= NCH(n) || + (i+2 == NCH(n) && TYPE(CHILD(n, i+1)) == COMMA)) { ast_error(c, CHILD(n, i), "named arguments must follow bare *"); return NULL; diff --git a/Python/graminit.c b/Python/graminit.c index 8212b2a..354dc12 100644 --- a/Python/graminit.c +++ b/Python/graminit.c @@ -204,11 +204,13 @@ static arc arcs_9_6[2] = { {32, 7}, {0, 6}, }; -static arc arcs_9_7[2] = { +static arc arcs_9_7[3] = { {30, 12}, {34, 3}, + {0, 7}, }; -static arc arcs_9_8[1] = { +static arc arcs_9_8[2] = { + {32, 13}, {0, 8}, }; static arc arcs_9_9[2] = { @@ -221,35 +223,39 @@ static arc arcs_9_10[3] = { {0, 10}, }; static arc arcs_9_11[3] = { - {30, 13}, - {32, 14}, + {30, 14}, + {32, 15}, {0, 11}, }; static arc arcs_9_12[3] = { {32, 7}, - {31, 15}, + {31, 16}, {0, 12}, }; -static arc arcs_9_13[2] = { - {32, 14}, +static arc arcs_9_13[1] = { {0, 13}, }; static arc arcs_9_14[2] = { - {30, 16}, + {32, 15}, + {0, 14}, +}; +static arc arcs_9_15[3] = { + {30, 17}, {34, 3}, + {0, 15}, }; -static arc arcs_9_15[1] = { +static arc arcs_9_16[1] = { {26, 6}, }; -static arc arcs_9_16[3] = { - {32, 14}, - {31, 17}, - {0, 16}, +static arc arcs_9_17[3] = { + {32, 15}, + {31, 18}, + {0, 17}, }; -static arc arcs_9_17[1] = { - {26, 13}, +static arc arcs_9_18[1] = { + {26, 14}, }; -static state states_9[18] = { +static state states_9[19] = { {3, arcs_9_0}, {3, arcs_9_1}, {3, arcs_9_2}, @@ -257,17 +263,18 @@ static state states_9[18] = { {1, arcs_9_4}, {4, arcs_9_5}, {2, arcs_9_6}, - {2, arcs_9_7}, - {1, arcs_9_8}, + {3, arcs_9_7}, + {2, arcs_9_8}, {2, arcs_9_9}, {3, arcs_9_10}, {3, arcs_9_11}, {3, arcs_9_12}, - {2, arcs_9_13}, + {1, arcs_9_13}, {2, arcs_9_14}, - {1, arcs_9_15}, - {3, arcs_9_16}, - {1, arcs_9_17}, + {3, arcs_9_15}, + {1, arcs_9_16}, + {3, arcs_9_17}, + {1, arcs_9_18}, }; static arc arcs_10_0[1] = { {23, 1}, @@ -319,11 +326,13 @@ static arc arcs_11_6[2] = { {32, 7}, {0, 6}, }; -static arc arcs_11_7[2] = { +static arc arcs_11_7[3] = { {36, 12}, {34, 3}, + {0, 7}, }; -static arc arcs_11_8[1] = { +static arc arcs_11_8[2] = { + {32, 13}, {0, 8}, }; static arc arcs_11_9[2] = { @@ -336,35 +345,39 @@ static arc arcs_11_10[3] = { {0, 10}, }; static arc arcs_11_11[3] = { - {36, 13}, - {32, 14}, + {36, 14}, + {32, 15}, {0, 11}, }; static arc arcs_11_12[3] = { {32, 7}, - {31, 15}, + {31, 16}, {0, 12}, }; -static arc arcs_11_13[2] = { - {32, 14}, +static arc arcs_11_13[1] = { {0, 13}, }; static arc arcs_11_14[2] = { - {36, 16}, + {32, 15}, + {0, 14}, +}; +static arc arcs_11_15[3] = { + {36, 17}, {34, 3}, + {0, 15}, }; -static arc arcs_11_15[1] = { +static arc arcs_11_16[1] = { {26, 6}, }; -static arc arcs_11_16[3] = { - {32, 14}, - {31, 17}, - {0, 16}, +static arc arcs_11_17[3] = { + {32, 15}, + {31, 18}, + {0, 17}, }; -static arc arcs_11_17[1] = { - {26, 13}, +static arc arcs_11_18[1] = { + {26, 14}, }; -static state states_11[18] = { +static state states_11[19] = { {3, arcs_11_0}, {3, arcs_11_1}, {3, arcs_11_2}, @@ -372,17 +385,18 @@ static state states_11[18] = { {1, arcs_11_4}, {4, arcs_11_5}, {2, arcs_11_6}, - {2, arcs_11_7}, - {1, arcs_11_8}, + {3, arcs_11_7}, + {2, arcs_11_8}, {2, arcs_11_9}, {3, arcs_11_10}, {3, arcs_11_11}, {3, arcs_11_12}, - {2, arcs_11_13}, + {1, arcs_11_13}, {2, arcs_11_14}, - {1, arcs_11_15}, - {3, arcs_11_16}, - {1, arcs_11_17}, + {3, arcs_11_15}, + {1, arcs_11_16}, + {3, arcs_11_17}, + {1, arcs_11_18}, }; static arc arcs_12_0[1] = { {23, 1}, @@ -1879,11 +1893,11 @@ static dfa dfas[85] = { "\000\000\100\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, {264, "parameters", 0, 4, states_8, "\000\040\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, - {265, "typedargslist", 0, 18, states_9, + {265, "typedargslist", 0, 19, states_9, "\000\000\200\000\006\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, {266, "tfpdef", 0, 4, states_10, "\000\000\200\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, - {267, "varargslist", 0, 18, states_11, + {267, "varargslist", 0, 19, states_11, "\000\000\200\000\006\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, {268, "vfpdef", 0, 2, states_12, "\000\000\200\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"}, -- cgit v0.12