From 797a46d51c80554d05edb3f64211066b0c940972 Mon Sep 17 00:00:00 2001 From: "Kartik K. Agaram" Date: Wed, 26 Nov 2014 08:30:26 -0800 Subject: 330 --- Readme.md | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 52 insertions(+), 12 deletions(-) (limited to 'Readme.md') diff --git a/Readme.md b/Readme.md index 65f250c2..ab36e9ed 100644 --- a/Readme.md +++ b/Readme.md @@ -80,26 +80,33 @@ As a sneak peek, here's how you compute factorial in mu: reply 1/literal } ; return n*factorial(n-1) - tmp1/integer <- sub n/integer 1/literal + tmp1/integer <- sub n/integer, 1/literal tmp2/integer <- factorial tmp1/integer result/integer <- mul tmp2/integer, n/integer reply result/integer ] ``` -The grammar is extremely simple. All you have are statements and blocks. -Statements are either labels or instructions of the form: +Programs are lists of instructions, each on a line, sometimes grouped with +brackets. Instructions take the form: ``` oargs <- OP args ``` Input and output args have to be simple; no sub-expressions are permitted. But -you can have any number of them. Each arg can have any number of bits of -metadata like the types above, separated by slashes. Anybody can write tools -to statically analyze or verify programs using new metadata. Or they can just -be documentation; any metadata the system doesn't recognize gets silently -ignored. +you can have any number of them. In particular, instructions can return +multiple output arguments. For example, you can perform integer division as +follows: + +``` + quotient/integer, remainder/integer <- idiv 11/literal, 3/literal +``` + +Each arg can have any number of bits of metadata like the types above, +separated by slashes. Anybody can write tools to statically analyze or verify +programs using new metadata. Or they can just be documentation; any metadata +the system doesn't recognize gets silently ignored. Try this program out now: @@ -109,11 +116,44 @@ Try this program out now: ... # ignore the memory dump for now ``` -(The code in factorial.mu looks different from the idealized syntax above. +(The code in `factorial.mu` looks different from the idealized syntax above. We'll get to an actual parser in time.) --- +An alternative way to define factorial is by including *labels*, and later +inserting code at them. + +```lisp + def factorial [ + default-scope/scope-address <- new scope/literal 30/literal + n/integer <- arg + { + base-case + } + recursive-case + ] + + after base-case [ + ; if n=0 return 1 + zero?/boolean <- eq n/integer, 0/literal + break-unless zero?/boolean + reply 1/literal + ] + + after recursive-case [ + ; return n*factorial(n-1) + tmp1/integer <- sub n/integer, 1/literal + tmp2/integer <- factorial tmp1/integer + result/integer <- mul tmp2/integer, n/integer + reply result/integer + ] +``` + +(You'll find this version in `tangle.mu`.) + +--- + Another example, this time with concurrency. ```shell @@ -164,10 +204,10 @@ Try running the tests: $ # all tests passed! ``` -Now start reading mu.arc.t to see how it works. A colorized copy of it is at -mu.arc.t.html and http://akkartik.github.io/mu. +Now start reading `mu.arc.t` to see how it works. A colorized copy of it is at +`mu.arc.t.html` and http://akkartik.github.io/mu. -You might also want to peek in the .traces directory, which automatically +You might also want to peek in the `.traces` directory, which automatically includes logs for each test showing you just how it ran on my machine. If mu eventually gets complex enough that you have trouble running examples, these logs might help figure out if my system is somehow different from yours or if -- cgit 1.4.1-2-gfad0 ef='#n10'>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