forked from ClickHouse/ClickHouse
-
Notifications
You must be signed in to change notification settings - Fork 0
/
ExpressionElementParsers.cpp
2387 lines (1990 loc) · 68 KB
/
ExpressionElementParsers.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#include <cerrno>
#include <cstdlib>
#include <Poco/String.h>
#include <IO/ReadBufferFromMemory.h>
#include <IO/ReadHelpers.h>
#include <Common/typeid_cast.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/BinStringDecodeHelper.h>
#include <Parsers/DumpASTNode.h>
#include <Parsers/ASTAsterisk.h>
#include <Parsers/ASTCollation.h>
#include <Parsers/ASTColumnsTransformers.h>
#include <Parsers/ASTExpressionList.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTFunctionWithKeyValueArguments.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/ASTOrderByElement.h>
#include <Parsers/ASTInterpolateElement.h>
#include <Parsers/ASTQualifiedAsterisk.h>
#include <Parsers/ASTQueryParameter.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Parsers/ASTSubquery.h>
#include <Parsers/ASTTTLElement.h>
#include <Parsers/ASTWindowDefinition.h>
#include <Parsers/ASTAssignment.h>
#include <Parsers/ASTColumnsMatcher.h>
#include <Parsers/ASTExplainQuery.h>
#include <Parsers/ASTSetQuery.h>
#include <Parsers/ASTSelectQuery.h>
#include <Parsers/ASTTablesInSelectQuery.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/IAST_fwd.h>
#include <Parsers/ParserSelectWithUnionQuery.h>
#include <Parsers/ParserCase.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ParserCreateQuery.h>
#include <Parsers/ParserExplainQuery.h>
#include <Parsers/queryToString.h>
#include <Interpreters/StorageID.h>
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int SYNTAX_ERROR;
extern const int LOGICAL_ERROR;
}
/*
* Build an AST with the following structure:
*
* ```
* SelectWithUnionQuery (children 1)
* ExpressionList (children 1)
* SelectQuery (children 2)
* ExpressionList (children 1)
* Asterisk
* TablesInSelectQuery (children 1)
* TablesInSelectQueryElement (children 1)
* TableExpression (children 1)
* Function <...>
* ```
*/
static ASTPtr buildSelectFromTableFunction(const std::shared_ptr<ASTFunction> & ast_function)
{
auto result_select_query = std::make_shared<ASTSelectWithUnionQuery>();
{
auto select_ast = std::make_shared<ASTSelectQuery>();
select_ast->setExpression(ASTSelectQuery::Expression::SELECT, std::make_shared<ASTExpressionList>());
select_ast->select()->children.push_back(std::make_shared<ASTAsterisk>());
auto list_of_selects = std::make_shared<ASTExpressionList>();
list_of_selects->children.push_back(select_ast);
result_select_query->children.push_back(std::move(list_of_selects));
result_select_query->list_of_selects = result_select_query->children.back();
{
auto tables = std::make_shared<ASTTablesInSelectQuery>();
select_ast->setExpression(ASTSelectQuery::Expression::TABLES, tables);
auto tables_elem = std::make_shared<ASTTablesInSelectQueryElement>();
auto table_expr = std::make_shared<ASTTableExpression>();
tables->children.push_back(tables_elem);
tables_elem->table_expression = table_expr;
tables_elem->children.push_back(table_expr);
table_expr->table_function = ast_function;
table_expr->children.push_back(table_expr->table_function);
}
}
return result_select_query;
}
bool ParserSubquery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserSelectWithUnionQuery select;
ParserExplainQuery explain;
if (pos->type != TokenType::OpeningRoundBracket)
return false;
++pos;
ASTPtr result_node = nullptr;
if (ASTPtr select_node; select.parse(pos, select_node, expected))
{
result_node = std::move(select_node);
}
else if (ASTPtr explain_node; explain.parse(pos, explain_node, expected))
{
const auto & explain_query = explain_node->as<const ASTExplainQuery &>();
if (explain_query.getTableFunction() || explain_query.getTableOverride())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "EXPLAIN in a subquery cannot have a table function or table override");
/// Replace subquery `(EXPLAIN <kind> <explain_settings> SELECT ...)`
/// with `(SELECT * FROM viewExplain("<kind>", "<explain_settings>", SELECT ...))`
String kind_str = ASTExplainQuery::toString(explain_query.getKind());
String settings_str;
if (ASTPtr settings_ast = explain_query.getSettings())
{
if (!settings_ast->as<ASTSetQuery>())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "EXPLAIN settings must be a SET query");
settings_str = queryToString(settings_ast);
}
const ASTPtr & explained_ast = explain_query.getExplainedQuery();
if (explained_ast)
{
auto view_explain = makeASTFunction("viewExplain",
std::make_shared<ASTLiteral>(kind_str),
std::make_shared<ASTLiteral>(settings_str),
explained_ast);
result_node = buildSelectFromTableFunction(view_explain);
}
else
{
auto view_explain = makeASTFunction("viewExplain",
std::make_shared<ASTLiteral>(kind_str),
std::make_shared<ASTLiteral>(settings_str));
result_node = buildSelectFromTableFunction(view_explain);
}
}
else
{
return false;
}
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
node = std::make_shared<ASTSubquery>();
node->children.push_back(result_node);
return true;
}
bool ParserIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
/// Identifier in backquotes or in double quotes
if (pos->type == TokenType::QuotedIdentifier)
{
ReadBufferFromMemory buf(pos->begin, pos->size());
String s;
if (*pos->begin == '`')
readBackQuotedStringWithSQLStyle(s, buf);
else
readDoubleQuotedStringWithSQLStyle(s, buf);
if (s.empty()) /// Identifiers "empty string" are not allowed.
return false;
node = std::make_shared<ASTIdentifier>(s);
++pos;
return true;
}
else if (pos->type == TokenType::BareWord)
{
node = std::make_shared<ASTIdentifier>(String(pos->begin, pos->end));
++pos;
return true;
}
else if (allow_query_parameter && pos->type == TokenType::OpeningCurlyBrace)
{
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "substitution name (identifier)");
return false;
}
String name(pos->begin, pos->end);
++pos;
if (pos->type != TokenType::Colon)
{
expected.add(pos, "colon between name and type");
return false;
}
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "substitution type (identifier)");
return false;
}
String type(pos->begin, pos->end);
++pos;
if (type != "Identifier")
{
expected.add(pos, "substitution type (identifier)");
return false;
}
if (pos->type != TokenType::ClosingCurlyBrace)
{
expected.add(pos, "closing curly brace");
return false;
}
++pos;
node = std::make_shared<ASTIdentifier>("", std::make_shared<ASTQueryParameter>(name, type));
return true;
}
return false;
}
bool ParserTableAsStringLiteralIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != TokenType::StringLiteral)
return false;
ReadBufferFromMemory in(pos->begin, pos->size());
String s;
if (!tryReadQuotedStringInto(s, in))
{
expected.add(pos, "string literal");
return false;
}
if (in.count() != pos->size())
{
expected.add(pos, "string literal");
return false;
}
if (s.empty())
{
expected.add(pos, "non-empty string literal");
return false;
}
node = std::make_shared<ASTTableIdentifier>(s);
++pos;
return true;
}
bool ParserCompoundIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ASTPtr id_list;
if (!ParserList(std::make_unique<ParserIdentifier>(allow_query_parameter), std::make_unique<ParserToken>(TokenType::Dot), false)
.parse(pos, id_list, expected))
return false;
std::vector<String> parts;
ASTs params;
const auto & list = id_list->as<ASTExpressionList &>();
for (const auto & child : list.children)
{
parts.emplace_back(getIdentifierName(child));
if (parts.back().empty())
params.push_back(child->as<ASTIdentifier>()->getParam());
}
ParserKeyword s_uuid("UUID");
UUID uuid = UUIDHelpers::Nil;
if (table_name_with_optional_uuid)
{
if (parts.size() > 2)
return false;
if (s_uuid.ignore(pos, expected))
{
ParserStringLiteral uuid_p;
ASTPtr ast_uuid;
if (!uuid_p.parse(pos, ast_uuid, expected))
return false;
uuid = parseFromString<UUID>(ast_uuid->as<ASTLiteral>()->value.get<String>());
}
if (parts.size() == 1) node = std::make_shared<ASTTableIdentifier>(parts[0], std::move(params));
else node = std::make_shared<ASTTableIdentifier>(parts[0], parts[1], std::move(params));
node->as<ASTTableIdentifier>()->uuid = uuid;
}
else
node = std::make_shared<ASTIdentifier>(std::move(parts), false, std::move(params));
return true;
}
ASTPtr createFunctionCast(const ASTPtr & expr_ast, const ASTPtr & type_ast)
{
/// Convert to canonical representation in functional form: CAST(expr, 'type')
auto type_literal = std::make_shared<ASTLiteral>(queryToString(type_ast));
return makeASTFunction("CAST", expr_ast, std::move(type_literal));
}
bool ParserFilterClause::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
assert(node);
ASTFunction & function = dynamic_cast<ASTFunction &>(*node);
ParserToken parser_opening_bracket(TokenType::OpeningRoundBracket);
if (!parser_opening_bracket.ignore(pos, expected))
{
return false;
}
ParserKeyword parser_where("WHERE");
if (!parser_where.ignore(pos, expected))
{
return false;
}
ParserExpressionList parser_condition(false);
ASTPtr condition;
if (!parser_condition.parse(pos, condition, expected) || condition->children.size() != 1)
{
return false;
}
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (!parser_closing_bracket.ignore(pos, expected))
{
return false;
}
function.name += "If";
function.arguments->children.push_back(condition->children[0]);
return true;
}
bool ParserWindowReference::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
assert(node);
ASTFunction & function = dynamic_cast<ASTFunction &>(*node);
// Variant 1:
// function_name ( * ) OVER window_name
if (pos->type != TokenType::OpeningRoundBracket)
{
ASTPtr window_name_ast;
ParserIdentifier window_name_parser;
if (window_name_parser.parse(pos, window_name_ast, expected))
{
function.window_name = getIdentifierName(window_name_ast);
return true;
}
else
{
return false;
}
}
// Variant 2:
// function_name ( * ) OVER ( window_definition )
ParserWindowDefinition parser_definition;
return parser_definition.parse(pos, function.window_definition, expected);
}
static bool tryParseFrameDefinition(ASTWindowDefinition * node, IParser::Pos & pos,
Expected & expected)
{
ParserKeyword keyword_rows("ROWS");
ParserKeyword keyword_groups("GROUPS");
ParserKeyword keyword_range("RANGE");
node->frame_is_default = false;
if (keyword_rows.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::ROWS;
}
else if (keyword_groups.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::GROUPS;
}
else if (keyword_range.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::RANGE;
}
else
{
/* No frame clause. */
node->frame_is_default = true;
return true;
}
ParserKeyword keyword_between("BETWEEN");
ParserKeyword keyword_unbounded("UNBOUNDED");
ParserKeyword keyword_preceding("PRECEDING");
ParserKeyword keyword_following("FOLLOWING");
ParserKeyword keyword_and("AND");
ParserKeyword keyword_current_row("CURRENT ROW");
// There are two variants of grammar for the frame:
// 1) ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
// 2) ROWS UNBOUNDED PRECEDING
// When the frame end is not specified (2), it defaults to CURRENT ROW.
const bool has_frame_end = keyword_between.ignore(pos, expected);
if (keyword_current_row.ignore(pos, expected))
{
node->frame_begin_type = WindowFrame::BoundaryType::Current;
}
else
{
ParserExpression parser_expression;
if (keyword_unbounded.ignore(pos, expected))
{
node->frame_begin_type = WindowFrame::BoundaryType::Unbounded;
}
else if (parser_expression.parse(pos, node->frame_begin_offset, expected))
{
// We will evaluate the expression for offset expression later.
node->frame_begin_type = WindowFrame::BoundaryType::Offset;
}
else
{
return false;
}
if (keyword_preceding.ignore(pos, expected))
{
node->frame_begin_preceding = true;
}
else if (keyword_following.ignore(pos, expected))
{
node->frame_begin_preceding = false;
if (node->frame_begin_type == WindowFrame::BoundaryType::Unbounded)
{
throw Exception(ErrorCodes::BAD_ARGUMENTS,
"Frame start cannot be UNBOUNDED FOLLOWING");
}
}
else
{
return false;
}
}
if (has_frame_end)
{
if (!keyword_and.ignore(pos, expected))
{
return false;
}
if (keyword_current_row.ignore(pos, expected))
{
node->frame_end_type = WindowFrame::BoundaryType::Current;
}
else
{
ParserExpression parser_expression;
if (keyword_unbounded.ignore(pos, expected))
{
node->frame_end_type = WindowFrame::BoundaryType::Unbounded;
}
else if (parser_expression.parse(pos, node->frame_end_offset, expected))
{
// We will evaluate the expression for offset expression later.
node->frame_end_type = WindowFrame::BoundaryType::Offset;
}
else
{
return false;
}
if (keyword_preceding.ignore(pos, expected))
{
node->frame_end_preceding = true;
if (node->frame_end_type == WindowFrame::BoundaryType::Unbounded)
{
throw Exception(ErrorCodes::BAD_ARGUMENTS,
"Frame end cannot be UNBOUNDED PRECEDING");
}
}
else if (keyword_following.ignore(pos, expected))
{
// Positive offset or UNBOUNDED FOLLOWING.
node->frame_end_preceding = false;
}
else
{
return false;
}
}
}
return true;
}
// All except parent window name.
static bool parseWindowDefinitionParts(IParser::Pos & pos,
ASTWindowDefinition & node, Expected & expected)
{
ParserKeyword keyword_partition_by("PARTITION BY");
ParserNotEmptyExpressionList columns_partition_by(
false /* we don't allow declaring aliases here*/);
ParserKeyword keyword_order_by("ORDER BY");
ParserOrderByExpressionList columns_order_by;
if (keyword_partition_by.ignore(pos, expected))
{
ASTPtr partition_by_ast;
if (columns_partition_by.parse(pos, partition_by_ast, expected))
{
node.children.push_back(partition_by_ast);
node.partition_by = partition_by_ast;
}
else
{
return false;
}
}
if (keyword_order_by.ignore(pos, expected))
{
ASTPtr order_by_ast;
if (columns_order_by.parse(pos, order_by_ast, expected))
{
node.children.push_back(order_by_ast);
node.order_by = order_by_ast;
}
else
{
return false;
}
}
return tryParseFrameDefinition(&node, pos, expected);
}
bool ParserWindowDefinition::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
auto result = std::make_shared<ASTWindowDefinition>();
ParserToken parser_openging_bracket(TokenType::OpeningRoundBracket);
if (!parser_openging_bracket.ignore(pos, expected))
{
return false;
}
// We can have a parent window name specified before all other things. No
// easy way to distinguish identifier from keywords, so just try to parse it
// both ways.
if (parseWindowDefinitionParts(pos, *result, expected))
{
// Successfully parsed without parent window specifier. It can be empty,
// so check that it is followed by the closing bracket.
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (parser_closing_bracket.ignore(pos, expected))
{
node = result;
return true;
}
}
// Try to parse with parent window specifier.
ParserIdentifier parser_parent_window;
ASTPtr window_name_identifier;
if (!parser_parent_window.parse(pos, window_name_identifier, expected))
{
return false;
}
result->parent_window_name = window_name_identifier->as<const ASTIdentifier &>().name();
if (!parseWindowDefinitionParts(pos, *result, expected))
{
return false;
}
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (!parser_closing_bracket.ignore(pos, expected))
{
return false;
}
node = result;
return true;
}
bool ParserWindowList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
auto result = std::make_shared<ASTExpressionList>();
for (;;)
{
auto elem = std::make_shared<ASTWindowListElement>();
ParserIdentifier parser_window_name;
ASTPtr window_name_identifier;
if (!parser_window_name.parse(pos, window_name_identifier, expected))
{
return false;
}
elem->name = getIdentifierName(window_name_identifier);
ParserKeyword keyword_as("AS");
if (!keyword_as.ignore(pos, expected))
{
return false;
}
ParserWindowDefinition parser_window_definition;
if (!parser_window_definition.parse(pos, elem->definition, expected))
{
return false;
}
result->children.push_back(elem);
// If the list countinues, there should be a comma.
ParserToken parser_comma(TokenType::Comma);
if (!parser_comma.ignore(pos))
{
break;
}
}
node = result;
return true;
}
bool ParserCodecDeclarationList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
return ParserList(std::make_unique<ParserIdentifierWithOptionalParameters>(),
std::make_unique<ParserToken>(TokenType::Comma), false).parse(pos, node, expected);
}
bool ParserCodec::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserCodecDeclarationList codecs;
ASTPtr expr_list_args;
if (pos->type != TokenType::OpeningRoundBracket)
return false;
++pos;
if (!codecs.parse(pos, expr_list_args, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
auto function_node = std::make_shared<ASTFunction>();
function_node->name = "CODEC";
function_node->arguments = expr_list_args;
function_node->children.push_back(function_node->arguments);
node = function_node;
return true;
}
bool ParserStatisticType::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserList stat_type_parser(std::make_unique<ParserIdentifierWithOptionalParameters>(),
std::make_unique<ParserToken>(TokenType::Comma), false);
if (pos->type != TokenType::OpeningRoundBracket)
return false;
ASTPtr stat_type;
++pos;
if (!stat_type_parser.parse(pos, stat_type, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
auto function_node = std::make_shared<ASTFunction>();
function_node->name = "STATISTIC";
function_node->arguments = stat_type;
function_node->children.push_back(function_node->arguments);
node = function_node;
return true;
}
bool ParserCollation::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ASTPtr collation;
if (!ParserIdentifier(true).parse(pos, collation, expected))
return false;
// check the collation name is valid
const String name = getIdentifierName(collation);
bool valid_collation = name == "binary" ||
endsWith(name, "_bin") ||
endsWith(name, "_ci") ||
endsWith(name, "_cs") ||
endsWith(name, "_ks");
if (!valid_collation)
return false;
auto collation_node = std::make_shared<ASTCollation>();
collation_node->collation = collation;
node = collation_node;
return true;
}
template <TokenType ...tokens>
static bool isOneOf(TokenType token)
{
return ((token == tokens) || ...);
}
bool ParserCastOperator::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
using enum TokenType;
/// Parse numbers (including decimals), strings, arrays and tuples of them.
const char * data_begin = pos->begin;
const char * data_end = pos->end;
bool is_string_literal = pos->type == StringLiteral;
if (pos->type == Minus)
{
++pos;
if (pos->type != Number)
return false;
data_end = pos->end;
++pos;
}
else if (pos->type == Number || is_string_literal)
{
++pos;
}
else if (isOneOf<OpeningSquareBracket, OpeningRoundBracket>(pos->type))
{
TokenType last_token = OpeningSquareBracket;
std::vector<TokenType> stack;
while (pos.isValid())
{
if (isOneOf<OpeningSquareBracket, OpeningRoundBracket>(pos->type))
{
stack.push_back(pos->type);
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma>(last_token))
return false;
}
else if (pos->type == ClosingSquareBracket)
{
if (isOneOf<Comma, OpeningRoundBracket, Minus>(last_token))
return false;
if (stack.empty() || stack.back() != OpeningSquareBracket)
return false;
stack.pop_back();
}
else if (pos->type == ClosingRoundBracket)
{
if (isOneOf<Comma, OpeningSquareBracket, Minus>(last_token))
return false;
if (stack.empty() || stack.back() != OpeningRoundBracket)
return false;
stack.pop_back();
}
else if (pos->type == Comma)
{
if (isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma, Minus>(last_token))
return false;
if (stack.empty())
break;
}
else if (pos->type == Number)
{
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma, Minus>(last_token))
return false;
}
else if (isOneOf<StringLiteral, Minus>(pos->type))
{
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma>(last_token))
return false;
}
else
{
break;
}
/// Update data_end on every iteration to avoid appearances of extra trailing
/// whitespaces into data. Whitespaces are skipped at operator '++' of Pos.
data_end = pos->end;
last_token = pos->type;
++pos;
}
if (!stack.empty())
return false;
}
else
return false;
ASTPtr type_ast;
if (ParserToken(DoubleColon).ignore(pos, expected)
&& ParserDataType().parse(pos, type_ast, expected))
{
String s;
size_t data_size = data_end - data_begin;
if (is_string_literal)
{
ReadBufferFromMemory buf(data_begin, data_size);
readQuotedStringWithSQLStyle(s, buf);
assert(buf.count() == data_size);
}
else
s = String(data_begin, data_size);
auto literal = std::make_shared<ASTLiteral>(std::move(s));
node = createFunctionCast(literal, type_ast);
return true;
}
return false;
}
bool ParserNull::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword nested_parser("NULL");
if (nested_parser.parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(Null());
return true;
}
else
return false;
}
bool ParserBool::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (ParserKeyword("true").parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(true);
return true;
}
else if (ParserKeyword("false").parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(false);
return true;
}
else
return false;
}
static bool parseNumber(char * buffer, size_t size, bool negative, int base, Field & res)
{
errno = 0; /// Functions strto* don't clear errno.
char * pos_integer = buffer;
UInt64 uint_value = std::strtoull(buffer, &pos_integer, base);
if (pos_integer == buffer + size && errno != ERANGE && (!negative || uint_value <= (1ULL << 63)))
{
/// -0 should be still parsed as UInt instead of Int,
/// because otherwise it is not preserved during formatting-parsing roundtrip
/// (the signedness is lost during formatting)
if (negative && uint_value != 0)
res = static_cast<Int64>(-uint_value);
else
res = uint_value;
return true;
}
return false;
}
bool ParserNumber::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
Pos literal_begin = pos;
bool negative = false;
if (pos->type == TokenType::Minus)
{
++pos;
negative = true;
}
else if (pos->type == TokenType::Plus) /// Leading plus is simply ignored.
++pos;
Field res;
if (!pos.isValid())
return false;
auto try_read_float = [&](const char * it, const char * end)
{
std::string buf(it, end); /// Copying is needed to ensure the string is 0-terminated.
char * str_end;
errno = 0; /// Functions strto* don't clear errno.
/// The usage of strtod is needed, because we parse hex floating point literals as well.
Float64 float_value = std::strtod(buf.c_str(), &str_end);
if (str_end == buf.c_str() + buf.size() && errno != ERANGE)
{
if (float_value < 0)
throw Exception(ErrorCodes::LOGICAL_ERROR,
"Logical error: token number cannot begin with minus, "
"but parsed float number is less than zero.");
if (negative)
float_value = -float_value;
res = float_value;
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
expected.add(pos, "number");
return false;
};
/// NaN and Inf
if (pos->type == TokenType::BareWord)
{
return try_read_float(pos->begin, pos->end);
}
if (pos->type != TokenType::Number)
{
expected.add(pos, "number");
return false;
}
/** Maximum length of number. 319 symbols is enough to write maximum double in decimal form.
* Copy is needed to use strto* functions, which require 0-terminated string.
*/
static constexpr size_t MAX_LENGTH_OF_NUMBER = 319;
char buf[MAX_LENGTH_OF_NUMBER + 1];
size_t buf_size = 0;
for (const auto * it = pos->begin; it != pos->end; ++it)
{
if (*it != '_')
{
buf[buf_size] = *it;
++buf_size;
}
if (unlikely(buf_size > MAX_LENGTH_OF_NUMBER))
{
expected.add(pos, "number");
return false;
}
}
size_t size = buf_size;
buf[size] = 0;
char * start_pos = buf;
if (*start_pos == '0')
{
++start_pos;
--size;