Very subtle syntax change: in a list comprehension, the testlist in

"for <var> in <testlist> may no longer be a single test followed by
a comma.  This solves SF bug #431886.  Note that if the testlist
contains more than one test, a trailing comma is still allowed, for
maximum backward compatibility; but this example is not:

    [(x, y) for x in range(10), for y in range(10)]
                              ^

The fix involved creating a new nonterminal 'testlist_safe' whose
definition doesn't allow the trailing comma if there's only one test:

    testlist_safe: test [(',' test)+ [',']]
This commit is contained in:
Guido van Rossum 2001-10-15 15:44:05 +00:00
parent 69c0ff3836
commit 1c917072ca
5 changed files with 180 additions and 141 deletions

View File

@ -89,6 +89,7 @@ subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
sliceop: ':' [test]
exprlist: expr (',' expr)* [',']
testlist: test (',' test)* [',']
testlist_safe: test [(',' test)+ [',']]
dictmaker: test ':' test (',' test ':' test)* [',']
classdef: 'class' NAME ['(' testlist ')'] ':' suite
@ -97,5 +98,5 @@ arglist: (argument ',')* (argument [',']| '*' test [',' '**' test] | '**' test)
argument: [test '='] test # Really [keyword '='] test
list_iter: list_for | list_if
list_for: 'for' exprlist 'in' testlist [list_iter]
list_for: 'for' exprlist 'in' testlist_safe [list_iter]
list_if: 'if' test [list_iter]

View File

@ -56,10 +56,11 @@
#define sliceop 311
#define exprlist 312
#define testlist 313
#define dictmaker 314
#define classdef 315
#define arglist 316
#define argument 317
#define list_iter 318
#define list_for 319
#define list_if 320
#define testlist_safe 314
#define dictmaker 315
#define classdef 316
#define arglist 317
#define argument 318
#define list_iter 319
#define list_for 320
#define list_if 321

View File

@ -1039,6 +1039,14 @@ validate_testlist(node *tree)
}
static int
validate_testlist_safe(node *tree)
{
return (validate_repeating_list(tree, testlist_safe,
validate_test, "testlist_safe"));
}
/* '*' NAME [',' '**' NAME] | '**' NAME
*/
static int
@ -1218,7 +1226,7 @@ validate_list_for(node *tree)
res = (validate_name(CHILD(tree, 0), "for")
&& validate_exprlist(CHILD(tree, 1))
&& validate_name(CHILD(tree, 2), "in")
&& validate_testlist(CHILD(tree, 3)));
&& validate_testlist_safe(CHILD(tree, 3)));
return res;
}

View File

@ -3710,6 +3710,7 @@ com_node(struct compiling *c, node *n)
/* Expression nodes */
case testlist:
case testlist_safe:
com_list(c, n, 0);
break;
case test:

View File

@ -1255,8 +1255,9 @@ static state states_57[3] = {
static arc arcs_58_0[1] = {
{21, 1},
};
static arc arcs_58_1[1] = {
{14, 2},
static arc arcs_58_1[2] = {
{22, 2},
{0, 1},
};
static arc arcs_58_2[1] = {
{21, 3},
@ -1266,173 +1267,197 @@ static arc arcs_58_3[2] = {
{0, 3},
};
static arc arcs_58_4[2] = {
{21, 1},
{21, 3},
{0, 4},
};
static state states_58[5] = {
{1, arcs_58_0},
{1, arcs_58_1},
{2, arcs_58_1},
{1, arcs_58_2},
{2, arcs_58_3},
{2, arcs_58_4},
};
static arc arcs_59_0[1] = {
{142, 1},
{21, 1},
};
static arc arcs_59_1[1] = {
{14, 2},
};
static arc arcs_59_2[1] = {
{21, 3},
};
static arc arcs_59_3[2] = {
{22, 4},
{0, 3},
};
static arc arcs_59_4[2] = {
{21, 1},
{0, 4},
};
static state states_59[5] = {
{1, arcs_59_0},
{1, arcs_59_1},
{1, arcs_59_2},
{2, arcs_59_3},
{2, arcs_59_4},
};
static arc arcs_60_0[1] = {
{143, 1},
};
static arc arcs_60_1[1] = {
{12, 2},
};
static arc arcs_59_2[2] = {
static arc arcs_60_2[2] = {
{16, 3},
{14, 4},
};
static arc arcs_59_3[1] = {
static arc arcs_60_3[1] = {
{9, 5},
};
static arc arcs_59_4[1] = {
static arc arcs_60_4[1] = {
{15, 6},
};
static arc arcs_59_5[1] = {
static arc arcs_60_5[1] = {
{18, 7},
};
static arc arcs_59_6[1] = {
{0, 6},
};
static arc arcs_59_7[1] = {
{14, 4},
};
static state states_59[8] = {
{1, arcs_59_0},
{1, arcs_59_1},
{2, arcs_59_2},
{1, arcs_59_3},
{1, arcs_59_4},
{1, arcs_59_5},
{1, arcs_59_6},
{1, arcs_59_7},
};
static arc arcs_60_0[3] = {
{143, 1},
{23, 2},
{24, 3},
};
static arc arcs_60_1[2] = {
{22, 4},
{0, 1},
};
static arc arcs_60_2[1] = {
{21, 5},
};
static arc arcs_60_3[1] = {
{21, 6},
};
static arc arcs_60_4[4] = {
{143, 1},
{23, 2},
{24, 3},
{0, 4},
};
static arc arcs_60_5[2] = {
{22, 7},
{0, 5},
};
static arc arcs_60_6[1] = {
{0, 6},
};
static arc arcs_60_7[1] = {
{24, 3},
{14, 4},
};
static state states_60[8] = {
{3, arcs_60_0},
{2, arcs_60_1},
{1, arcs_60_2},
{1, arcs_60_0},
{1, arcs_60_1},
{2, arcs_60_2},
{1, arcs_60_3},
{4, arcs_60_4},
{2, arcs_60_5},
{1, arcs_60_4},
{1, arcs_60_5},
{1, arcs_60_6},
{1, arcs_60_7},
};
static arc arcs_61_0[1] = {
{21, 1},
static arc arcs_61_0[3] = {
{144, 1},
{23, 2},
{24, 3},
};
static arc arcs_61_1[2] = {
{20, 2},
{22, 4},
{0, 1},
};
static arc arcs_61_2[1] = {
{21, 3},
{21, 5},
};
static arc arcs_61_3[1] = {
{0, 3},
{21, 6},
};
static state states_61[4] = {
{1, arcs_61_0},
static arc arcs_61_4[4] = {
{144, 1},
{23, 2},
{24, 3},
{0, 4},
};
static arc arcs_61_5[2] = {
{22, 7},
{0, 5},
};
static arc arcs_61_6[1] = {
{0, 6},
};
static arc arcs_61_7[1] = {
{24, 3},
};
static state states_61[8] = {
{3, arcs_61_0},
{2, arcs_61_1},
{1, arcs_61_2},
{1, arcs_61_3},
{4, arcs_61_4},
{2, arcs_61_5},
{1, arcs_61_6},
{1, arcs_61_7},
};
static arc arcs_62_0[2] = {
{136, 1},
{145, 1},
static arc arcs_62_0[1] = {
{21, 1},
};
static arc arcs_62_1[1] = {
static arc arcs_62_1[2] = {
{20, 2},
{0, 1},
};
static state states_62[2] = {
{2, arcs_62_0},
{1, arcs_62_1},
static arc arcs_62_2[1] = {
{21, 3},
};
static arc arcs_63_0[1] = {
{85, 1},
};
static arc arcs_63_1[1] = {
{53, 2},
};
static arc arcs_63_2[1] = {
{74, 3},
};
static arc arcs_63_3[1] = {
{9, 4},
};
static arc arcs_63_4[2] = {
{144, 5},
{0, 4},
};
static arc arcs_63_5[1] = {
{0, 5},
};
static state states_63[6] = {
{1, arcs_63_0},
{1, arcs_63_1},
{1, arcs_63_2},
{1, arcs_63_3},
{2, arcs_63_4},
{1, arcs_63_5},
};
static arc arcs_64_0[1] = {
{81, 1},
};
static arc arcs_64_1[1] = {
{21, 2},
};
static arc arcs_64_2[2] = {
{144, 3},
{0, 2},
};
static arc arcs_64_3[1] = {
static arc arcs_62_3[1] = {
{0, 3},
};
static state states_64[4] = {
static state states_62[4] = {
{1, arcs_62_0},
{2, arcs_62_1},
{1, arcs_62_2},
{1, arcs_62_3},
};
static arc arcs_63_0[2] = {
{136, 1},
{146, 1},
};
static arc arcs_63_1[1] = {
{0, 1},
};
static state states_63[2] = {
{2, arcs_63_0},
{1, arcs_63_1},
};
static arc arcs_64_0[1] = {
{85, 1},
};
static arc arcs_64_1[1] = {
{53, 2},
};
static arc arcs_64_2[1] = {
{74, 3},
};
static arc arcs_64_3[1] = {
{142, 4},
};
static arc arcs_64_4[2] = {
{145, 5},
{0, 4},
};
static arc arcs_64_5[1] = {
{0, 5},
};
static state states_64[6] = {
{1, arcs_64_0},
{1, arcs_64_1},
{2, arcs_64_2},
{1, arcs_64_2},
{1, arcs_64_3},
{2, arcs_64_4},
{1, arcs_64_5},
};
static dfa dfas[65] = {
static arc arcs_65_0[1] = {
{81, 1},
};
static arc arcs_65_1[1] = {
{21, 2},
};
static arc arcs_65_2[2] = {
{145, 3},
{0, 2},
};
static arc arcs_65_3[1] = {
{0, 3},
};
static state states_65[4] = {
{1, arcs_65_0},
{1, arcs_65_1},
{2, arcs_65_2},
{1, arcs_65_3},
};
static dfa dfas[66] = {
{256, "single_input", 0, 3, states_0,
"\004\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\102\000"},
"\004\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\202\000"},
{257, "file_input", 0, 2, states_1,
"\204\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\102\000"},
"\204\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\202\000"},
{258, "eval_input", 0, 3, states_2,
"\000\020\001\000\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{259, "funcdef", 0, 6, states_3,
@ -1446,7 +1471,7 @@ static dfa dfas[65] = {
{263, "fplist", 0, 3, states_7,
"\000\020\001\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"},
{264, "stmt", 0, 2, states_8,
"\000\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\102\000"},
"\000\030\001\000\000\000\124\360\213\011\162\000\002\000\140\210\344\202\000"},
{265, "simple_stmt", 0, 4, states_9,
"\000\020\001\000\000\000\124\360\213\011\000\000\002\000\140\210\344\002\000"},
{266, "small_stmt", 0, 2, states_10,
@ -1488,7 +1513,7 @@ static dfa dfas[65] = {
{284, "assert_stmt", 0, 5, states_28,
"\000\000\000\000\000\000\000\000\000\010\000\000\000\000\000\000\000\000\000"},
{285, "compound_stmt", 0, 2, states_29,
"\000\010\000\000\000\000\000\000\000\000\162\000\000\000\000\000\000\100\000"},
"\000\010\000\000\000\000\000\000\000\000\162\000\000\000\000\000\000\200\000"},
{286, "if_stmt", 0, 8, states_30,
"\000\000\000\000\000\000\000\000\000\000\002\000\000\000\000\000\000\000\000"},
{287, "while_stmt", 0, 8, states_31,
@ -1545,22 +1570,24 @@ static dfa dfas[65] = {
"\000\020\001\000\000\000\000\000\000\000\000\000\000\000\140\210\344\000\000"},
{313, "testlist", 0, 3, states_57,
"\000\020\001\000\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{314, "dictmaker", 0, 5, states_58,
{314, "testlist_safe", 0, 5, states_58,
"\000\020\001\000\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{315, "classdef", 0, 8, states_59,
"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\100\000"},
{316, "arglist", 0, 8, states_60,
{315, "dictmaker", 0, 5, states_59,
"\000\020\001\000\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{316, "classdef", 0, 8, states_60,
"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\200\000"},
{317, "arglist", 0, 8, states_61,
"\000\020\201\001\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{317, "argument", 0, 4, states_61,
{318, "argument", 0, 4, states_62,
"\000\020\001\000\000\000\000\000\000\000\000\000\002\000\140\210\344\002\000"},
{318, "list_iter", 0, 2, states_62,
{319, "list_iter", 0, 2, states_63,
"\000\000\000\000\000\000\000\000\000\000\042\000\000\000\000\000\000\000\000"},
{319, "list_for", 0, 6, states_63,
{320, "list_for", 0, 6, states_64,
"\000\000\000\000\000\000\000\000\000\000\040\000\000\000\000\000\000\000\000"},
{320, "list_if", 0, 4, states_64,
{321, "list_if", 0, 4, states_65,
"\000\000\000\000\000\000\000\000\000\000\002\000\000\000\000\000\000\000\000"},
};
static label labels[146] = {
static label labels[147] = {
{0, "EMPTY"},
{256, 0},
{4, 0},
@ -1641,7 +1668,7 @@ static label labels[146] = {
{287, 0},
{288, 0},
{289, 0},
{315, 0},
{316, 0},
{1, "if"},
{1, "elif"},
{1, "else"},
@ -1692,25 +1719,26 @@ static label labels[146] = {
{306, 0},
{10, 0},
{26, 0},
{314, 0},
{315, 0},
{27, 0},
{25, 0},
{2, 0},
{3, 0},
{319, 0},
{320, 0},
{1, "lambda"},
{316, 0},
{317, 0},
{309, 0},
{310, 0},
{311, 0},
{314, 0},
{1, "class"},
{317, 0},
{318, 0},
{320, 0},
{319, 0},
{321, 0},
};
grammar _PyParser_Grammar = {
65,
66,
dfas,
{146, labels},
{147, labels},
256
};