summary refs log tree commit diff stats
path: root/LICENSE
diff options
context:
space:
mode:
Diffstat (limited to 'LICENSE')
0 files changed, 0 insertions, 0 deletions
id='n27' href='#n27'>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
## experimental compiler to translate programs written in a generic
## expression-oriented language called 'lambda' into Mu

# incomplete; code generator not done
# potential enhancements:
#   symbol table
#   poor man's macros
#     substitute one instruction with multiple, parameterized by ingredients and products

scenario convert-lambda [
  run [
    local-scope
    1:text/raw <- lambda-to-mu [(add a (multiply b c))]
    2:@:char/raw <- copy *1:text/raw
  ]
  memory-should-contain [
    2:array:character <- [t1 <- multiply b c
result <- add a t1]
  ]
]

def lambda-to-mu in:text -> out:text [
  local-scope
  load-ingredients
  out <- copy 0
  cells:&:cell <- parse in
  out <- to-mu cells
]

# 'parse' will turn lambda expressions into trees made of cells
exclusive-container cell [
  atom:text
  pair:pair
]

# printed below as < first | rest >
container pair [
  first:&:cell
  rest:&:cell
]

def new-atom name:text -> result:&:cell [
  local-scope
  load-ingredients
  result <- new cell:type
  *result <- merge 0/tag:atom, name
]

def new-pair a:&:cell, b:&:cell -> result:&:cell [
  local-scope
  load-ingredients
  result <- new cell:type
  *result <- merge 1/tag:pair, a/first, b/rest
]

def is-atom? x:&:cell -> result:bool [
  local-scope
  load-ingredients
  return-unless x, 0/false
  _, result <- maybe-convert *x, atom:variant
]

def is-pair? x:&:cell -> result:bool [
  local-scope
  load-ingredients
  return-unless x, 0/false
  _, result <- maybe-convert *x, pair:variant
]

scenario atom-is-not-pair [
  local-scope
  s:text <- new [a]
  x:&:cell <- new-atom s
  10:bool/raw <- is-atom? x
  11:bool/raw <- is-pair? x
  memory-should-contain [
    10 <- 1
    11 <- 0
  ]
]

scenario pair-is-not-atom [
  local-scope
  # construct (a . nil)
  s:text <- new [a]
  x:&:cell <- new-atom s
  y:&:cell <- new-pair x, 0/nil
  10:bool/raw <- is-atom? y
  11:bool/raw <- is-pair? y
  memory-should-contain [
    10 <- 0
    11 <- 1
  ]
]

def atom-match? x:&:cell, pat:text -> result:bool [
  local-scope
  load-ingredients
  s:text, is-atom?:bool <- maybe-convert *x, atom:variant
  return-unless is-atom?, 0/false
  result <- equal pat, s
]

scenario atom-match [
  local-scope
  x:&:cell <- new-atom [abc]
  10:bool/raw <- atom-match? x, [abc]
  memory-should-contain [
    10 <- 1
  ]
]

def first x:&:cell -> result:&:cell [
  local-scope
  load-ingredients
  pair:pair, pair?:bool <- maybe-convert *x, pair:variant
  return-unless pair?, 0/nil
  result <- get pair, first:offset
]

def rest x:&:cell -> result:&:cell [
  local-scope
  load-ingredients
  pair:pair, pair?:bool <- maybe-convert *x, pair:variant
  return-unless pair?, 0/nil
  result <- get pair, rest:offset
]

def set-first base:&:cell, new-first:&:cell -> base:&:cell [
  local-scope
  load-ingredients
  pair:pair, is-pair?:bool <- maybe-convert *base, pair:variant
  return-unless is-pair?
  pair <- put pair, first:offset, new-first
  *base <- merge 1/pair, pair
]

def set-rest base:&:cell, new-rest:&:cell -> base:&:cell [
  local-scope
  load-ingredients
  pair:pair, is-pair?:bool <- maybe-convert *base, pair:variant
  return-unless is-pair?
  pair <- put pair, rest:offset, new-rest
  *base <- merge 1/pair, pair
]

scenario cell-operations-on-atom [
  local-scope
  s:text <- new [a]
  x:&:cell <- new-atom s
  10:&:cell/raw <- first x
  11:&:cell/raw <- rest x
  memory-should-contain [
    10 <- 0  # first is nil
    11 <- 0  # rest is nil
  ]
]

scenario cell-operations-on-pair [
  local-scope
  # construct (a . nil)
  s:text <- new [a]
  x:&:cell <- new-atom s
  y:&:cell <- new-pair x, 0/nil
  x2:&:cell <- first y
  10:bool/raw <- equal x, x2
  11:&:cell/raw <- rest y
  memory-should-contain [
    10 <- 1  # first is correct
    11 <- 0  # rest is nil
  ]
]

## convert lambda text to a tree of cells

def parse in:text -> out:&:cell [
  local-scope
  load-ingredients
  s:&:stream:char <- new-stream in
  out, s <- parse s
  trace 2, [app/parse], out
]

def parse in:&:stream:char -> out:&:cell, in:&:stream:char [
  local-scope
  load-ingredients
  # skip whitespace
  in <- skip-whitespace in
  c:char, eof?:bool <- peek in
  return-if eof?, 0/nil
  pair?:bool <- equal c, 40/open-paren
  {
    break-if pair?
    # atom
    buf:&:buffer <- new-buffer 30
    {
      done?:bool <- end-of-stream? in
      break-if done?
      # stop before close paren or space
      c:char <- peek in
      done? <- equal c, 41/close-paren
      break-if done?
      done? <- space? c
      break-if done?
      c <- read in
      buf <- append buf, c
      loop
    }
    s:text <- buffer-to-array buf
    out <- new-atom s
  }
  {
    break-unless pair?
    # pair
    read in  # skip the open-paren
    out <- new cell:type  # start out with nil
    # read in first element of pair
    {
      end?:bool <- end-of-stream? in
      not-end?:bool <- not end?
      assert not-end?, [unbalanced '(' in expression]
      c <- peek in
      close-paren?:bool <- equal c, 41/close-paren
      break-if close-paren?
      first:&:cell, in <- parse in
      *out <- merge 1/pair, first, 0/nil
    }
    # read in any remaining elements
    curr:&:cell <- copy out
    {
      in <- skip-whitespace in
      end?:bool <- end-of-stream? in
      not-end?:bool <- not end?
      assert not-end?, [unbalanced '(' in expression]
      # termination check: ')'
      c <- peek in
      {
        close-paren?:bool <- equal c, 41/close-paren
        break-unless close-paren?
        read in  # skip ')'
        break +end-pair
      }
      # still here? read next element of pair
      next:&:cell, in <- parse in
      is-dot?:bool <- atom-match? next, [.]
      {
        break-if is-dot?
        next-curr:&:cell <- new-pair next, 0/nil
        curr <- set-rest curr, next-curr
        curr <- rest curr
      }
      {
        break-unless is-dot?
        # deal with dotted pair
        in <- skip-whitespace in
        c <- peek in
        not-close-paren?:bool <- not-equal c, 41/close-paren
        assert not-close-paren?, [')' cannot immediately follow '.']
        final:&:cell <- parse in
        curr <- set-rest curr, final
        # we're not gonna update curr, so better make sure the next iteration
        # is going to end the pair
        in <- skip-whitespace in
        c <- peek in
        close-paren?:bool <- equal c, 41/close-paren
        assert close-paren?, ['.' must be followed by exactly one expression before ')']
      }
      loop
    }
    +end-pair
  }
]

def skip-whitespace in:&:stream:char -> in:&:stream:char [
  local-scope
  load-ingredients
  {
    done?:bool <- end-of-stream? in
    return-if done?, 0/null
    c:char <- peek in
    space?:bool <- space? c
    break-unless space?
    read in  # skip
    loop
  }
]

def to-text x:&:cell -> out:text [
  local-scope
  load-ingredients
  buf:&:buffer <- new-buffer 30
  buf <- to-buffer x, buf
  out <- buffer-to-array buf
]

def to-buffer x:&:cell, buf:&:buffer -> buf:&:buffer [
  local-scope
  load-ingredients
  # base case: empty cell
  {
    break-if x
    buf <- append buf, [<>]
    return
  }
  # base case: atom
  {
    s:text, atom?:bool <- maybe-convert *x, atom:variant
    break-unless atom?
    buf <- append buf, s
    return
  }
  # recursive case: pair
  buf <- append buf, [< ]
  first:&:cell <- first x
  buf <- to-buffer first, buf
  buf <- append buf, [ | ]
  rest:&:cell <- rest x
  buf <- to-buffer rest, buf
  buf <- append buf, [ >]
]

scenario parse-single-letter-atom [
  local-scope
  s:text <- new [a]
  x:&:cell <- parse s
  s2:text, 10:bool/raw <- maybe-convert *x, atom:variant
  11:@:char/raw <- copy *s2
  memory-should-contain [
    10 <- 1  # parse result is an atom
    11:array:character <- [a]
  ]
]

scenario parse-atom [
  local-scope
  s:text <- new [abc]
  x:&:cell <- parse s
  s2:text, 10:bool/raw <- maybe-convert *x, atom:variant
  11:@:char/raw <- copy *s2
  memory-should-contain [
    10 <- 1  # parse result is an atom
    11:array:character <- [abc]
  ]
]

scenario parse-list-of-two-atoms [
  local-scope
  s:text <- new [(abc def)]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < abc | < def | <> > >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  x2:&:cell <- rest x
  s1:text, 11:bool/raw <- maybe-convert *x1, atom:variant
  12:bool/raw <- is-pair? x2
  x3:&:cell <- first x2
  s2:text, 13:bool/raw <- maybe-convert *x3, atom:variant
  14:&:cell/raw <- rest x2
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is an atom
    12 <- 1  # result.rest is a pair
    13 <- 1  # result.rest.first is an atom
    14 <- 0  # result.rest.rest is nil
    20:array:character <- [abc]  # result.first
    30:array:character <- [def]  # result.rest.first
  ]
]

scenario parse-list-with-extra-spaces [
  local-scope
  s:text <- new [ ( abc  def ) ]  # extra spaces
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < abc | < def | <> > >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  x2:&:cell <- rest x
  s1:text, 11:bool/raw <- maybe-convert *x1, atom:variant
  12:bool/raw <- is-pair? x2
  x3:&:cell <- first x2
  s2:text, 13:bool/raw <- maybe-convert *x3, atom:variant
  14:&:cell/raw <- rest x2
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is an atom
    12 <- 1  # result.rest is a pair
    13 <- 1  # result.rest.first is an atom
    14 <- 0  # result.rest.rest is nil
    20:array:character <- [abc]  # result.first
    30:array:character <- [def]  # result.rest.first
  ]
]

scenario parse-list-of-more-than-two-atoms [
  local-scope
  s:text <- new [(abc def ghi)]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < abc | < def | < ghi | <> > > >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  x2:&:cell <- rest x
  s1:text, 11:bool/raw <- maybe-convert *x1, atom:variant
  12:bool/raw <- is-pair? x2
  x3:&:cell <- first x2
  s2:text, 13:bool/raw <- maybe-convert *x3, atom:variant
  x4:&:cell <- rest x2
  14:bool/raw <- is-pair? x4
  x5:&:cell <- first x4
  s3:text, 15:bool/raw <- maybe-convert *x5, atom:variant
  16:&:cell/raw <- rest x4
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  40:@:char/raw <- copy *s3
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is an atom
    12 <- 1  # result.rest is a pair
    13 <- 1  # result.rest.first is an atom
    14 <- 1  # result.rest.rest is a pair
    15 <- 1  # result.rest.rest.first is an atom
    16 <- 0  # result.rest.rest.rest is nil
    20:array:character <- [abc]  # result.first
    30:array:character <- [def]  # result.rest.first
    40:array:character <- [ghi]  # result.rest.rest
  ]
]

scenario parse-nested-list [
  local-scope
  s:text <- new [((abc))]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < < abc | <> > | <> >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  11:bool/raw <- is-pair? x
  x2:&:cell <- first x1
  s1:text, 12:bool/raw <- maybe-convert *x2, atom:variant
  13:&:cell/raw <- rest x1
  14:&:cell/raw <- rest x
  20:@:char/raw <- copy *s1
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is a pair
    12 <- 1  # result.first.first is an atom
    13 <- 0  # result.first.rest is nil
    14 <- 0  # result.rest is nil
    20:array:character <- [abc]  # result.first.first
  ]
]

scenario parse-nested-list-2 [
  local-scope
  s:text <- new [((abc) def)]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < < abc | <> > | < def | <> > >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  11:bool/raw <- is-pair? x
  x2:&:cell <- first x1
  s1:text, 12:bool/raw <- maybe-convert *x2, atom:variant
  13:&:cell/raw <- rest x1
  x3:&:cell <- rest x
  x4:&:cell <- first x3
  s2:text, 14:bool/raw <- maybe-convert *x4, atom:variant
  15:&:cell/raw <- rest x3
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is a pair
    12 <- 1  # result.first.first is an atom
    13 <- 0  # result.first.rest is nil
    14 <- 1  # result.rest.first is an atom
    15 <- 0  # result.rest.rest is nil
    20:array:character <- [abc]  # result.first.first
    30:array:character <- [def]  # result.rest.first
  ]
]

# todo: uncomment these tests after we figure out how to continue tests after
# assertion failures
#? scenario parse-error [
#?   local-scope
#?   s:text <- new [(]
#? #?   hide-errors
#?   x:&:cell <- parse s
#? #?   show-errors
#?   trace-should-contain [
#?     error: unbalanced '(' in expression
#?   ]
#? ]
#? 
#? scenario parse-error-after-element [
#?   local-scope
#?   s:text <- new [(abc]
#? #?   hide-errors
#?   x:&:cell <- parse s
#? #?   show-errors
#?   trace-should-contain [
#?     error: unbalanced '(' in expression
#?   ]
#? ]

scenario parse-dotted-list-of-two-atoms [
  local-scope
  s:text <- new [(abc . def)]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < abc | def >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  x2:&:cell <- rest x
  s1:text, 11:bool/raw <- maybe-convert *x1, atom:variant
  s2:text, 12:bool/raw <- maybe-convert *x2, atom:variant
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  memory-should-contain [
    # parses to < abc | def >
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is an atom
    12 <- 1  # result.rest is an atom
    20:array:character <- [abc]  # result.first
    30:array:character <- [def]  # result.rest
  ]
]

scenario parse-dotted-list-of-more-than-two-atoms [
  local-scope
  s:text <- new [(abc def . ghi)]
  x:&:cell <- parse s
  trace-should-contain [
    app/parse: < abc | < def | ghi > >
  ]
  10:bool/raw <- is-pair? x
  x1:&:cell <- first x
  x2:&:cell <- rest x
  s1:text, 11:bool/raw <- maybe-convert *x1, atom:variant
  12:bool/raw <- is-pair? x2
  x3:&:cell <- first x2
  s2:text, 13:bool/raw <- maybe-convert *x3, atom:variant
  x4:&:cell <- rest x2
  s3:text, 14:bool/raw <- maybe-convert *x4, atom:variant
  20:@:char/raw <- copy *s1
  30:@:char/raw <- copy *s2
  40:@:char/raw <- copy *s3
  memory-should-contain [
    10 <- 1  # parse result is a pair
    11 <- 1  # result.first is an atom
    12 <- 1  # result.rest is a pair
    13 <- 1  # result.rest.first is an atom
    14 <- 1  # result.rest.rest is an atom
    20:array:character <- [abc]  # result.first
    30:array:character <- [def]  # result.rest.first
    40:array:character <- [ghi]  # result.rest.rest
  ]
]

## convert tree of cells to Mu text

def to-mu in:&:cell -> out:text [
  local-scope
  load-ingredients
  buf:&:buffer <- new-buffer 30
  buf <- to-mu in, buf
  out <- buffer-to-array buf
]

def to-mu in:&:cell, buf:&:buffer -> buf:&:buffer, result-name:text [
  local-scope
  load-ingredients
  # null cell? no change.
  # pair with all atoms? gensym a new variable
  # pair containing other pairs? recurse
  result-name <- copy 0
]