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Commit 4905e80c authored by Benjamin Peterson's avatar Benjamin Peterson
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fix an ambiguity in the grammar from the implementation of extended unpacking 

(one which was strangely "resolved" by pgen)

This also kills the unused testlist1 rule and fixes parse tree validation of
extended unpacking.
parent 10430ad7
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Showing with 1039 additions and 1005 deletions
Grammar/Grammar
View file @ 4905e80c
......@@ -37,8 +37,9 @@ 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 (augassign (yield_expr|testlist) |
('=' (yield_expr|testlist))*)
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
......@@ -86,9 +87,9 @@ 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: star_expr (comp_op star_expr)*
comparison: expr (comp_op expr)*
comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
star_expr: ['*'] expr
star_expr: '*' expr
expr: xor_expr ('|' xor_expr)*
xor_expr: and_expr ('^' and_expr)*
and_expr: shift_expr ('&' shift_expr)*
......@@ -101,12 +102,12 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
'[' [testlist_comp] ']' |
'{' [dictorsetmaker] '}' |
NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
testlist_comp: test ( comp_for | (',' test)* [','] )
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: star_expr (',' star_expr)* [',']
exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
testlist: test (',' test)* [',']
dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
(test (comp_for | (',' test)* [','])) )
......@@ -123,8 +124,6 @@ comp_iter: comp_for | comp_if
comp_for: 'for' exprlist 'in' or_test [comp_iter]
comp_if: 'if' test_nocond [comp_iter]
testlist1: test (',' test)*
# not used in grammar, but may appear in "node" passed from Parser to Compiler
encoding_decl: NAME
......
Include/graminit.h
View file @ 4905e80c
......@@ -16,68 +16,68 @@
#define simple_stmt 269
#define small_stmt 270
#define expr_stmt 271
#define augassign 272
#define del_stmt 273
#define pass_stmt 274
#define flow_stmt 275
#define break_stmt 276
#define continue_stmt 277
#define return_stmt 278
#define yield_stmt 279
#define raise_stmt 280
#define import_stmt 281
#define import_name 282
#define import_from 283
#define import_as_name 284
#define dotted_as_name 285
#define import_as_names 286
#define dotted_as_names 287
#define dotted_name 288
#define global_stmt 289
#define nonlocal_stmt 290
#define assert_stmt 291
#define compound_stmt 292
#define if_stmt 293
#define while_stmt 294
#define for_stmt 295
#define try_stmt 296
#define with_stmt 297
#define with_item 298
#define except_clause 299
#define suite 300
#define test 301
#define test_nocond 302
#define lambdef 303
#define lambdef_nocond 304
#define or_test 305
#define and_test 306
#define not_test 307
#define comparison 308
#define comp_op 309
#define star_expr 310
#define expr 311
#define xor_expr 312
#define and_expr 313
#define shift_expr 314
#define arith_expr 315
#define term 316
#define factor 317
#define power 318
#define atom 319
#define testlist_comp 320
#define trailer 321
#define subscriptlist 322
#define subscript 323
#define sliceop 324
#define exprlist 325
#define testlist 326
#define dictorsetmaker 327
#define classdef 328
#define arglist 329
#define argument 330
#define comp_iter 331
#define comp_for 332
#define comp_if 333
#define testlist1 334
#define testlist_star_expr 272
#define augassign 273
#define del_stmt 274
#define pass_stmt 275
#define flow_stmt 276
#define break_stmt 277
#define continue_stmt 278
#define return_stmt 279
#define yield_stmt 280
#define raise_stmt 281
#define import_stmt 282
#define import_name 283
#define import_from 284
#define import_as_name 285
#define dotted_as_name 286
#define import_as_names 287
#define dotted_as_names 288
#define dotted_name 289
#define global_stmt 290
#define nonlocal_stmt 291
#define assert_stmt 292
#define compound_stmt 293
#define if_stmt 294
#define while_stmt 295
#define for_stmt 296
#define try_stmt 297
#define with_stmt 298
#define with_item 299
#define except_clause 300
#define suite 301
#define test 302
#define test_nocond 303
#define lambdef 304
#define lambdef_nocond 305
#define or_test 306
#define and_test 307
#define not_test 308
#define comparison 309
#define comp_op 310
#define star_expr 311
#define expr 312
#define xor_expr 313
#define and_expr 314
#define shift_expr 315
#define arith_expr 316
#define term 317
#define factor 318
#define power 319
#define atom 320
#define testlist_comp 321
#define trailer 322
#define subscriptlist 323
#define subscript 324
#define sliceop 325
#define exprlist 326
#define testlist 327
#define dictorsetmaker 328
#define classdef 329
#define arglist 330
#define argument 331
#define comp_iter 332
#define comp_for 333
#define comp_if 334
#define encoding_decl 335
#define yield_expr 336
Lib/symbol.py
View file @ 4905e80c
......@@ -26,69 +26,69 @@ stmt = 268
simple_stmt = 269
small_stmt = 270
expr_stmt = 271
augassign = 272
del_stmt = 273
pass_stmt = 274
flow_stmt = 275
break_stmt = 276
continue_stmt = 277
return_stmt = 278
yield_stmt = 279
raise_stmt = 280
import_stmt = 281
import_name = 282
import_from = 283
import_as_name = 284
dotted_as_name = 285
import_as_names = 286
dotted_as_names = 287
dotted_name = 288
global_stmt = 289
nonlocal_stmt = 290
assert_stmt = 291
compound_stmt = 292
if_stmt = 293
while_stmt = 294
for_stmt = 295
try_stmt = 296
with_stmt = 297
with_item = 298
except_clause = 299
suite = 300
test = 301
test_nocond = 302
lambdef = 303
lambdef_nocond = 304
or_test = 305
and_test = 306
not_test = 307
comparison = 308
comp_op = 309
star_expr = 310
expr = 311
xor_expr = 312
and_expr = 313
shift_expr = 314
arith_expr = 315
term = 316
factor = 317
power = 318
atom = 319
testlist_comp = 320
trailer = 321
subscriptlist = 322
subscript = 323
sliceop = 324
exprlist = 325
testlist = 326
dictorsetmaker = 327
classdef = 328
arglist = 329
argument = 330
comp_iter = 331
comp_for = 332
comp_if = 333
testlist1 = 334
testlist_star_expr = 272
augassign = 273
del_stmt = 274
pass_stmt = 275
flow_stmt = 276
break_stmt = 277
continue_stmt = 278
return_stmt = 279
yield_stmt = 280
raise_stmt = 281
import_stmt = 282
import_name = 283
import_from = 284
import_as_name = 285
dotted_as_name = 286
import_as_names = 287
dotted_as_names = 288
dotted_name = 289
global_stmt = 290
nonlocal_stmt = 291
assert_stmt = 292
compound_stmt = 293
if_stmt = 294
while_stmt = 295
for_stmt = 296
try_stmt = 297
with_stmt = 298
with_item = 299
except_clause = 300
suite = 301
test = 302
test_nocond = 303
lambdef = 304
lambdef_nocond = 305
or_test = 306
and_test = 307
not_test = 308
comparison = 309
comp_op = 310
star_expr = 311
expr = 312
xor_expr = 313
and_expr = 314
shift_expr = 315
arith_expr = 316
term = 317
factor = 318
power = 319
atom = 320
testlist_comp = 321
trailer = 322
subscriptlist = 323
subscript = 324
sliceop = 325
exprlist = 326
testlist = 327
dictorsetmaker = 328
classdef = 329
arglist = 330
argument = 331
comp_iter = 332
comp_for = 333
comp_if = 334
encoding_decl = 335
yield_expr = 336
#--end constants--
......
Lib/test/test_parser.py
View file @ 4905e80c
......@@ -242,6 +242,12 @@ class RoundtripLegalSyntaxTestCase(unittest.TestCase):
(0, '', 2, -1)],
terminals)
def test_extended_unpacking(self):
self.check_suite("*a = y")
self.check_suite("x, *b, = m")
self.check_suite("[*a, *b] = y")
self.check_suite("for [*x, b] in x: pass")
#
# Second, we take *invalid* trees and make sure we get ParserError
......
Misc/NEWS
View file @ 4905e80c
......@@ -12,6 +12,8 @@ What's New in Python 3.2 Alpha 1?
Core and Builtins
-----------------
- Issue #5460: Fix an ambiguity in the grammar.
- Issue #1766304: Improve performance of membership tests on range objects.
- Issue #6713: Improve performance of integer -> string conversions.
......
Modules/parsermodule.c
View file @ 4905e80c
......@@ -943,7 +943,7 @@ VALIDATER(return_stmt); VALIDATER(raise_stmt);
VALIDATER(import_stmt); VALIDATER(import_stmt);
VALIDATER(import_name); VALIDATER(yield_stmt);
VALIDATER(global_stmt); VALIDATER(assert_stmt);
VALIDATER(compound_stmt);
VALIDATER(compound_stmt); VALIDATER(test_or_star_expr);
VALIDATER(while); VALIDATER(for);
VALIDATER(try); VALIDATER(except_clause);
VALIDATER(test); VALIDATER(and_test);
......@@ -958,10 +958,10 @@ VALIDATER(trailer); VALIDATER(subscript);
VALIDATER(subscriptlist); VALIDATER(sliceop);
VALIDATER(exprlist); VALIDATER(dictorsetmaker);
VALIDATER(arglist); VALIDATER(argument);
VALIDATER(testlist1); VALIDATER(comp_for);
VALIDATER(comp_for);
VALIDATER(comp_iter); VALIDATER(comp_if);
VALIDATER(testlist_comp); VALIDATER(yield_expr);
VALIDATER(yield_or_testlist); VALIDATER(or_test);
VALIDATER(or_test);
VALIDATER(test_nocond); VALIDATER(lambdef_nocond);
#undef VALIDATER
......@@ -1183,12 +1183,11 @@ validate_testlist(node *tree)
validate_test, "testlist"));
}
static int
validate_testlist1(node *tree)
validate_testlist_star_expr(node *tl)
{
return (validate_repeating_list(tree, testlist1,
validate_test, "testlist1"));
return (validate_repeating_list(tl, testlist_star_expr, validate_test_or_star_expr,
"testlist"));
}
......@@ -1516,12 +1515,17 @@ validate_compound_stmt(node *tree)
}
static int
validate_yield_or_testlist(node *tree)
validate_yield_or_testlist(node *tree, int tse)
{
if (TYPE(tree) == yield_expr)
return validate_yield_expr(tree);
else
return validate_testlist(tree);
if (TYPE(tree) == yield_expr) {
return validate_yield_expr(tree);
}
else {
if (tse)
return validate_testlist_star_expr(tree);
else
return validate_testlist(tree);
}
}
static int
......@@ -1531,12 +1535,12 @@ validate_expr_stmt(node *tree)
int nch = NCH(tree);
int res = (validate_ntype(tree, expr_stmt)
&& is_odd(nch)
&& validate_testlist(CHILD(tree, 0)));
&& validate_testlist_star_expr(CHILD(tree, 0)));
if (res && nch == 3
&& TYPE(CHILD(tree, 1)) == augassign) {
res = validate_numnodes(CHILD(tree, 1), 1, "augassign")
&& validate_yield_or_testlist(CHILD(tree, 2));
&& validate_yield_or_testlist(CHILD(tree, 2), 0);
if (res) {
char *s = STR(CHILD(CHILD(tree, 1), 0));
......@@ -1560,7 +1564,7 @@ validate_expr_stmt(node *tree)
else {
for (j = 1; res && (j < nch); j += 2)
res = validate_equal(CHILD(tree, j))
&& validate_yield_or_testlist(CHILD(tree, j + 1));
&& validate_yield_or_testlist(CHILD(tree, j + 1), 1);
}
return (res);
}
......@@ -2077,11 +2081,11 @@ validate_comparison(node *tree)
int nch = NCH(tree);
int res = (validate_ntype(tree, comparison)
&& is_odd(nch)
&& validate_star_expr(CHILD(tree, 0)));
&& validate_expr(CHILD(tree, 0)));
for (pos = 1; res && (pos < nch); pos += 2)
res = (validate_comp_op(CHILD(tree, pos))
&& validate_star_expr(CHILD(tree, pos + 1)));
&& validate_expr(CHILD(tree, pos + 1)));
return (res);
}
......@@ -2143,12 +2147,10 @@ validate_star_expr(node *tree)
{
int res = validate_ntype(tree, star_expr);
if (!res) return res;
if (NCH(tree) == 2) {
return validate_ntype(CHILD(tree, 0), STAR) && \
validate_expr(CHILD(tree, 1));
} else {
return validate_expr(CHILD(tree, 0));
}
if (!validate_numnodes(tree, 2, "star_expr"))
return 0;
return validate_ntype(CHILD(tree, 0), STAR) && \
validate_expr(CHILD(tree, 1));
}
......@@ -2379,7 +2381,7 @@ validate_testlist_comp(node *tree)
if (nch == 0)
err_string("missing child nodes of testlist_comp");
else {
ok = validate_test(CHILD(tree, 0));
ok = validate_test_or_star_expr(CHILD(tree, 0));
}
/*
......@@ -2392,7 +2394,7 @@ validate_testlist_comp(node *tree)
int i = 1;
while (ok && nch - i >= 2) {
ok = (validate_comma(CHILD(tree, i))
&& validate_test(CHILD(tree, i+1)));
&& validate_test_or_star_expr(CHILD(tree, i+1)));
i += 2;
}
if (ok && i == nch-1)
......@@ -2785,11 +2787,28 @@ validate_sliceop(node *tree)
}
static int
validate_test_or_star_expr(node *n)
{
if (TYPE(n) == test)
return validate_test(n);
return validate_star_expr(n);
}
static int
validate_expr_or_star_expr(node *n)
{
if (TYPE(n) == expr)
return validate_expr(n);
return validate_star_expr(n);
}
static int
validate_exprlist(node *tree)
{
return (validate_repeating_list(tree, exprlist,
validate_star_expr, "exprlist"));
validate_expr_or_star_expr, "exprlist"));
}
......@@ -2970,9 +2989,6 @@ validate_node(node *tree)
case yield_expr:
res = validate_yield_expr(tree);
break;
case testlist1:
res = validate_testlist1(tree);
break;
case test:
res = validate_test(tree);
break;
......
Python/ast.c
View file @ 4905e80c
......@@ -603,20 +603,23 @@ ast_for_comp_op(struct compiling *c, const node *n)
static asdl_seq *
seq_for_testlist(struct compiling *c, const node *n)
{
/* testlist: test (',' test)* [','] */
/* testlist: test (',' test)* [',']
testlist_star_expr: test|star_expr (',' test|star_expr)* [',']
*/
asdl_seq *seq;
expr_ty expression;
int i;
assert(TYPE(n) == testlist || TYPE(n) == testlist_comp);
assert(TYPE(n) == testlist || TYPE(n) == testlist_star_expr || TYPE(n) == testlist_comp);
seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!seq)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
assert(TYPE(CHILD(n, i)) == test || TYPE(CHILD(n, i)) == test_nocond);
const node *ch = CHILD(n, i);
assert(TYPE(ch) == test || TYPE(ch) == test_nocond || TYPE(ch) == star_expr);
expression = ast_for_expr(c, CHILD(n, i));
expression = ast_for_expr(c, ch);
if (!expression)
return NULL;
......@@ -1886,10 +1889,9 @@ ast_for_expr(struct compiling *c, const node *n)
break;
case star_expr:
if (TYPE(CHILD(n, 0)) == STAR) {
return ast_for_starred(c, n);
}
/* Fallthrough */
if (TYPE(CHILD(n, 0)) == STAR)
return ast_for_starred(c, n);
/* Fall through to generic case. */
/* The next five cases all handle BinOps. The main body of code
is the same in each case, but the switch turned inside out to
reuse the code for each type of operator.
......@@ -2067,7 +2069,6 @@ ast_for_testlist(struct compiling *c, const node* n)
{
/* testlist_comp: test (comp_for | (',' test)* [',']) */
/* testlist: test (',' test)* [','] */
/* testlist1: test (',' test)* */
assert(NCH(n) > 0);
if (TYPE(n) == testlist_comp) {
if (NCH(n) > 1)
......@@ -2075,7 +2076,7 @@ ast_for_testlist(struct compiling *c, const node* n)
}
else {
assert(TYPE(n) == testlist ||
TYPE(n) == testlist1);
TYPE(n) == testlist_star_expr);
}
if (NCH(n) == 1)
return ast_for_expr(c, CHILD(n, 0));
......@@ -2091,9 +2092,9 @@ static stmt_ty
ast_for_expr_stmt(struct compiling *c, const node *n)
{
REQ(n, expr_stmt);
/* expr_stmt: testlist (augassign (yield_expr|testlist)
/* expr_stmt: testlist_star_expr (augassign (yield_expr|testlist)
| ('=' (yield_expr|testlist))*)
testlist: test (',' test)* [',']
testlist_star_expr: (test|star_expr) (',' test|star_expr)* [',']
augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^='
| '<<=' | '>>=' | '**=' | '//='
test: ... here starts the operator precendence dance
......@@ -2161,7 +2162,7 @@ ast_for_expr_stmt(struct compiling *c, const node *n)
asdl_seq_SET(targets, i / 2, e);
}
value = CHILD(n, NCH(n) - 1);
if (TYPE(value) == testlist)
if (TYPE(value) == testlist_star_expr)
expression = ast_for_testlist(c, value);
else
expression = ast_for_expr(c, value);
......
Python/graminit.c
View file @ 4905e80c
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