site/contents/reference-lang.md
1 2 3 4 5 6 7 8 9 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 |
----- content-type: "page" title: "lang Module" ----- {@ _defs_.md || 0 @} {#sig||'||quote#} {#alias||'||quote#} {#sig||:||define#} {#alias||:||define#} {#alias||::||operator#} {#sig||?||help#} {#alias||?||help#} {#sig||*||invoke#} {#sig||@||bind#} {#alias||@||bind#} {#sig||>||save-symbol#} {#sig||<||load-symbol#} {#alias||->||dequote#} {#alias||>>||prefix-dequote#} {#alias||><||infix-dequote#} {#alias||=>||apply#} {#op||==>||{{none}}||{{none}}|| Symbol used to separate input and output values in operator signatures.#} {#alias||=-=||expect-empty-stack#} {#sig||#||quote-bind#} {#alias||#||quote-bind#} {#sig||=||quote-define#} {#alias||=||quote-define#} {#op||apply||{{q}}||({{a0p}})|| Returns a new quotation obtained by evaluating each element of {{q}} in a separate stack. #} {#op||args||{{none}}||{{q}}|| Returns a list of all arguments passed to the current program.#} {#op||bind||{{any}} {{sl}}||{{none}}|| Binds the specified value (auto-quoted) to an existing symbol {{sl}}.#} {#op||bool||{{any}}||{{b}}|| > Converts {{any}} to a boolean value based on the following rules: > > * If {{any}} is a boolean value, no conversion is performed. > * If {{any}} is {{null}}, it is converted to {{f}}. > * If {{any}} is a numeric value, zero is converted to {{f}}, otherwise it is converted to {{t}}. > * If {{any}} is a quotation or a dictionary, the empty quotation or dictionary is converted to {{f}}, otherwise it is converted to {{t}}. > * If {{any}} is a string, the empty string, and `"false"` are converted to {{f}}, otherwise it is converted to {{t}}.#} {#op||case||(({{q1}} {{q2}}){{0p}})||{{a0p}}|| > This operator takes a quotation containing _n_ different conditional branches. > > Each branch must be a quotation containing two quotations, and it is processed as follows: > > * if {{q1}} evaluates to {{t}}, then the {{q2}} is executed. > * if {{q1}} evaluates to {{f}}, then the following branch is processed (if any). > > > %sidebar% > > Example > > > > The following program prints "Smaller than 3": > > > > 2 ( > > ((> 3) ("Greater than 3" put!)) > > ((< 3) ("Smaller than 3" put!)) > > ((true) ("Exactly 3" put!)) > > ) case #} {#op||compiled?||{{none}}||{{b}}|| Returns {{t}} if the current program has been compiled.#} {#op||define||{{any}} {{sl}}||{{none}}|| Defines a new symbol {{sl}}, containing the specified value (auto-quoted if not already a quotation).#} {#op||define-sigil||{{any}} {{sl}}||{{none}}|| Defines a new sigil {{sl}}, containing the specified value (auto-quoted if not already a quotation).#} {#op||defined-symbol?||{{sl}}||{{b}}|| Returns {{t}} if the symbol {{sl}} is defined, {{f}} otherwise.#} {#op||defined-sigil?||{{sl}}||{{b}}|| Returns {{t}} if the symbol {{sl}} is defined, {{f}} otherwise.#} {#op||delete-sigil||{{sl}}||{{none}}|| Deletes the specified symbol {{sl}}.#} {#op||delete-sigil||{{sl}}||{{none}}|| Deletes the specified user-defined sigil {{sl}}.#} {#op||dequote||{{q}}||{{a0p}}|| > Pushes the contents of quotation {{q}} on the stack. > > Each element is pushed on the stack one by one. If any error occurs, {{q}} is restored on the stack.#} {#op||eval||{{s}}||{{a0p}}|| Parses and interprets {{s}}. #} {#op||exit||{{i}}||{{none}}|| Exits the program or shell with {{i}} as return code. #} {#op||expect||{{q1}}||{{q2}}|| > Validates the first _n_ elements of the stack against the type descriptions specified in {{q1}} (_n_ is {{q1}}'s length) and if all the elements are valid returns them wrapped in {{q2}} (in reverse order). > > %tip% > > Tips > > > > * You can specify a typed dictionary by prepending the type name with `dict:`. Example: `dict:socket` > > * You can specify two or more matching types by separating the type names with a pipe: `string|quot` > > %sidebar% > > Example > > > > Assuming that the following elements are on the stack (from top to bottom): > > > > `1 "test" 3.4` > > > > the following program evaluates to `true`: > > > > `(int string num) expect (3.4 "test" 1) ==`#} {#op||expect-empty-stack||{{none}}||{{none}}|| Raises an error if the stack is not empty.#} {#op||float||{{any}}||{{flt}}|| > Converts {{any}} to an integer value based on the following rules: > > * If {{any}} is {{t}}, it is converted to `1.0`. > * If {{any}} is {{f}}, it is converted to `0.0`. > * If {{any}} is {{null}}, it is converted to `0.0` >. * If {{any}} is a integer, it is converted to float value. > * If {{any}} is a float, no conversion is performed. > * If {{any}} is a string, it is parsed as a float value.#} {#op||foreach||{{q1}} {{q2}}||{{a0p}}|| Applies the quotation {{q2}} to each element of {{q1}}.#} {#op||format-error||{{e}}||{{s}}|| > Formats the error {{e}} as a string. > > %sidebar% > > Example > > > > The following code: > > > > ( > > ( > > {"MyError" :error "This is a test error" :message} raise > > ) > > (format-error) > > ) try > > > > produces: `"This is a test error"`#} {#op||from-json||{{s}}||{{any}}|| Converts a JSON string into {{m}} data.#} {#op||from-yaml||{{s}}||{{any}}|| > Converts a YAML string into {{m}} data. > > %note% > > Note > > > > At present, only YAML objects containing string values are supported.#} {#op||gets||{{none}}||{{s}}|| Reads a line from STDIN and places it on top of the stack as a string.#} {#op||help||{{sl}}||{{none}}|| Prints the help text for {{sl}}, if available. #} {#op||if||{{q1}} {{q2}} {{q3}}||{{a0p}}|| If {{q1}} evaluates to {{t}} then evaluates {{q2}}, otherwise evaluates {{q3}}.#} {#op||import||{{sl}}||{{none}}|| Imports the a previously-loaded module {{sl}}, defining all its symbols in the current scope. #} {#op||infix-dequote||{{q}}||{{any}}|| > Dequotes {{q}} using infix notation. > > Note that no special operator preference is defined, symbols precedence is always left-to-right. However, you can use parentheses (quotes) to evaluate expressions before others. > > > %sidebar% > > Example > > > > The following program leaves `17` on the stack: > > > > (2 + (3 * 5)) infix-dequote > > > > while this program leaves `25` on the stack: > > > > (2 + 3 * 5) infix-dequote #} {#op||int||{{any}}||{{i}}|| > Converts {{any}} to an integer value based on the following rules: > > * If {{any}} is {{t}}, it is converted to `1`. > * If {{any}} is {{f}}, it is converted to `0`. > * If {{any}} is {{null}}, it is converted to `0`. > * If {{any}} is an integer, no conversion is performed. > * If {{any}} is a float, it is converted to an integer value by truncating its decimal part. > * If {{any}} is a string, it is parsed as an integer value.#} {#op||invoke||{{sl}}||{{a0p}}|| > Assming that {{sl}} is a formatted like *dictionary*/*symbol*, calls *symbol* defined in *dictionary* (note that this also works for nested dictionaries. > > > %sidebar% > > Example > > > > The following program leaves `100` on the stack: > > > > {{100 :b} :a} :test *test/a/b #} {#op||line-info||{{none}}||{{d}}|| Returns a dictionary {{d}} containing a **filename**, **line**, and **column** properties identifying the filename, line and column of the current symbol.#} {#op||linrec||{{q1}} {{q2}} {{q3}} {{q4}}||{{a0p}}|| > Implements linear recursions as follows: > > 1. Evaluates {{q1}}. > * If {{q1}} evaluates to {{t}}, then it evaluates {{q2}}. > * Otherwises it executes {{q3}} and recurses using the same four quotations. > 2. Finally, it executes {{q4}}. > > > %sidebar% > > Example > > > > The following program leaves `120` on the stack, the factorial of 5: > > > > 5 (dup 0 ==) 'succ (dup pred) '* linrec #} {#op||lite?||{{none}}||{{b}}|| Returns {{t}} if min was built in _lite_ mode. #} {#op||load||{{sl}}||{{a0p}}|| Parses and interprets the specified {{m}} file {{sl}}, adding [.min](class:ext) if not specified. #} {#op||load-symbol||{{sl}}||{{a0p}}|| Loads the contents of symbol {{sl}} from the [.min\_symbols](class:file) file. #} {#op||loglevel||{{sl}}||{{none}}|| > Sets the current logging level to {{sl}}. {{sl}} must be one of the following strings or quoted symbols: > > * debug > * info > * notice > * warn > * error > * fatal > > > %note% > > Note > > > > The default logging level is _notice_.#} {#op||loglevel?||{{none}}||{{s}}|| Returns the current log level (debug, info, notive, warn, error or fatal). #} {#op||operator||{{q}}||{{a0p}}|| > Provides a way to define a new operator (symbol, sigil, or typeclass) on the current scope performing additional checks (compared to `define` and `define-sigil`), and automatically mapping inputs and outputs. > > {{q}} is a quotation containing: > > * A symbol identifying the type of operator to define (`symbol`, `sigil`, or `typeclass`). > * A symbol identifying the name of the operator. > * A quotation defining the signature of the operatorm containing input and output values identified by their type and a capturing symbol, separated by the `==>` symbol. > * A quotation identifying the body of the operator. > > The main additional features offered by this way of defining operators are the following: > > * Both input and output values are checked against a type (like when using the `expect` operator *and* automatically captured in a symbol that can be referenced in the operator body quotation. > * The full signature of the operator is declared, making the resulting code easier to understand at quick glance. > * An exception is automatically raised if the operator body pollutes the stack by adding or removing elementa from the stack (besides adding the declared output values). > * It is possible to use the `return` symbol within the body quotation to immediately stop the evaluation of the body quotation and automatically push the output values on the stack. > > > %sidebar% > > Example > > > > The following program defines a `pow` operator that calculates the power of a number providing its base and exponent, and handling some NaN results using the `return` symbol: > > > > ( > > symbol pow > > (num :base int :exp ==> num :result) > > ( > > (base 0 == exp 0 == and) > > (nan @result return) > > when > > (base 1 == exp inf == and) > > (nan @result return) > > when > > (base inf == exp 0 == and) > > (nan @result return) > > when > > exp 1 - :n > > base (dup) n times (*) n times @result > > ) > > ) :: #} {#op||opts||{{none}}||{{d}}|| Returns a dictionary of all options passed to the current program, with their respective values.#} {#op||parse||{{s}}||{{q}}|| Parses {{s}} and returns a quoted program {{q}}. #} {#op||prefix-dequote||{{q}}||{{any}}|| > Dequotes {{q}} using prefix notation (essentially it reverses {{q}} and dequotes it). > > > %sidebar% > > Example > > > > The following program leaves `4` on the stack: > > > > (* 8 4) prefix-dequote #} {#op||prompt||{{none}}||{{s}}|| > This symbol is used to configure the prompt of the min shell. By default, it is set to the following quotation: > > ("[$1]$$ " (.) => %) > > Unlike other predefined symbols, this symbol is _unsealed_, which means it can be modified.#} {#op||publish||{{sl}} {{d}}||{{none}}|| > Publishes symbol {{sl}} to the scope of {{d}}. > > > %sidebar% > > Example > > > Publish symbol [my-local-symbol](class:kwd) to [ROOT](class:kwd) scope: > > `'my-local-symbol ROOT publish` #} {#op||puts||{{any}}||{{any}}|| Prints {{any}} and a new line to STDOUT.#} {#op||quit||{{none}}||{{none}}|| Exits the program or shell with 0 as return code. #} {#op||quote||{{any}}||({{any}})|| Wraps {{any}} in a quotation. #} {#op||quote-bind||{{any}} {{sl}}||{{none}}|| Quotes {{any}} and binds the quotation to the existing symbol {{sl}}. #} {#op||quote-define||{{any}} {{sl}}||{{none}}|| Quotes {{any}} and assigns the quotation to the symbol {{sl}}, creating it if not already defined. #} {#op||raise||{{e}}||{{none}}|| Raises the error specified via the dictionary {{e}}.#} {#op||raw-args||{{none}}||{{q}}|| Returns a list of all arguments and (non-parsed) options passed to the current program.#} {#op||remove-symbol||{{sl}}||{{none}}|| Removes the symbol {{sl}} from the [.min\_symbols](class:file) file. #} {#op||require||{{sl}}||{{d}}|| Parses and interprets (in a separater interpreter) the specified {{m}} file {{sl}}, adding [.min](class:ext) if not specified, and returns a module dictionary {{d}} containing all the symbols defined in {{sl}}. #} {#op||return||{{none}}||{{none}}|| If used within the body quotation of an operator definition, causes the interpreter to stop pushing further body elements on the stack and start pushing tbe operator output values on the stack. If used outside of the body quotation of an operator definition, it raises an exception.#} {#op||ROOT||{{none}}||{{d}}|| Returns a module holding a reference to the [ROOT](class:kwd) scope. > > %tip% > > Tip > > > > This symbol is very useful in conjunction with the **with** operator. #} {#op||save-symbol||{{sl}}||{{none}}|| Saves the contents of symbol {{sl}} to the [.min\_symbols](class:file) file. #} {#op||scope||{{none}}||{{d}}|| > Returns a dictionary {{d}} holding a reference to the current scope. > > This can be useful to save a reference to a given execution scope to access later on. > > > %sidebar% > > Example > > > > The following program leaves `{(2) :two ;module}` on the stack: > > > > {} :myscope (2 :two scope @myscope) -> #} {#op||saved-symbols||{{none}}||({{s0p}})|| Returns a quotation containing all symbols saved in the [.min\_symbols](class:file) file. #} {#op||scope-sigils||{{d}}||({{s0p}})|| Returns a list of all sigils defined in dictionary {{d}}.#} {#op||scope-symbols||{{d}}||({{s0p}})|| Returns a list of all symbols defined in dictionary {{d}}.#} {#op||seal-symbol||{{sl}}||{{none}}|| Seals symbol {{sl}}, so that it cannot be re-assigned. #} {#op||seal-sigil||{{sl}}||{{none}}|| Seals the user-defined sigil {{sl}}, so that it cannot be re-defined. #} {#op||sealed-symbol?||{{sl}}||{{b}}|| Returns {{t}} if the symbol {{sl}} is sealed, {{f}} otherwise.#} {#op||sealed-sigil?||{{sl}}||{{b}}|| Returns {{t}} if the sigil {{sl}} is sealed, {{f}} otherwise.#} {#op||sigil-help||{{sl}}||{{help}}|{{null}}|| Returns the help dictionary for the sigil {{sl}}, if available, {{null}} otherwise. #} {#op||sigils||{{none}}||({{s0p}})|| Returns a list of all sigils defined in the [ROOT](class:kwd) scope.#} {#op||source||{{sl}}||{{q}}|| Display the source code of symbol {{sl}} (if it has been implemented a {{m}} quotation). #} {#op||string||{{any}}||{{s}}|| Converts {{any}} to its string representation.#} {#op||symbols||{{none}}||({{s0p}})|| Returns a list of all symbols defined in the [ROOT](class:kwd) scope.#} {#op||symbol-help||{{sl}}||{{help}}|{{null}}|| Returns the help dictionary for the symbol {{sl}}, if available, {{null}} otherwise. #} {#op||tap||{{any}} {{q}}||{{any}}|| > Performs the following operations: > > 1. Removes {{any}} from the stack. > 2. For each quotation defined in {{q}} (which is a quotation of quotations each requiring one argument and returning one argument): > 1. Pushes {{any}} back to the stack. > 2. Dequotes the quotation and saves the result as {{any}}. > 3. Push the resulting {{any}} back on the stack. > > > %sidebar% > > Example > > > > The following program: > > > > {1 :a 2 :b 3 :c} ( > > (dup /a succ succ %a) > > (dup /b succ %b) > > ) tap > > > > Returns `{3 :a 3 :b 3 :c}`.#} {#op||times||{{q}} {{i}}||{{a0p}}|| Applies the quotation {{q}} {{i}} times.#} {#op||to-json||{{any}}||{{s}}|| Converts {{any}} into a JSON string.#} {#op||to-yaml||{{any}}||{{s}}|| > Converts {{any}} into a YAML string. > > > %note% > > Note > > > > At present, only {{m}} dictionaries containing string values are supported.#} {#op||try||({{q1}} {{q}}{{2}}{{01}} {{q}}{{3}}{{01}})||{{a0p}}|| > Evaluates a quotation as a try/catch/finally block. > > The must contain the following elements: > > 1. A quotation {{q1}} containing the code to be evaluated (_try_ block). > 1. _(optional)_ A quotation {{q2}} containing the code to execute in case of error (_catch_ block). > 1. _(optional)_ A quotation {{q3}} containing the code to execute after the code has been evaluated, whether an error occurred or not (_finally_ block). > > > %sidebar% > > Example > > > > The following program executed on an empty stack prints the message "Insufficient items on the stack" and pushes 0 on the stack: > > > > ( > > (pop) > > (format-error puts) > > (0) > > ) try #} {#op||unless||{{q1}} {{q2}}||{{a0p}}|| If {{1}} evaluates to {{f}} then evaluates {{2}}.#} {#op||unseal-symbol||{{sl}}||{{none}}|| Unseals the user-defined symbol {{sl}}, so that it can be re-assigned. #} {#op||unseal-sigil||{{sl}}||{{none}}|| Unseals sigil {{sl}}, so that it can be re-defined (system sigils cannot be unsealed). #} {#op||version||{{none}}||{{s}}|| Returns the current min version number. #} {#op||when||{{q1}} {{q2}}||{{a0p}}|| If {{q1}} evaluates to {{t}} then evaluates {{q2}}.#} {#op||while||{{q1}} {{q2}}||{{a0p}}|| > Executes {{q2}} while {{q1}} evaluates to {{t}}. > > > %sidebar% > > Example > > > > The following program prints all natural numbers from 0 to 10: > > > > 0 :count > > (count 10 <=) > > (count puts succ @count) while #} {#op||with||{{q1}} {{q2}}||{{a0p}}|| Pushes each item of {{q1}} on the stack using the scope of {{q2}} as scope. > > %sidebar% > > Example > > > > This operator is useful to define symbols on the [ROOT](class:kwd) scope or another scope. For example min's prelude includes the following code used to import certain modules only if min was not compiled in lite mode: > > > > 'lite? ( > > ( > > 'crypto import > > 'math import > > 'net import > > 'http import > > ) ROOT with > > ) unless #} |