Appearance
| 1 | namespace Syntax.Process.Printer is | |
| 2 | use Collections | |
| 3 | ||
| 4 | use Trees | |
| 5 | use Source | |
| 6 | ||
| 7 | use Lexical.TRIVIA | |
| 8 | ||
| 9 | ||
| 10 | // Statement and case formatting: lists, blocks, lets, if statements and expressions, | |
| 11 | // refutable bindings, for loops and case arms. | |
| 12 | partial FORMATTER is | |
| 13 | ||
| 14 | // --- definition / statement lists: leading-trivia interleaving --- | |
| 15 | ||
| 16 | // A file with no namespace can carry bare statements at its root | |
| 17 | // (synthesise-top-level-entry consumes them into a global entry | |
| 18 | // point before declare-symbols), interleaved with global | |
| 19 | // definitions in source order - GHUL.md: "may be interleaved with | |
| 20 | // global definitions, which are visible regardless of where they | |
| 21 | // appear." `definitions` and `top_level_statements` are two | |
| 22 | // separately-ordered runs, so a formatter that rendered every | |
| 23 | // definition before every statement would silently reorder the | |
| 24 | // file. Walk both by source position instead. | |
| 25 | visit(definitions: Definitions.LIST) is | |
| 26 | let items = LIST[Trees.Node]() | |
| 27 | ||
| 28 | for d in definitions do | |
| 29 | items.add(d) | |
| 30 | od | |
| 31 | ||
| 32 | if let statements = definitions.top_level_statements then | |
| 33 | for s in statements do | |
| 34 | items.add(s) | |
| 35 | od | |
| 36 | fi | |
| 37 | ||
| 38 | items.sort((a, b) => a.location.start - b.location.start) | |
| 39 | ||
| 40 | let first mut = true | |
| 41 | ||
| 42 | for item in items do | |
| 43 | flush_leading(item.location.start) | |
| 44 | ||
| 45 | // Nothing has been written yet before the very first item | |
| 46 | // (the root Definitions.LIST is visited before anything | |
| 47 | // else), so `at_line_start` is still at its unset default | |
| 48 | // there - only break between items, never before the first. | |
| 49 | if !first /\ !at_line_start then | |
| 50 | write_line() | |
| 51 | fi | |
| 52 | ||
| 53 | item.accept(self) | |
| 54 | ||
| 55 | first = false | |
| 56 | ||
| 57 | if let variable: Variables.VARIABLE = item then | |
| 58 | if let variable.name? /\ name.name.starts_with("$") then | |
| 59 | write_terminator() | |
| 60 | fi | |
| 61 | fi | |
| 62 | od | |
| 63 | si | |
| 64 | ||
| 65 | visit(list: Statements.LIST) is | |
| 66 | for s in list do | |
| 67 | // A statement ending in a block terminator leaves the line open, | |
| 68 | // and running the next statement onto it produces source that no | |
| 69 | // longer parses - `odwrite_line(...)`. | |
| 70 | if !at_line_start then | |
| 71 | write_line() | |
| 72 | fi | |
| 73 | ||
| 74 | flush_leading(s.location.start) | |
| 75 | s.accept(self) | |
| 76 | od | |
| 77 | si | |
| 78 | ||
| 79 | visit(block: Bodies.BLOCK) is | |
| 80 | // An empty body renders on the header's line - `init() is si` - | |
| 81 | // rather than splitting over two. A body carrying comments keeps | |
| 82 | // the general path so they stay inside the block. | |
| 83 | if block.statements.is_empty /\ ! _has_trivia_before(block.location.end) then | |
| 84 | write("is si") | |
| 85 | return | |
| 86 | fi | |
| 87 | ||
| 88 | write_line("is") | |
| 89 | indent() | |
| 90 | ||
| 91 | // A final statement that reached the body terminator without | |
| 92 | // its `;` is an implicit tail return: it renders as a bare | |
| 93 | // expression, since printing the `;` would turn the return | |
| 94 | // back into a discarded statement. | |
| 95 | let tail_expression: Trees.Expressions.Expression? mut = null | |
| 96 | ||
| 97 | if !block.statements.last_was_terminated then | |
| 98 | if let l = block.statements.last then | |
| 99 | if let te = cast Statements.EXPRESSION?(l) then | |
| 100 | tail_expression = te.expression | |
| 101 | fi | |
| 102 | fi | |
| 103 | fi | |
| 104 | ||
| 105 | if let te = tail_expression then | |
| 106 | let items = LIST[Statements.Statement]() | |
| 107 | ||
| 108 | for s in block.statements do | |
| 109 | items.add(s) | |
| 110 | od | |
| 111 | ||
| 112 | let i mut = 0 | |
| 113 | while i < items.count - 1 do | |
| 114 | // A statement ending in a block terminator leaves the | |
| 115 | // line open, and the next statement's leading comment | |
| 116 | // would be written onto it. So the break comes before | |
| 117 | // the flush, as it does in visit(Statements.LIST). | |
| 118 | if ! at_line_start then | |
| 119 | write_line() | |
| 120 | fi | |
| 121 | ||
| 122 | flush_leading(items[i].location.start) | |
| 123 | items[i].accept(self) | |
| 124 | i = i + 1 | |
| 125 | od | |
| 126 | ||
| 127 | if ! at_line_start then | |
| 128 | write_line() | |
| 129 | fi | |
| 130 | ||
| 131 | flush_leading(items[items.count - 1].location.start) | |
| 132 | te.accept(self) | |
| 133 | write_line("") | |
| 134 | else | |
| 135 | block.statements.accept(self) | |
| 136 | fi | |
| 137 | ||
| 138 | // The last statement may have ended in a block terminator of its | |
| 139 | // own, leaving the line open: `si` must not run onto it. | |
| 140 | if !at_line_start then | |
| 141 | write_line() | |
| 142 | fi | |
| 143 | ||
| 144 | flush_leading(block.location.end) | |
| 145 | outdent() | |
| 146 | write("si") | |
| 147 | si | |
| 148 | ||
| 149 | // --- visits the plain printer never implemented --- | |
| 150 | ||
| 151 | visit(let_in: Expressions.LET_IN) is | |
| 152 | note(let_in.location) | |
| 153 | write("let ") | |
| 154 | if let_in.want_dispose then | |
| 155 | write("use ") | |
| 156 | fi | |
| 157 | let_in.variables.accept(self) | |
| 158 | write(" in ") | |
| 159 | let_in.expression.accept(self) | |
| 160 | si | |
| 161 | ||
| 162 | visit(assert_in: Expressions.ASSERT_IN) is | |
| 163 | note(assert_in.location) | |
| 164 | write("assert ") | |
| 165 | assert_in.condition.accept(self) | |
| 166 | if assert_in.message? then | |
| 167 | write(" else ") | |
| 168 | assert_in.message!.accept(self) | |
| 169 | fi | |
| 170 | write(" in ") | |
| 171 | assert_in.expression.accept(self) | |
| 172 | si | |
| 173 | ||
| 174 | visit(recurse: Expressions.RECURSE) is | |
| 175 | note(recurse.location) | |
| 176 | write("rec") | |
| 177 | si | |
| 178 | ||
| 179 | // --- faithfulness fix: an `if ... fi` in expression position is | |
| 180 | // Expressions.STATEMENT wrapping Statements.IF. The inherited | |
| 181 | // visit renders the statement form — `;`-terminated branch | |
| 182 | // bodies plus a trailing `;` — which is invalid in expression | |
| 183 | // position. Render the expression form instead. --- | |
| 184 | ||
| 185 | visit(statement: Expressions.STATEMENT) is | |
| 186 | note(statement.location) | |
| 187 | ||
| 188 | if let if_statement: Statements.IF = statement.statement then | |
| 189 | emit_if_expression(if_statement) | |
| 190 | elif let case_statement: Statements.CASE = statement.statement then | |
| 191 | emit_case_expression(case_statement) | |
| 192 | elif let for_statement: Statements.FOR = statement.statement then | |
| 193 | emit_for_expression(for_statement) | |
| 194 | elif let do_statement: Statements.DO = statement.statement then | |
| 195 | emit_do_expression(do_statement) | |
| 196 | elif let throw_statement: Statements.THROW = statement.statement then | |
| 197 | // `=> throw E` stubs a diverging body. The statement form | |
| 198 | // writes its own `;`, which the member's `after_body` would | |
| 199 | // duplicate - render the expression form instead. | |
| 200 | write("throw") | |
| 201 | if throw_statement.expression? then | |
| 202 | write(" ") | |
| 203 | throw_statement.expression.accept(self) | |
| 204 | fi | |
| 205 | else | |
| 206 | statement.statement.accept(self) | |
| 207 | fi | |
| 208 | si | |
| 209 | ||
| 210 | // `val ... lav` block expression. The keyword pair is load- | |
| 211 | // bearing; each statement renders normally (with its own `;`) | |
| 212 | // and the surrounding context decides whether the block's value | |
| 213 | // is consumed. | |
| 214 | visit(block: Expressions.VAL_BLOCK) is | |
| 215 | note(block.location) | |
| 216 | ||
| 217 | if block.is_parenthesised then | |
| 218 | write_line("(") | |
| 219 | indent() | |
| 220 | block.body.accept(self) | |
| 221 | outdent() | |
| 222 | write(")") | |
| 223 | else | |
| 224 | write_line("val") | |
| 225 | indent() | |
| 226 | block.body.accept(self) | |
| 227 | outdent() | |
| 228 | write("lav") | |
| 229 | fi | |
| 230 | si | |
| 231 | ||
| 232 | // --- faithfulness fix: the inherited visit(Statements.LET) never | |
| 233 | // emits the `use` disposal keyword, so `let use x = e` round-trips | |
| 234 | // to `let x = e`, silently dropping the disposal. --- | |
| 235 | ||
| 236 | visit(l: Statements.LET) is | |
| 237 | write("let ") | |
| 238 | ||
| 239 | if l.want_dispose then | |
| 240 | write("use ") | |
| 241 | fi | |
| 242 | ||
| 243 | _in_let = true | |
| 244 | l.variables.accept(self) | |
| 245 | _in_let = false | |
| 246 | write_terminator() | |
| 247 | si | |
| 248 | ||
| 249 | // --- faithfulness fix: the inherited visit(Statements.IF) ignores a | |
| 250 | // branch binding, so `if let v = e then` renders as a bare `else` | |
| 251 | // with the binding dropped. --- | |
| 252 | ||
| 253 | visit(if_statement: Statements.IF) is | |
| 254 | note(if_statement.location) | |
| 255 | ||
| 256 | let branches = LIST[Statements.IF_BRANCH]() | |
| 257 | for b in if_statement.branches do | |
| 258 | branches.add(b) | |
| 259 | od | |
| 260 | ||
| 261 | let first mut = true | |
| 262 | let i mut = 0 | |
| 263 | for branch in branches do | |
| 264 | // The previous branch ended with a statement that may | |
| 265 | // itself have closed a block, leaving the line open: | |
| 266 | // `elif` and `else` must not run onto it. | |
| 267 | if !first /\ !at_line_start then | |
| 268 | write_line() | |
| 269 | fi | |
| 270 | ||
| 271 | if let branch.binding? then | |
| 272 | if first then | |
| 273 | write("if let ") | |
| 274 | else | |
| 275 | write("elif let ") | |
| 276 | fi | |
| 277 | binding.accept(self) | |
| 278 | if let branch.condition? then | |
| 279 | write(" /\\ ") | |
| 280 | condition.accept(self) | |
| 281 | fi | |
| 282 | write_line(" then") | |
| 283 | elif let branch.condition? then | |
| 284 | if first then | |
| 285 | write("if ") | |
| 286 | else | |
| 287 | write("elif ") | |
| 288 | fi | |
| 289 | condition.accept(self) | |
| 290 | write_line(" then") | |
| 291 | else | |
| 292 | write_line("else") | |
| 293 | fi | |
| 294 | ||
| 295 | indent() | |
| 296 | branch.body.accept(self) | |
| 297 | ||
| 298 | // A comment after the branch's last statement belongs inside | |
| 299 | // the branch: consume it while still indented, or it is | |
| 300 | // emitted after the `fi` - or, ahead of the next clause's | |
| 301 | // keyword, trails that keyword's line instead. | |
| 302 | flush_leading( | |
| 303 | if i + 1 < branches.count then | |
| 304 | branches[i + 1].location.start | |
| 305 | else | |
| 306 | if_statement.location.end | |
| 307 | fi) | |
| 308 | ||
| 309 | outdent() | |
| 310 | ||
| 311 | first = false | |
| 312 | i = i + 1 | |
| 313 | od | |
| 314 | ||
| 315 | // The last branch's body may have ended in a block terminator | |
| 316 | // of its own, leaving the line open: `fi` must not run onto it. | |
| 317 | if !at_line_start then | |
| 318 | write_line() | |
| 319 | fi | |
| 320 | ||
| 321 | write_line("fi") | |
| 322 | si | |
| 323 | ||
| 324 | // --- the REFUTABLE_BINDING node carries the `pattern[: T] = | |
| 325 | // scrutinee[ /\ guard]` shape that drives an `if let` arm, | |
| 326 | // or the leaf-name shorthand `path?` / `path: T` when the | |
| 327 | // variable name was inferred from the path. The `if let ` / | |
| 328 | // `elif let ` keyword is emitted by the surrounding | |
| 329 | // visit(Statements.IF); this renders the clause payload | |
| 330 | // only. --- | |
| 331 | ||
| 332 | visit(rb: Statements.REFUTABLE_BINDING) is | |
| 333 | note(rb.location) | |
| 334 | ||
| 335 | let first mut = true | |
| 336 | ||
| 337 | for c in rb.clauses do | |
| 338 | if !first then | |
| 339 | write(", ") | |
| 340 | fi | |
| 341 | ||
| 342 | if c.is_inferred_name then | |
| 343 | c.scrutinee.accept(self) | |
| 344 | ||
| 345 | if let c.narrow_type_expression? then | |
| 346 | write(": ") | |
| 347 | narrow_type_expression.accept(self) | |
| 348 | else | |
| 349 | write("?") | |
| 350 | fi | |
| 351 | else | |
| 352 | c.pattern.accept(self) | |
| 353 | ||
| 354 | if let c.narrow_type_expression? then | |
| 355 | write(": ") | |
| 356 | narrow_type_expression.accept(self) | |
| 357 | fi | |
| 358 | ||
| 359 | write(" = ") | |
| 360 | c.scrutinee.accept(self) | |
| 361 | fi | |
| 362 | ||
| 363 | if let c.guard? then | |
| 364 | write(" /\\ ") | |
| 365 | guard.accept(self) | |
| 366 | fi | |
| 367 | ||
| 368 | first = false | |
| 369 | od | |
| 370 | si | |
| 371 | ||
| 372 | // --- faithfulness fix: the inherited visit(Statements.FOR) emits | |
| 373 | // `for` with a trailing newline, stranding it on its own line. --- | |
| 374 | ||
| 375 | visit(for_statement: Statements.FOR) is | |
| 376 | note(for_statement.location) | |
| 377 | ||
| 378 | write("for ") | |
| 379 | ||
| 380 | let variable = for_statement.variable | |
| 381 | if variable? then | |
| 382 | variable.accept(self) | |
| 383 | fi | |
| 384 | ||
| 385 | write(" in ") | |
| 386 | ||
| 387 | let expression = for_statement.expression | |
| 388 | if expression? then | |
| 389 | expression.accept(self) | |
| 390 | fi | |
| 391 | ||
| 392 | write_line(" do") | |
| 393 | ||
| 394 | indent() | |
| 395 | ||
| 396 | let body = for_statement.body | |
| 397 | if body? then | |
| 398 | body.accept(self) | |
| 399 | fi | |
| 400 | ||
| 401 | // A comment after the body's last statement belongs inside the | |
| 402 | // loop: consume it while still indented, or it is emitted after | |
| 403 | // the `od`. | |
| 404 | flush_leading(for_statement.location.end) | |
| 405 | ||
| 406 | outdent() | |
| 407 | ||
| 408 | // Nested blocks each end with their own terminator, and the inner | |
| 409 | // one leaves the line open: `od` must not run onto it. | |
| 410 | if !at_line_start then | |
| 411 | write_line() | |
| 412 | fi | |
| 413 | ||
| 414 | write("od") | |
| 415 | si | |
| 416 | ||
| 417 | // The base visit renders the statement form but never consumes the | |
| 418 | // trivia queue, so a comment trailing the body is emitted after the | |
| 419 | // `od` rather than inside the loop. | |
| 420 | visit(`do: Statements.DO) is | |
| 421 | note(`do.location) | |
| 422 | ||
| 423 | if let `do.binding? then | |
| 424 | write("while let ") | |
| 425 | binding.accept(self) | |
| 426 | write(" ") | |
| 427 | elif let `do.condition? then | |
| 428 | write("while ") | |
| 429 | condition.accept(self) | |
| 430 | write(" ") | |
| 431 | fi | |
| 432 | ||
| 433 | write_line("do") | |
| 434 | indent() | |
| 435 | `do.body.accept(self) | |
| 436 | ||
| 437 | // A comment after the body's last statement belongs inside the | |
| 438 | // loop: consume it while still indented, or it is emitted after | |
| 439 | // the `od`. | |
| 440 | flush_leading(`do.location.end) | |
| 441 | ||
| 442 | outdent() | |
| 443 | ||
| 444 | // Nested blocks each end with their own terminator, and the inner | |
| 445 | // one leaves the line open: `od` must not run onto it. | |
| 446 | if !at_line_start then | |
| 447 | write_line() | |
| 448 | fi | |
| 449 | ||
| 450 | write_line("od") | |
| 451 | si | |
| 452 | ||
| 453 | // The base visit renders the statement form but never consumes the | |
| 454 | // trivia queue, so a comment trailing a body is emitted after the | |
| 455 | // `yrt` - or, ahead of a `catch` or `finally` keyword, trails that | |
| 456 | // keyword's line - rather than staying in the body it was written in. | |
| 457 | visit(`try: Statements.TRY) is | |
| 458 | note(`try.location) | |
| 459 | ||
| 460 | write_line("try") | |
| 461 | indent() | |
| 462 | `try.body.accept(self) | |
| 463 | ||
| 464 | let catches = LIST[Statements.CATCH]() | |
| 465 | for c in `try.catches do | |
| 466 | catches.add(c) | |
| 467 | od | |
| 468 | ||
| 469 | flush_leading(next_clause_start(`try, catches, 0)) | |
| 470 | ||
| 471 | outdent() | |
| 472 | ||
| 473 | let i mut = 0 | |
| 474 | for c in catches do | |
| 475 | // The body may have ended in a nested block, whose own | |
| 476 | // terminator leaves the line open: `catch` must not run | |
| 477 | // onto it, as the `yrt` below does not. | |
| 478 | if !at_line_start then | |
| 479 | write_line() | |
| 480 | fi | |
| 481 | ||
| 482 | write("catch ") | |
| 483 | ||
| 484 | if let c.variable? then | |
| 485 | variable.accept(self) | |
| 486 | fi | |
| 487 | write_line() | |
| 488 | ||
| 489 | indent() | |
| 490 | c.body.accept(self) | |
| 491 | ||
| 492 | flush_leading(next_clause_start(`try, catches, i + 1)) | |
| 493 | ||
| 494 | outdent() | |
| 495 | ||
| 496 | i = i + 1 | |
| 497 | od | |
| 498 | ||
| 499 | let `finally = `try.`finally | |
| 500 | ||
| 501 | if `finally? then | |
| 502 | if !at_line_start then | |
| 503 | write_line() | |
| 504 | fi | |
| 505 | ||
| 506 | write_line("finally") | |
| 507 | indent() | |
| 508 | `finally.accept(self) | |
| 509 | ||
| 510 | // A comment after the last statement of the finally body | |
| 511 | // belongs inside it: consume it while still indented, or it | |
| 512 | // is emitted after the `yrt`. | |
| 513 | flush_leading(`try.location.end) | |
| 514 | ||
| 515 | outdent() | |
| 516 | fi | |
| 517 | ||
| 518 | if !at_line_start then | |
| 519 | write_line() | |
| 520 | fi | |
| 521 | ||
| 522 | write_line("yrt") | |
| 523 | si | |
| 524 | ||
| 525 | // The position a body's trailing trivia is flushed against: the next | |
| 526 | // `catch` clause when one follows, the `finally` body if the next | |
| 527 | // thing is a finally, and the end of the try otherwise. | |
| 528 | next_clause_start(`try: Statements.TRY, catches: LIST[Statements.CATCH], next: int) -> int is | |
| 529 | if next < catches.count then | |
| 530 | return catches[next].location.start | |
| 531 | fi | |
| 532 | ||
| 533 | let `finally = `try.`finally | |
| 534 | ||
| 535 | if `finally? then | |
| 536 | return `finally.location.start | |
| 537 | fi | |
| 538 | ||
| 539 | return `try.location.end | |
| 540 | si | |
| 541 | ||
| 542 | emit_if_expression(if_statement: Statements.IF) is | |
| 543 | _builder.begin_group() | |
| 544 | ||
| 545 | let first mut = true | |
| 546 | for branch in if_statement.branches do | |
| 547 | if !first /\ !at_line_start then | |
| 548 | _builder.line() | |
| 549 | fi | |
| 550 | ||
| 551 | // Trivia (a comment, a blank line) between one branch's | |
| 552 | // last statement and the next branch's keyword has to be | |
| 553 | // consumed here - otherwise it stays in the trivia queue | |
| 554 | // and surfaces later, wherever the next flush_leading | |
| 555 | // happens to land. | |
| 556 | if !first then | |
| 557 | flush_leading(branch.location.start) | |
| 558 | fi | |
| 559 | ||
| 560 | if let branch.binding? then | |
| 561 | if first then | |
| 562 | write("if let ") | |
| 563 | else | |
| 564 | write("elif let ") | |
| 565 | fi | |
| 566 | binding.accept(self) | |
| 567 | if let branch.condition? then | |
| 568 | write(" /\\ ") | |
| 569 | condition.accept(self) | |
| 570 | fi | |
| 571 | write(" then") | |
| 572 | elif let branch.condition? then | |
| 573 | if first then | |
| 574 | write("if ") | |
| 575 | else | |
| 576 | write("elif ") | |
| 577 | fi | |
| 578 | condition.accept(self) | |
| 579 | write(" then") | |
| 580 | else | |
| 581 | write("else") | |
| 582 | fi | |
| 583 | ||
| 584 | _builder.begin_nest(4) | |
| 585 | _builder.line() | |
| 586 | emit_branch_value(branch.body) | |
| 587 | ||
| 588 | // A statement arm - a `return`, say - writes its own line | |
| 589 | // break. The soft break that separates it from the next | |
| 590 | // keyword would then be a second one, and the blank line | |
| 591 | // it leaves comes back as another on every reformat. | |
| 592 | _builder.end_nest() | |
| 593 | ||
| 594 | first = false | |
| 595 | od | |
| 596 | ||
| 597 | flush_leading(if_statement.location.end) | |
| 598 | ||
| 599 | if !at_line_start then | |
| 600 | _builder.line() | |
| 601 | fi | |
| 602 | ||
| 603 | write("fi") | |
| 604 | _builder.end_group() | |
| 605 | si | |
| 606 | ||
| 607 | // Emit an if-expression branch body. The branch's value is its last | |
| 608 | // bare expression (no `;`); any leading statements render | |
| 609 | // normally. | |
| 610 | emit_branch_value(body: Statements.LIST) is | |
| 611 | let statements = LIST[Statements.Statement]() | |
| 612 | for s in body do | |
| 613 | statements.add(s) | |
| 614 | od | |
| 615 | ||
| 616 | let i mut = 0 | |
| 617 | while i < statements.count do | |
| 618 | let s = statements[i] | |
| 619 | let is_last = i == statements.count - 1 | |
| 620 | ||
| 621 | // Leading trivia (blank lines, comments) between arm-body | |
| 622 | // statements has to be consumed here, in place - otherwise | |
| 623 | // it stays in the trivia queue and surfaces later, at | |
| 624 | // whichever definition or statement next calls | |
| 625 | // flush_leading, stacking with whatever blank line already | |
| 626 | // belongs there. | |
| 627 | // A statement ending in a block terminator - an arm body's | |
| 628 | // `od` - leaves the line open, and the next statement's | |
| 629 | // leading comment would be written onto it, so the break | |
| 630 | // comes first. The arm's own opening break is a soft one, | |
| 631 | // which `at_line_start` does not see, so this asks only | |
| 632 | // about a break the previous statement should have left. | |
| 633 | if i > 0 /\ !at_line_start then | |
| 634 | write_line() | |
| 635 | fi | |
| 636 | ||
| 637 | flush_leading(s.location.start) | |
| 638 | ||
| 639 | // A tail statement can itself be an if/case/for/do used as | |
| 640 | // a value (implicit tail return). Each of those has its own | |
| 641 | // no-trailing-terminator expression renderer, matching the | |
| 642 | // dispatch in visit(Expressions.STATEMENT); the ordinary | |
| 643 | // statement-form renderers (`visit(Statements.IF)` and | |
| 644 | // friends) are for a statement in statement position, and | |
| 645 | // terminate their own line. | |
| 646 | if is_last /\ isa Statements.EXPRESSION(s) then | |
| 647 | let expression_statement = cast Statements.EXPRESSION(s) | |
| 648 | expression_statement.expression.accept(self) | |
| 649 | elif is_last /\ isa Statements.IF(s) then | |
| 650 | emit_if_expression(cast Statements.IF(s)) | |
| 651 | elif is_last /\ isa Statements.CASE(s) then | |
| 652 | emit_case_expression(cast Statements.CASE(s)) | |
| 653 | elif is_last /\ isa Statements.FOR(s) then | |
| 654 | emit_for_expression(cast Statements.FOR(s)) | |
| 655 | elif is_last /\ isa Statements.DO(s) then | |
| 656 | emit_do_expression(cast Statements.DO(s)) | |
| 657 | else | |
| 658 | s.accept(self) | |
| 659 | fi | |
| 660 | i = i + 1 | |
| 661 | od | |
| 662 | si | |
| 663 | ||
| 664 | // Loop expressions render like their statement forms but end at | |
| 665 | // the closing keyword with no trailing `;` — the consuming | |
| 666 | // context owns statement termination — and the body's value is | |
| 667 | // its last bare expression, as in an if-expression branch. | |
| 668 | emit_for_expression(for_statement: Statements.FOR) is | |
| 669 | write("for ") | |
| 670 | ||
| 671 | if let for_statement.variable? then | |
| 672 | variable.accept(self) | |
| 673 | fi | |
| 674 | ||
| 675 | write(" in ") | |
| 676 | ||
| 677 | if let for_statement.expression? then | |
| 678 | expression.accept(self) | |
| 679 | fi | |
| 680 | ||
| 681 | write_line(" do") | |
| 682 | indent() | |
| 683 | ||
| 684 | if let for_statement.body? then | |
| 685 | body.accept(self) | |
| 686 | fi | |
| 687 | ||
| 688 | outdent() | |
| 689 | ||
| 690 | // Nested blocks each end with their own terminator, and the inner | |
| 691 | // one leaves the line open: `od` must not run onto it. | |
| 692 | if !at_line_start then | |
| 693 | write_line() | |
| 694 | fi | |
| 695 | ||
| 696 | write("od") | |
| 697 | si | |
| 698 | ||
| 699 | emit_do_expression(do_statement: Statements.DO) is | |
| 700 | if let do_statement.binding? then | |
| 701 | write("while let ") | |
| 702 | binding.accept(self) | |
| 703 | write(" ") | |
| 704 | elif let do_statement.condition? then | |
| 705 | write("while ") | |
| 706 | condition.accept(self) | |
| 707 | write(" ") | |
| 708 | fi | |
| 709 | ||
| 710 | write_line("do") | |
| 711 | indent() | |
| 712 | do_statement.body.accept(self) | |
| 713 | outdent() | |
| 714 | ||
| 715 | // Nested blocks each end with their own terminator, and the inner | |
| 716 | // one leaves the line open: `od` must not run onto it. | |
| 717 | if !at_line_start then | |
| 718 | write_line() | |
| 719 | fi | |
| 720 | ||
| 721 | write("od") | |
| 722 | si | |
| 723 | ||
| 724 | // --- faithfulness fix: `case` statement / expression. The base | |
| 725 | // printer emits a legacy `when X :` / `default` / `esac` | |
| 726 | // shape; the parser accepts only `when X then` / `else` / | |
| 727 | // `esac`. Binding-pattern arms (`when v: int then`) and | |
| 728 | // literal-leaf patterns live on the arm's `pattern` field | |
| 729 | // rather than its `expressions` list and must be emitted | |
| 730 | // from there. --- | |
| 731 | ||
| 732 | visit(`case: Statements.CASE) is | |
| 733 | emit_case_header(`case) | |
| 734 | ||
| 735 | let i mut = 0 | |
| 736 | for m in `case.matches do | |
| 737 | // A comment after an arm's last statement belongs inside the | |
| 738 | // arm: bound the flush by the next arm's keyword (or the | |
| 739 | // `esac`), or it trails the next keyword's line. | |
| 740 | let limit = | |
| 741 | if i + 1 < `case.matches.count then | |
| 742 | `case.matches[i + 1].location.start | |
| 743 | else | |
| 744 | `case.location.end | |
| 745 | fi | |
| 746 | ||
| 747 | emit_case_match_at(m, false, limit) | |
| 748 | i = i + 1 | |
| 749 | od | |
| 750 | ||
| 751 | // An arm ending in a nested block leaves the line open after | |
| 752 | // that block's terminator: `esac` must not run onto it. | |
| 753 | if !at_line_start then | |
| 754 | write_line() | |
| 755 | fi | |
| 756 | ||
| 757 | write_line("esac") | |
| 758 | si | |
| 759 | ||
| 760 | visit(match: Statements.CASE_MATCH) is | |
| 761 | emit_case_match_at(match, false, match.location.end) | |
| 762 | si | |
| 763 | ||
| 764 | emit_case_header(case_statement: Statements.CASE) is | |
| 765 | note(case_statement.location) | |
| 766 | write("case ") | |
| 767 | case_statement.expression.accept(self) | |
| 768 | write_line() | |
| 769 | si | |
| 770 | ||
| 771 | emit_case_match_at(match: Statements.CASE_MATCH, as_expression: bool, limit: int) is | |
| 772 | note(match.location) | |
| 773 | ||
| 774 | if let match.pattern? then | |
| 775 | write("when ") | |
| 776 | pattern.accept(self) | |
| 777 | ||
| 778 | if let match.guard? then | |
| 779 | write(" /\\ ") | |
| 780 | guard.accept(self) | |
| 781 | fi | |
| 782 | ||
| 783 | write_line(" then") | |
| 784 | elif match.expressions? then | |
| 785 | write("when ") | |
| 786 | let first mut = true | |
| 787 | for e in match.expressions! do | |
| 788 | if !first then | |
| 789 | write(", ") | |
| 790 | fi | |
| 791 | e.accept(self) | |
| 792 | first = false | |
| 793 | od | |
| 794 | write_line(" then") | |
| 795 | else | |
| 796 | write_line("else") | |
| 797 | fi | |
| 798 | ||
| 799 | indent() | |
| 800 | ||
| 801 | if as_expression then | |
| 802 | emit_branch_value(match.statements) | |
| 803 | write_line() | |
| 804 | else | |
| 805 | match.statements.accept(self) | |
| 806 | fi | |
| 807 | ||
| 808 | // A comment after the arm's last statement belongs inside the | |
| 809 | // arm: consume it while still indented, or it is emitted after | |
| 810 | // the `esac` - or trails the next arm keyword's line. | |
| 811 | flush_leading(limit) | |
| 812 | ||
| 813 | outdent() | |
| 814 | si | |
| 815 | ||
| 816 | emit_case_expression(case_statement: Statements.CASE) is | |
| 817 | emit_case_header(case_statement) | |
| 818 | ||
| 819 | let i mut = 0 | |
| 820 | for m in case_statement.matches do | |
| 821 | let limit = | |
| 822 | if i + 1 < case_statement.matches.count then | |
| 823 | case_statement.matches[i + 1].location.start | |
| 824 | else | |
| 825 | case_statement.location.end | |
| 826 | fi | |
| 827 | ||
| 828 | emit_case_match_at(m, true, limit) | |
| 829 | i = i + 1 | |
| 830 | od | |
| 831 | ||
| 832 | write("esac") | |
| 833 | si | |
| 834 | si | |
| 835 | si |