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| 1 | namespace Syntax.Parsers.Definitions is | |
| 2 | use System.Exception | |
| 3 | use IO.Std | |
| 4 | use Ghul.Disposable | |
| 5 | ||
| 6 | use Source | |
| 7 | ||
| 8 | class GLOBAL_LIST( | |
| 9 | pragma_parser: Parser[Trees.Pragmas.PRAGMA], | |
| 10 | definition_parser: Parser[Trees.Definitions.Definition], | |
| 11 | statement_parser: Parser[Trees.Statements.Statement], | |
| 12 | precedence_map: Collections.MutableMap[string,Syntax.Parsers.Expressions.PRECEDENCE], | |
| 13 | precedence_helper: PRAGMA_PRECEDENCE | |
| 14 | ): Base[Trees.Definitions.LIST] is | |
| 15 | description: string => "definition list" | |
| 16 | ||
| 17 | super() | |
| 18 | ||
| 19 | _resync: DEFINITION_RESYNC | |
| 20 | ||
| 21 | init(..) is | |
| 22 | _resync = DEFINITION_RESYNC() | |
| 23 | si | |
| 24 | ||
| 25 | parse(context: CONTEXT) -> Trees.Definitions.LIST is | |
| 26 | let start = context.location | |
| 27 | let end mut = context.location | |
| 28 | let definitions = Collections.LIST[Trees.Definitions.Definition]() | |
| 29 | let statements = Collections.LIST[Trees.Statements.Statement]() | |
| 30 | let file_pragmas = Collections.LIST[Trees.Pragmas.PRAGMA]() | |
| 31 | ||
| 32 | // @@ pragmas are only read here, before the main loop: a | |
| 33 | // whole-file pragma must precede everything else in the file, | |
| 34 | // so one seen once anything has been collected is reported | |
| 35 | // and skipped in the loop below. GLOBAL_LIST is reused as the | |
| 36 | // namespace body parser (see CONTEXT.namespace_depth), so this | |
| 37 | // is gated to depth 0 - a namespace body is never the file | |
| 38 | // root, and `@@` inside one falls through to the misplaced- | |
| 39 | // pragma report in the main loop instead. | |
| 40 | while | |
| 41 | context.namespace_depth == 0 /\ | |
| 42 | context.current.token == Lexical.TOKEN.AT_AT /\ | |
| 43 | !context.is_end_of_file | |
| 44 | do | |
| 45 | let pragma = pragma_parser.parse(context) | |
| 46 | ||
| 47 | if !pragma? then | |
| 48 | break | |
| 49 | fi | |
| 50 | ||
| 51 | file_pragmas.add(pragma) | |
| 52 | ||
| 53 | // A file-level `precedence` applies to the rest of the | |
| 54 | // file's parse and is never restored. | |
| 55 | if pragma.is_name_equal_to("precedence") then | |
| 56 | let operator_name: string mut = "" | |
| 57 | let previous: Syntax.Parsers.Expressions.PRECEDENCE mut = _ | |
| 58 | let had_previous mut = false | |
| 59 | ||
| 60 | precedence_helper.apply(context, pragma, precedence_map, operator_name ref, previous ref, had_previous ref) | |
| 61 | fi | |
| 62 | od | |
| 63 | ||
| 64 | // `si` closes a namespace body (depth > 0); at the file root | |
| 65 | // (depth 0) it is stray input the definition parser reports, so it | |
| 66 | // must not end the loop there. | |
| 67 | while | |
| 68 | !context.is_end_of_file /\ | |
| 69 | (context.namespace_depth == 0 \/ context.current.token != Lexical.TOKEN.SI) | |
| 70 | do | |
| 71 | // A definition or statement attempt that fails without | |
| 72 | // throwing (its parser logs an error and returns null, | |
| 73 | // rather than raising) can leave the tokenizer position | |
| 74 | // exactly where it started - the failed attempt's own | |
| 75 | // speculation is backed out. Without a forced advance | |
| 76 | // here, the loop would re-attempt the identical parse at | |
| 77 | // the identical position forever. | |
| 78 | let attempt_start = context.location | |
| 79 | let progress_start = context.location.start | |
| 80 | let errors_before = context.logger.error_count | |
| 81 | ||
| 82 | // A closing keyword left over by a construct already | |
| 83 | // reported as unclosed is skipped rather than described | |
| 84 | // again as a definition that is not one. At the file root | |
| 85 | // `si` is such a keyword too; inside a namespace the loop | |
| 86 | // above has already stopped on it. | |
| 87 | if context.at_stray_construct_closer(context.namespace_depth == 0) then | |
| 88 | context.next_token() | |
| 89 | ||
| 90 | continue | |
| 91 | fi | |
| 92 | ||
| 93 | try | |
| 94 | if context.current.token == Lexical.TOKEN.AT_AT then | |
| 95 | _reject_misplaced_file_pragma(context) | |
| 96 | // Script mode: at the file root (no enclosing namespace) a | |
| 97 | // leading token that isn't a definition keyword may begin a | |
| 98 | // top-level statement. Inside any namespace this is skipped | |
| 99 | // and parsing is unchanged. | |
| 100 | elif context.namespace_depth == 0 /\ !_is_definition_head(context.current.token) then | |
| 101 | if _is_ambiguous_head(context.current.token) then | |
| 102 | // IDENTIFIER / OPERATOR / [ can each begin a global | |
| 103 | // member or a statement; a shallow peek routes the | |
| 104 | // clear definitions. The rest are parsed as a | |
| 105 | // statement, but speculatively: an incomplete | |
| 106 | // definition that the peek couldn't recognise (e.g. | |
| 107 | // `foo(` with no close) fails to parse as a statement | |
| 108 | // and falls back to the definition parser's recovery. | |
| 109 | if _starts_definition(context) \/ !_try_collect_statement(context, statements) then | |
| 110 | _parse_definition(context, definitions) | |
| 111 | end = _end_of(definitions, end) | |
| 112 | else | |
| 113 | end = _end_of_statement(statements, end) | |
| 114 | fi | |
| 115 | elif _is_statement_head(context.current.token) then | |
| 116 | _parse_statement(context, statements) | |
| 117 | end = _end_of_statement(statements, end) | |
| 118 | else | |
| 119 | // Not a definition keyword and not a statement head: | |
| 120 | // stray input, reported by the definition parser as | |
| 121 | // before. | |
| 122 | _parse_definition(context, definitions) | |
| 123 | end = _end_of(definitions, end) | |
| 124 | fi | |
| 125 | else | |
| 126 | _parse_definition(context, definitions) | |
| 127 | end = _end_of(definitions, end) | |
| 128 | fi | |
| 129 | catch ue: UNWIND_TO_GLOBAL_EXCEPTION | |
| 130 | // carry on from here | |
| 131 | catch e: Exception | |
| 132 | IoC.CONTAINER.instance.logger.exception(context.current.location, e, "parse exception: {e.message}") | |
| 133 | ||
| 134 | while | |
| 135 | !context.is_end_of_file /\ | |
| 136 | context.current.token != Lexical.TOKEN.SI /\ | |
| 137 | context.current.token != Lexical.TOKEN.SEMICOLON | |
| 138 | do | |
| 139 | context.next_token() | |
| 140 | od | |
| 141 | ||
| 142 | if context.is_end_of_file then | |
| 143 | break | |
| 144 | fi | |
| 145 | yrt | |
| 146 | ||
| 147 | _resync.recover(context, attempt_start, errors_before) | |
| 148 | ||
| 149 | if context.location.start == progress_start /\ !context.is_end_of_file then | |
| 150 | context.next_token() | |
| 151 | fi | |
| 152 | od | |
| 153 | ||
| 154 | let result = Trees.Definitions.LIST(start::end, definitions) | |
| 155 | ||
| 156 | if file_pragmas.count > 0 then | |
| 157 | result.file_pragmas = file_pragmas | |
| 158 | fi | |
| 159 | ||
| 160 | // Hand any bare top-level statements to synthesise-top-level-entry, | |
| 161 | // which wraps them into a global entry point. Only reachable at the | |
| 162 | // file root (namespace depth 0). | |
| 163 | // | |
| 164 | // Spanned by the statements themselves rather than by the whole | |
| 165 | // file: the span becomes the synthesised entry's body location, and | |
| 166 | // an incremental edit treats everything inside a re-walked body as | |
| 167 | // re-recorded by that re-walk. A whole-file span therefore discards | |
| 168 | // what the re-walk does not produce - the imports at the head of the | |
| 169 | // file among them - and nothing puts those back. | |
| 170 | if statements.count > 0 then | |
| 171 | result.top_level_statements = | |
| 172 | Trees.Statements.LIST( | |
| 173 | statements[0].location :: statements[statements.count - 1].location, | |
| 174 | statements | |
| 175 | ) | |
| 176 | fi | |
| 177 | ||
| 178 | return result | |
| 179 | si | |
| 180 | ||
| 181 | // A @@ seen once the file has anything in it. Reports where it must | |
| 182 | // have been instead, then hands off to the ordinary pragma parser | |
| 183 | // to consume its tokens (name, arguments, however they're shaped) | |
| 184 | // so the loop can carry on. The parsed pragma itself is discarded: | |
| 185 | // a misplaced one is never applied. | |
| 186 | _reject_misplaced_file_pragma(context: CONTEXT) is | |
| 187 | context.error(context.current.location, "a @@ pragma must precede everything else in the file") | |
| 188 | ||
| 189 | pragma_parser.parse(context) | |
| 190 | ||
| 191 | _skip_semicolon(context) | |
| 192 | si | |
| 193 | ||
| 194 | _parse_definition(context: CONTEXT, definitions: Collections.MutableList[Trees.Definitions.Definition]) is | |
| 195 | let definition = definition_parser.parse(context) | |
| 196 | ||
| 197 | if definition? then | |
| 198 | definitions.add(definition) | |
| 199 | fi | |
| 200 | si | |
| 201 | ||
| 202 | _parse_statement(context: CONTEXT, statements: Collections.MutableList[Trees.Statements.Statement]) is | |
| 203 | let statement: Trees.Statements.Statement? mut = _ | |
| 204 | ||
| 205 | context.in_top_level_statements = true | |
| 206 | ||
| 207 | try | |
| 208 | statement = statement_parser.parse(context) | |
| 209 | finally | |
| 210 | context.in_top_level_statements = false | |
| 211 | yrt | |
| 212 | ||
| 213 | if statement? then | |
| 214 | statements.add(statement) | |
| 215 | _skip_semicolon(context) | |
| 216 | elif !context.is_end_of_file then | |
| 217 | context.next_token() | |
| 218 | fi | |
| 219 | si | |
| 220 | ||
| 221 | // Speculatively parse a statement at an ambiguous head, collecting it | |
| 222 | // and returning true only if it parses cleanly to a statement boundary. | |
| 223 | // Otherwise the tokens are rewound — tokenizer (the exempt bounded-probe | |
| 224 | // kind, so it does not feed the loop detector) and diagnostics — so the | |
| 225 | // caller can hand them to the definition parser instead. A well-formed | |
| 226 | // call commits with no rewind; only an incomplete definition misrouted | |
| 227 | // here takes the fallback. | |
| 228 | _try_collect_statement(context: CONTEXT, statements: Collections.MutableList[Trees.Statements.Statement]) -> bool is | |
| 229 | let use diagnostics_snapshot = context.diagnostics_speculate_then_backtrack() | |
| 230 | let use snapshot = context.tokenizer_speculate_then_backtrack_bounded() | |
| 231 | ||
| 232 | let errors_before = context.logger.error_count | |
| 233 | let away_before = context.errors_away_from_end_of_input | |
| 234 | let head_line = context.location.start_line | |
| 235 | ||
| 236 | let statement: Trees.Statements.Statement? mut = _ | |
| 237 | ||
| 238 | context.in_top_level_statements = true | |
| 239 | ||
| 240 | try | |
| 241 | statement = statement_parser.parse(context) | |
| 242 | finally | |
| 243 | context.in_top_level_statements = false | |
| 244 | yrt | |
| 245 | ||
| 246 | if | |
| 247 | statement? /\ | |
| 248 | !statement.is_poisoned /\ | |
| 249 | context.logger.error_count == errors_before /\ | |
| 250 | ( | |
| 251 | context.current.token == Lexical.TOKEN.SEMICOLON \/ | |
| 252 | context.current.token == Lexical.TOKEN.SI \/ | |
| 253 | context.is_end_of_file \/ | |
| 254 | context.at_inferred_terminator | |
| 255 | ) | |
| 256 | then | |
| 257 | snapshot.commit() | |
| 258 | diagnostics_snapshot.commit() | |
| 259 | ||
| 260 | statements.add(statement) | |
| 261 | _skip_semicolon(context) | |
| 262 | ||
| 263 | return true | |
| 264 | fi | |
| 265 | ||
| 266 | // A statement that runs out of input, with nothing wrong with it | |
| 267 | // but where it stopped, is a statement not finished yet - a call | |
| 268 | // whose arguments are still being typed. Read as a definition it | |
| 269 | // would fail somewhere inside it instead, describing a mistake | |
| 270 | // that is not there. | |
| 271 | if | |
| 272 | statement? /\ | |
| 273 | context.is_end_of_file /\ | |
| 274 | context.logger.error_count > errors_before /\ | |
| 275 | context.errors_away_from_end_of_input == away_before | |
| 276 | then | |
| 277 | snapshot.commit() | |
| 278 | diagnostics_snapshot.commit() | |
| 279 | ||
| 280 | statements.add(statement) | |
| 281 | ||
| 282 | return true | |
| 283 | fi | |
| 284 | ||
| 285 | // Neither reading parses. Where the statement's error is on the | |
| 286 | // line it began, it describes what was written and the peek has | |
| 287 | // already ruled the definition out; an error further down is a | |
| 288 | // statement that swallowed the lines after an unclosed argument | |
| 289 | // list, which is a definition being typed. | |
| 290 | if context.last_error_line == head_line then | |
| 291 | snapshot.commit() | |
| 292 | diagnostics_snapshot.commit() | |
| 293 | ||
| 294 | if statement? then | |
| 295 | statements.add(statement) | |
| 296 | _skip_semicolon(context) | |
| 297 | elif !context.is_end_of_file then | |
| 298 | context.next_token() | |
| 299 | fi | |
| 300 | ||
| 301 | return true | |
| 302 | fi | |
| 303 | ||
| 304 | return false | |
| 305 | si | |
| 306 | ||
| 307 | _end_of(definitions: Collections.List[Trees.Definitions.Definition], previous: Source.LOCATION) -> Source.LOCATION => | |
| 308 | if definitions.count > 0 then definitions[definitions.count - 1].location else previous fi | |
| 309 | ||
| 310 | _end_of_statement(statements: Collections.List[Trees.Statements.Statement], previous: Source.LOCATION) -> Source.LOCATION => | |
| 311 | if statements.count > 0 then statements[statements.count - 1].location else previous fi | |
| 312 | ||
| 313 | // Definition-introducing keywords: everything the definition parser | |
| 314 | // dispatches on that a statement can never begin with. The three | |
| 315 | // tokens a statement *can* also begin with (IDENTIFIER, OPERATOR, | |
| 316 | // SQUARE_OPEN) are deliberately excluded and disambiguated instead. | |
| 317 | _is_definition_head(token: Lexical.TOKEN) -> bool => | |
| 318 | token == Lexical.TOKEN.NAMESPACE \/ | |
| 319 | token == Lexical.TOKEN.USE \/ | |
| 320 | token == Lexical.TOKEN.CLASS \/ | |
| 321 | token == Lexical.TOKEN.TRAIT \/ | |
| 322 | token == Lexical.TOKEN.STRUCT \/ | |
| 323 | token == Lexical.TOKEN.PARTIAL \/ | |
| 324 | token == Lexical.TOKEN.IMPL \/ | |
| 325 | token == Lexical.TOKEN.UNION \/ | |
| 326 | token == Lexical.TOKEN.ENUM \/ | |
| 327 | token == Lexical.TOKEN.AT | |
| 328 | ||
| 329 | // The tokens shared between a global-member definition and a statement. | |
| 330 | _is_ambiguous_head(token: Lexical.TOKEN) -> bool => | |
| 331 | token == Lexical.TOKEN.IDENTIFIER \/ | |
| 332 | token == Lexical.TOKEN.OPERATOR \/ | |
| 333 | token == Lexical.TOKEN.SQUARE_OPEN | |
| 334 | ||
| 335 | // Tokens that unambiguously begin a statement (the statement parser's | |
| 336 | // dispatch set, minus the ambiguous heads handled above). A token that | |
| 337 | // is neither a definition head, an ambiguous head, nor one of these is | |
| 338 | // stray input handled by the definition parser. | |
| 339 | _is_statement_head(token: Lexical.TOKEN) -> bool => | |
| 340 | token == Lexical.TOKEN.PAREN_OPEN \/ | |
| 341 | token == Lexical.TOKEN.NEW \/ | |
| 342 | token == Lexical.TOKEN.CAST \/ | |
| 343 | token == Lexical.TOKEN.ISA \/ | |
| 344 | token == Lexical.TOKEN.TYPEOF \/ | |
| 345 | token == Lexical.TOKEN.INT_LITERAL \/ | |
| 346 | token == Lexical.TOKEN.FLOAT_LITERAL \/ | |
| 347 | token == Lexical.TOKEN.STRING_LITERAL \/ | |
| 348 | token == Lexical.TOKEN.ENTER_STRING \/ | |
| 349 | token == Lexical.TOKEN.CHAR_LITERAL \/ | |
| 350 | token == Lexical.TOKEN.TRUE \/ | |
| 351 | token == Lexical.TOKEN.FALSE \/ | |
| 352 | token == Lexical.TOKEN.NULL \/ | |
| 353 | token == Lexical.TOKEN.SELF \/ | |
| 354 | token == Lexical.TOKEN.SUPER \/ | |
| 355 | token == Lexical.TOKEN.REC \/ | |
| 356 | token == Lexical.TOKEN.VAL \/ | |
| 357 | token == Lexical.TOKEN.LET \/ | |
| 358 | token == Lexical.TOKEN.IF \/ | |
| 359 | token == Lexical.TOKEN.CASE \/ | |
| 360 | token == Lexical.TOKEN.AWAIT \/ | |
| 361 | token == Lexical.TOKEN.ASSERT \/ | |
| 362 | token == Lexical.TOKEN.RETURN \/ | |
| 363 | token == Lexical.TOKEN.YIELD \/ | |
| 364 | token == Lexical.TOKEN.THROW \/ | |
| 365 | token == Lexical.TOKEN.WHILE \/ | |
| 366 | token == Lexical.TOKEN.FOR \/ | |
| 367 | token == Lexical.TOKEN.DO \/ | |
| 368 | token == Lexical.TOKEN.TRY \/ | |
| 369 | token == Lexical.TOKEN.BREAK \/ | |
| 370 | token == Lexical.TOKEN.CONTINUE | |
| 371 | ||
| 372 | // Decide whether an ambiguous head begins a global definition, by a | |
| 373 | // shallow bounded token peek — never a full parse, so it does not feed | |
| 374 | // the speculation-loop detector (its rewind is the exempt bounded-probe | |
| 375 | // kind). Because parameters are always typed, a definition is | |
| 376 | // recognisable from the first couple of tokens: a `: type` annotation, | |
| 377 | // a `(name: ...` / `[name: ...` typed parameter list, or an empty `()` | |
| 378 | // followed by a signature tail. The peek stops at a call argument's | |
| 379 | // opening token, so a formatted string argument is never read into and | |
| 380 | // never mis-lexed. | |
| 381 | _starts_definition(context: CONTEXT) -> bool is | |
| 382 | let use snapshot = context.tokenizer_speculate_then_backtrack_bounded() | |
| 383 | ||
| 384 | let head = context.current.token | |
| 385 | ||
| 386 | context.next_token() | |
| 387 | ||
| 388 | if head == Lexical.TOKEN.SQUARE_OPEN then | |
| 389 | // [i: int] -> T (indexer) vs [a, b]... (array literal). | |
| 390 | return _is_typed_parameter_head(context) | |
| 391 | fi | |
| 392 | ||
| 393 | // IDENTIFIER or OPERATOR. | |
| 394 | let after = context.current.token | |
| 395 | ||
| 396 | // name: type — global variable or typed member. A loop keyword | |
| 397 | // after the colon makes the name a loop label instead, which | |
| 398 | // begins a statement. | |
| 399 | if after == Lexical.TOKEN.COLON then | |
| 400 | context.next_token() | |
| 401 | ||
| 402 | let labelled = context.current.token | |
| 403 | ||
| 404 | return | |
| 405 | labelled != Lexical.TOKEN.FOR /\ | |
| 406 | labelled != Lexical.TOKEN.WHILE /\ | |
| 407 | labelled != Lexical.TOKEN.DO | |
| 408 | fi | |
| 409 | ||
| 410 | // name[T](...) — generic function definition vs name[i]... (index). | |
| 411 | if after == Lexical.TOKEN.SQUARE_OPEN then | |
| 412 | _skip_balanced(context, Lexical.TOKEN.SQUARE_OPEN, Lexical.TOKEN.SQUARE_CLOSE) | |
| 413 | ||
| 414 | return _parameter_list_starts_definition(context) | |
| 415 | fi | |
| 416 | ||
| 417 | // name(...) — function definition vs call statement. | |
| 418 | if after == Lexical.TOKEN.PAREN_OPEN then | |
| 419 | return _parameter_list_starts_definition(context) | |
| 420 | fi | |
| 421 | ||
| 422 | return false | |
| 423 | si | |
| 424 | ||
| 425 | // The current token is expected to be `(`. Distinguishes a parameter | |
| 426 | // list (definition) from a call argument list (statement). A parameter | |
| 427 | // is always `name: type`, so a definition is `()` followed by a | |
| 428 | // definition tail, or `(name: …`; every other shape after `(` — a | |
| 429 | // literal or compound-expression argument, or `(name` continued by | |
| 430 | // anything but `:` (`,`, `)`, `.`, `(`, `[`, an operator, …) — is a | |
| 431 | // call argument list, i.e. a statement. | |
| 432 | _parameter_list_starts_definition(context: CONTEXT) -> bool is | |
| 433 | if context.current.token != Lexical.TOKEN.PAREN_OPEN then | |
| 434 | return false | |
| 435 | fi | |
| 436 | ||
| 437 | // A parameter whose type is missing leaves the list looking | |
| 438 | // like a call's arguments, so what settles it is what follows | |
| 439 | // the list: a body or a return type is a definition written | |
| 440 | // wrongly, and a definition is what it is reported as. | |
| 441 | if _definition_tail_follows(context) then | |
| 442 | return true | |
| 443 | fi | |
| 444 | ||
| 445 | context.next_token() | |
| 446 | ||
| 447 | if context.current.token == Lexical.TOKEN.PAREN_CLOSE then | |
| 448 | context.next_token() | |
| 449 | ||
| 450 | return _begins_definition_tail(context.current.token) | |
| 451 | fi | |
| 452 | ||
| 453 | if context.current.token != Lexical.TOKEN.IDENTIFIER then | |
| 454 | return false | |
| 455 | fi | |
| 456 | ||
| 457 | context.next_token() | |
| 458 | ||
| 459 | return context.current.token == Lexical.TOKEN.COLON | |
| 460 | si | |
| 461 | ||
| 462 | // Whether a definition tail - a body, a return type, a modifier - | |
| 463 | // follows the parenthesised list. A list whose parameters have no | |
| 464 | // types reads as a call passing bare names, and the tail is what | |
| 465 | // says otherwise. | |
| 466 | // | |
| 467 | // An interpolated string ends the peek: its interior lexes | |
| 468 | // according to where the parser is, so running the tokenizer | |
| 469 | // through one from here leaves the real parse reading it | |
| 470 | // differently. A parameter list never contains one, so reaching | |
| 471 | // one means this is a call. | |
| 472 | _definition_tail_follows(context: CONTEXT) -> bool is | |
| 473 | let use snapshot = context.tokenizer_speculate_then_backtrack_bounded() | |
| 474 | ||
| 475 | let depth mut = 0 | |
| 476 | ||
| 477 | while !context.is_end_of_file /\ context.current.token != Lexical.TOKEN.SI do | |
| 478 | let token = context.current.token | |
| 479 | ||
| 480 | if token == Lexical.TOKEN.ENTER_STRING then | |
| 481 | return false | |
| 482 | fi | |
| 483 | ||
| 484 | context.next_token() | |
| 485 | ||
| 486 | if token == Lexical.TOKEN.PAREN_OPEN \/ token == Lexical.TOKEN.SQUARE_OPEN then | |
| 487 | depth = depth + 1 | |
| 488 | elif token == Lexical.TOKEN.PAREN_CLOSE \/ token == Lexical.TOKEN.SQUARE_CLOSE then | |
| 489 | depth = depth - 1 | |
| 490 | ||
| 491 | if depth <= 0 then | |
| 492 | return _begins_definition_tail(context.current.token) | |
| 493 | fi | |
| 494 | fi | |
| 495 | od | |
| 496 | ||
| 497 | return false | |
| 498 | si | |
| 499 | ||
| 500 | // The current token should be the first parameter name, followed by `:`. | |
| 501 | _is_typed_parameter_head(context: CONTEXT) -> bool is | |
| 502 | if context.current.token != Lexical.TOKEN.IDENTIFIER then | |
| 503 | return false | |
| 504 | fi | |
| 505 | ||
| 506 | context.next_token() | |
| 507 | ||
| 508 | return context.current.token == Lexical.TOKEN.COLON | |
| 509 | si | |
| 510 | ||
| 511 | // What can follow the `()` of an empty parameter list in a function | |
| 512 | // definition: the body (`is` / `=>`), a return type (`->`), or a | |
| 513 | // trailing modifier (`static`, `public`, …). A call statement's `()` | |
| 514 | // is followed by a statement continuation (`.`, `;`, an operator, …) | |
| 515 | // instead. | |
| 516 | _begins_definition_tail(token: Lexical.TOKEN) -> bool => | |
| 517 | token == Lexical.TOKEN.IS \/ | |
| 518 | token == Lexical.TOKEN.ARROW_FAT \/ | |
| 519 | token == Lexical.TOKEN.ARROW_THIN \/ | |
| 520 | token == Lexical.TOKEN.STATIC \/ | |
| 521 | token == Lexical.TOKEN.PUBLIC \/ | |
| 522 | token == Lexical.TOKEN.PRIVATE \/ | |
| 523 | token == Lexical.TOKEN.PROTECTED \/ | |
| 524 | token == Lexical.TOKEN.ABSTRACT \/ | |
| 525 | token == Lexical.TOKEN.FIELD | |
| 526 | ||
| 527 | // Consume a balanced bracket group. On entry the current token is the | |
| 528 | // opening bracket; on return it is the token following the matching | |
| 529 | // close (or end-of-input / SI if unterminated). | |
| 530 | _skip_balanced(context: CONTEXT, open: Lexical.TOKEN, close: Lexical.TOKEN) is | |
| 531 | let depth mut = 0 | |
| 532 | ||
| 533 | while !context.is_end_of_file /\ context.current.token != Lexical.TOKEN.SI do | |
| 534 | let token = context.current.token | |
| 535 | ||
| 536 | context.next_token() | |
| 537 | ||
| 538 | if token == open then | |
| 539 | depth = depth + 1 | |
| 540 | elif token == close then | |
| 541 | depth = depth - 1 | |
| 542 | ||
| 543 | if depth <= 0 then | |
| 544 | return | |
| 545 | fi | |
| 546 | fi | |
| 547 | od | |
| 548 | si | |
| 549 | ||
| 550 | _skip_semicolon(context: CONTEXT) is | |
| 551 | if context.current.token == Lexical.TOKEN.SEMICOLON then | |
| 552 | let semicolon = context.current | |
| 553 | context.next_token() | |
| 554 | context.note_written_terminator(semicolon) | |
| 555 | else | |
| 556 | // A top-level statement's boundary never reaches | |
| 557 | // accept_terminator - the terminator is consumed here - so | |
| 558 | // the inlay is recorded here too, or a file of top-level | |
| 559 | // statements shows none. | |
| 560 | context.note_inferred_terminator() | |
| 561 | fi | |
| 562 | si | |
| 563 | si | |
| 564 | si |