1 | #pragma once |
2 | |
3 | #include <list> |
4 | |
5 | #include <Parsers/IParserBase.h> |
6 | #include <Parsers/CommonParsers.h> |
7 | |
8 | |
9 | namespace DB |
10 | { |
11 | |
12 | /** Consequent pairs of rows: the operator and the corresponding function. For example, "+" -> "plus". |
13 | * The parsing order of the operators is significant. |
14 | */ |
15 | using Operators_t = const char **; |
16 | |
17 | |
18 | /** List of elements separated by something. */ |
19 | class ParserList : public IParserBase |
20 | { |
21 | public: |
22 | ParserList(ParserPtr && elem_parser_, ParserPtr && separator_parser_, bool allow_empty_ = true, char result_separator_ = ',') |
23 | : elem_parser(std::move(elem_parser_)) |
24 | , separator_parser(std::move(separator_parser_)) |
25 | , allow_empty(allow_empty_) |
26 | , result_separator(result_separator_) |
27 | { |
28 | } |
29 | protected: |
30 | const char * getName() const { return "list of elements" ; } |
31 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
32 | private: |
33 | ParserPtr elem_parser; |
34 | ParserPtr separator_parser; |
35 | bool allow_empty; |
36 | char result_separator; |
37 | }; |
38 | |
39 | |
40 | /** An expression with an infix binary left-associative operator. |
41 | * For example, a + b - c + d. |
42 | */ |
43 | class ParserLeftAssociativeBinaryOperatorList : public IParserBase |
44 | { |
45 | private: |
46 | Operators_t operators; |
47 | ParserPtr first_elem_parser; |
48 | ParserPtr remaining_elem_parser; |
49 | |
50 | public: |
51 | /** `operators_` - allowed operators and their corresponding functions |
52 | */ |
53 | ParserLeftAssociativeBinaryOperatorList(Operators_t operators_, ParserPtr && first_elem_parser_) |
54 | : operators(operators_), first_elem_parser(std::move(first_elem_parser_)) |
55 | { |
56 | } |
57 | |
58 | ParserLeftAssociativeBinaryOperatorList(Operators_t operators_, ParserPtr && first_elem_parser_, |
59 | ParserPtr && remaining_elem_parser_) |
60 | : operators(operators_), first_elem_parser(std::move(first_elem_parser_)), |
61 | remaining_elem_parser(std::move(remaining_elem_parser_)) |
62 | { |
63 | } |
64 | |
65 | protected: |
66 | const char * getName() const { return "list, delimited by binary operators" ; } |
67 | |
68 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
69 | }; |
70 | |
71 | |
72 | /** Expression with an infix operator of arbitrary arity. |
73 | * For example, a AND b AND c AND d. |
74 | */ |
75 | class ParserVariableArityOperatorList : public IParserBase |
76 | { |
77 | private: |
78 | const char * infix; |
79 | const char * function_name; |
80 | ParserPtr elem_parser; |
81 | |
82 | public: |
83 | ParserVariableArityOperatorList(const char * infix_, const char * function_, ParserPtr && elem_parser_) |
84 | : infix(infix_), function_name(function_), elem_parser(std::move(elem_parser_)) |
85 | { |
86 | } |
87 | |
88 | protected: |
89 | const char * getName() const { return "list, delimited by operator of variable arity" ; } |
90 | |
91 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
92 | }; |
93 | |
94 | |
95 | /** An expression with a prefix unary operator. |
96 | * Example, NOT x. |
97 | */ |
98 | class ParserPrefixUnaryOperatorExpression : public IParserBase |
99 | { |
100 | private: |
101 | Operators_t operators; |
102 | ParserPtr elem_parser; |
103 | |
104 | public: |
105 | /** `operators_` - allowed operators and their corresponding functions |
106 | */ |
107 | ParserPrefixUnaryOperatorExpression(Operators_t operators_, ParserPtr && elem_parser_) |
108 | : operators(operators_), elem_parser(std::move(elem_parser_)) |
109 | { |
110 | } |
111 | |
112 | protected: |
113 | const char * getName() const { return "expression with prefix unary operator" ; } |
114 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
115 | }; |
116 | |
117 | |
118 | class ParserArrayElementExpression : public IParserBase |
119 | { |
120 | private: |
121 | static const char * operators[]; |
122 | |
123 | protected: |
124 | const char * getName() const { return "array element expression" ; } |
125 | |
126 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
127 | }; |
128 | |
129 | |
130 | class ParserTupleElementExpression : public IParserBase |
131 | { |
132 | private: |
133 | static const char * operators[]; |
134 | |
135 | protected: |
136 | const char * getName() const { return "tuple element expression" ; } |
137 | |
138 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
139 | }; |
140 | |
141 | |
142 | class ParserUnaryMinusExpression : public IParserBase |
143 | { |
144 | private: |
145 | static const char * operators[]; |
146 | ParserPrefixUnaryOperatorExpression operator_parser {operators, std::make_unique<ParserTupleElementExpression>()}; |
147 | |
148 | protected: |
149 | const char * getName() const { return "unary minus expression" ; } |
150 | |
151 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
152 | }; |
153 | |
154 | |
155 | class ParserMultiplicativeExpression : public IParserBase |
156 | { |
157 | private: |
158 | static const char * operators[]; |
159 | ParserLeftAssociativeBinaryOperatorList operator_parser {operators, std::make_unique<ParserUnaryMinusExpression>()}; |
160 | |
161 | protected: |
162 | const char * getName() const { return "multiplicative expression" ; } |
163 | |
164 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
165 | { |
166 | return operator_parser.parse(pos, node, expected); |
167 | } |
168 | }; |
169 | |
170 | |
171 | /// Optional conversion to INTERVAL data type. Example: "INTERVAL x SECOND" parsed as "toIntervalSecond(x)". |
172 | class ParserIntervalOperatorExpression : public IParserBase |
173 | { |
174 | protected: |
175 | ParserMultiplicativeExpression next_parser; |
176 | |
177 | const char * getName() const { return "INTERVAL operator expression" ; } |
178 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
179 | }; |
180 | |
181 | |
182 | class ParserAdditiveExpression : public IParserBase |
183 | { |
184 | private: |
185 | static const char * operators[]; |
186 | ParserLeftAssociativeBinaryOperatorList operator_parser {operators, std::make_unique<ParserIntervalOperatorExpression>()}; |
187 | |
188 | protected: |
189 | const char * getName() const { return "additive expression" ; } |
190 | |
191 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
192 | { |
193 | return operator_parser.parse(pos, node, expected); |
194 | } |
195 | }; |
196 | |
197 | |
198 | class ParserConcatExpression : public IParserBase |
199 | { |
200 | ParserVariableArityOperatorList operator_parser {"||" , "concat" , std::make_unique<ParserAdditiveExpression>()}; |
201 | |
202 | protected: |
203 | const char * getName() const { return "string concatenation expression" ; } |
204 | |
205 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
206 | { |
207 | return operator_parser.parse(pos, node, expected); |
208 | } |
209 | }; |
210 | |
211 | |
212 | class ParserBetweenExpression : public IParserBase |
213 | { |
214 | private: |
215 | ParserConcatExpression elem_parser; |
216 | |
217 | protected: |
218 | const char * getName() const { return "BETWEEN expression" ; } |
219 | |
220 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
221 | }; |
222 | |
223 | |
224 | class ParserComparisonExpression : public IParserBase |
225 | { |
226 | private: |
227 | static const char * operators[]; |
228 | ParserLeftAssociativeBinaryOperatorList operator_parser {operators, std::make_unique<ParserBetweenExpression>()}; |
229 | |
230 | protected: |
231 | const char * getName() const { return "comparison expression" ; } |
232 | |
233 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
234 | { |
235 | return operator_parser.parse(pos, node, expected); |
236 | } |
237 | }; |
238 | |
239 | |
240 | /** Parser for nullity checking with IS (NOT) NULL. |
241 | */ |
242 | class ParserNullityChecking : public IParserBase |
243 | { |
244 | private: |
245 | ParserComparisonExpression elem_parser; |
246 | |
247 | protected: |
248 | const char * getName() const override { return "nullity checking" ; } |
249 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override; |
250 | }; |
251 | |
252 | |
253 | class ParserLogicalNotExpression : public IParserBase |
254 | { |
255 | private: |
256 | static const char * operators[]; |
257 | ParserPrefixUnaryOperatorExpression operator_parser {operators, std::make_unique<ParserNullityChecking>()}; |
258 | |
259 | protected: |
260 | const char * getName() const { return "logical-NOT expression" ; } |
261 | |
262 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
263 | { |
264 | return operator_parser.parse(pos, node, expected); |
265 | } |
266 | }; |
267 | |
268 | |
269 | class ParserLogicalAndExpression : public IParserBase |
270 | { |
271 | private: |
272 | ParserVariableArityOperatorList operator_parser {"AND" , "and" , std::make_unique<ParserLogicalNotExpression>()}; |
273 | |
274 | protected: |
275 | const char * getName() const { return "logical-AND expression" ; } |
276 | |
277 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
278 | { |
279 | return operator_parser.parse(pos, node, expected); |
280 | } |
281 | }; |
282 | |
283 | |
284 | class ParserLogicalOrExpression : public IParserBase |
285 | { |
286 | private: |
287 | ParserVariableArityOperatorList operator_parser {"OR" , "or" , std::make_unique<ParserLogicalAndExpression>()}; |
288 | |
289 | protected: |
290 | const char * getName() const { return "logical-OR expression" ; } |
291 | |
292 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
293 | { |
294 | return operator_parser.parse(pos, node, expected); |
295 | } |
296 | }; |
297 | |
298 | |
299 | /** An expression with ternary operator. |
300 | * For example, a = 1 ? b + 1 : c * 2. |
301 | */ |
302 | class ParserTernaryOperatorExpression : public IParserBase |
303 | { |
304 | private: |
305 | ParserLogicalOrExpression elem_parser; |
306 | |
307 | protected: |
308 | const char * getName() const { return "expression with ternary operator" ; } |
309 | |
310 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
311 | }; |
312 | |
313 | |
314 | class ParserLambdaExpression : public IParserBase |
315 | { |
316 | private: |
317 | ParserTernaryOperatorExpression elem_parser; |
318 | |
319 | protected: |
320 | const char * getName() const { return "lambda expression" ; } |
321 | |
322 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
323 | }; |
324 | |
325 | |
326 | using ParserExpression = ParserLambdaExpression; |
327 | |
328 | |
329 | class ParserExpressionWithOptionalAlias : public IParserBase |
330 | { |
331 | public: |
332 | ParserExpressionWithOptionalAlias(bool allow_alias_without_as_keyword); |
333 | protected: |
334 | ParserPtr impl; |
335 | |
336 | const char * getName() const { return "expression with optional alias" ; } |
337 | |
338 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) |
339 | { |
340 | return impl->parse(pos, node, expected); |
341 | } |
342 | }; |
343 | |
344 | |
345 | /** A comma-separated list of expressions, probably empty. */ |
346 | class ParserExpressionList : public IParserBase |
347 | { |
348 | public: |
349 | ParserExpressionList(bool allow_alias_without_as_keyword_) |
350 | : allow_alias_without_as_keyword(allow_alias_without_as_keyword_) {} |
351 | |
352 | protected: |
353 | bool allow_alias_without_as_keyword; |
354 | |
355 | const char * getName() const { return "list of expressions" ; } |
356 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
357 | }; |
358 | |
359 | |
360 | class ParserNotEmptyExpressionList : public IParserBase |
361 | { |
362 | public: |
363 | ParserNotEmptyExpressionList(bool allow_alias_without_as_keyword) |
364 | : nested_parser(allow_alias_without_as_keyword) {} |
365 | private: |
366 | ParserExpressionList nested_parser; |
367 | protected: |
368 | const char * getName() const { return "not empty list of expressions" ; } |
369 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
370 | }; |
371 | |
372 | |
373 | class ParserOrderByExpressionList : public IParserBase |
374 | { |
375 | protected: |
376 | const char * getName() const { return "order by expression" ; } |
377 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
378 | }; |
379 | |
380 | |
381 | /// Parser for key-value pair, where value can be list of pairs. |
382 | class ParserKeyValuePair : public IParserBase |
383 | { |
384 | protected: |
385 | const char * getName() const override { return "key-value pair" ; } |
386 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override; |
387 | }; |
388 | |
389 | |
390 | /// Parser for list of key-value pairs. |
391 | class ParserKeyValuePairsList : public IParserBase |
392 | { |
393 | protected: |
394 | const char * getName() const override { return "list of pairs" ; } |
395 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override; |
396 | }; |
397 | |
398 | |
399 | class ParserTTLExpressionList : public IParserBase |
400 | { |
401 | protected: |
402 | const char * getName() const { return "ttl expression" ; } |
403 | bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected); |
404 | }; |
405 | |
406 | } |
407 | |