HCoop / bpt / guile.git / blame
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| 677cd590 RB |
1 | ;;;; -*-scheme-*- |
| 2 | ;;;; | |
| cd5fea8d | 3 | ;;;; Copyright (C) 2001, 2003, 2006 Free Software Foundation, Inc. |
| 86b96c16 | 4 | ;;;; |
| 73be1d9e MV |
5 | ;;;; This library is free software; you can redistribute it and/or |
| 6 | ;;;; modify it under the terms of the GNU Lesser General Public | |
| 7 | ;;;; License as published by the Free Software Foundation; either | |
| 8 | ;;;; version 2.1 of the License, or (at your option) any later version. | |
| 86b96c16 | 9 | ;;;; |
| 73be1d9e | 10 | ;;;; This library is distributed in the hope that it will be useful, |
| 86b96c16 | 11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 73be1d9e MV |
12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | ;;;; Lesser General Public License for more details. | |
| 86b96c16 | 14 | ;;;; |
| 73be1d9e MV |
15 | ;;;; You should have received a copy of the GNU Lesser General Public |
| 16 | ;;;; License along with this library; if not, write to the Free Software | |
| 92205699 | 17 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 86b96c16 MD |
18 | ;;;; |
| 19 | \f | |
| 20 | ||
| a63812a2 JB |
21 | ;;; Portable implementation of syntax-case |
| 22 | ;;; Extracted from Chez Scheme Version 5.9f | |
| 23 | ;;; Authors: R. Kent Dybvig, Oscar Waddell, Bob Hieb, Carl Bruggeman | |
| 24 | ||
| 86b96c16 MD |
25 | ;;; Modified by Mikael Djurfeldt <djurfeldt@nada.kth.se> according |
| 26 | ;;; to the ChangeLog distributed in the same directory as this file: | |
| 27 | ;;; 1997-08-19, 1997-09-03, 1997-09-10, 2000-08-13, 2000-08-24, | |
| 28 | ;;; 2000-09-12, 2001-03-08 | |
| 29 | ||
| a63812a2 JB |
30 | ;;; Copyright (c) 1992-1997 Cadence Research Systems |
| 31 | ;;; Permission to copy this software, in whole or in part, to use this | |
| 32 | ;;; software for any lawful purpose, and to redistribute this software | |
| 33 | ;;; is granted subject to the restriction that all copies made of this | |
| 34 | ;;; software must include this copyright notice in full. This software | |
| 35 | ;;; is provided AS IS, with NO WARRANTY, EITHER EXPRESS OR IMPLIED, | |
| 36 | ;;; INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY | |
| 37 | ;;; OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL THE | |
| 38 | ;;; AUTHORS BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES OF ANY | |
| 39 | ;;; NATURE WHATSOEVER. | |
| 40 | ||
| a63812a2 JB |
41 | ;;; Before attempting to port this code to a new implementation of |
| 42 | ;;; Scheme, please read the notes below carefully. | |
| 43 | ||
| 44 | ||
| 45 | ;;; This file defines the syntax-case expander, sc-expand, and a set | |
| 46 | ;;; of associated syntactic forms and procedures. Of these, the | |
| 47 | ;;; following are documented in The Scheme Programming Language, | |
| 48 | ;;; Second Edition (R. Kent Dybvig, Prentice Hall, 1996). Most are | |
| 49 | ;;; also documented in the R4RS and draft R5RS. | |
| 50 | ;;; | |
| 51 | ;;; bound-identifier=? | |
| 52 | ;;; datum->syntax-object | |
| 53 | ;;; define-syntax | |
| 54 | ;;; fluid-let-syntax | |
| 55 | ;;; free-identifier=? | |
| 56 | ;;; generate-temporaries | |
| 57 | ;;; identifier? | |
| 58 | ;;; identifier-syntax | |
| 59 | ;;; let-syntax | |
| 60 | ;;; letrec-syntax | |
| 61 | ;;; syntax | |
| 62 | ;;; syntax-case | |
| 63 | ;;; syntax-object->datum | |
| 64 | ;;; syntax-rules | |
| 65 | ;;; with-syntax | |
| 66 | ;;; | |
| 67 | ;;; All standard Scheme syntactic forms are supported by the expander | |
| 68 | ;;; or syntactic abstractions defined in this file. Only the R4RS | |
| 69 | ;;; delay is omitted, since its expansion is implementation-dependent. | |
| 70 | ||
| 71 | ;;; The remaining exports are listed below: | |
| 72 | ;;; | |
| 73 | ;;; (sc-expand datum) | |
| 74 | ;;; if datum represents a valid expression, sc-expand returns an | |
| 75 | ;;; expanded version of datum in a core language that includes no | |
| 76 | ;;; syntactic abstractions. The core language includes begin, | |
| 77 | ;;; define, if, lambda, letrec, quote, and set!. | |
| 78 | ;;; (eval-when situations expr ...) | |
| 79 | ;;; conditionally evaluates expr ... at compile-time or run-time | |
| 80 | ;;; depending upon situations (see the Chez Scheme System Manual, | |
| 81 | ;;; Revision 3, for a complete description) | |
| 82 | ;;; (syntax-error object message) | |
| 83 | ;;; used to report errors found during expansion | |
| 84 | ;;; (install-global-transformer symbol value) | |
| 85 | ;;; used by expanded code to install top-level syntactic abstractions | |
| 86 | ;;; (syntax-dispatch e p) | |
| 87 | ;;; used by expanded code to handle syntax-case matching | |
| 88 | ||
| 89 | ;;; The following nonstandard procedures must be provided by the | |
| 90 | ;;; implementation for this code to run. | |
| 91 | ;;; | |
| 92 | ;;; (void) | |
| 93 | ;;; returns the implementation's cannonical "unspecified value". This | |
| 94 | ;;; usually works: (define void (lambda () (if #f #f))). | |
| 95 | ;;; | |
| 96 | ;;; (andmap proc list1 list2 ...) | |
| 97 | ;;; returns true if proc returns true when applied to each element of list1 | |
| 98 | ;;; along with the corresponding elements of list2 .... | |
| 99 | ;;; The following definition works but does no error checking: | |
| 100 | ;;; | |
| 101 | ;;; (define andmap | |
| 102 | ;;; (lambda (f first . rest) | |
| 103 | ;;; (or (null? first) | |
| 104 | ;;; (if (null? rest) | |
| 105 | ;;; (let andmap ((first first)) | |
| 106 | ;;; (let ((x (car first)) (first (cdr first))) | |
| 107 | ;;; (if (null? first) | |
| 108 | ;;; (f x) | |
| 109 | ;;; (and (f x) (andmap first))))) | |
| 110 | ;;; (let andmap ((first first) (rest rest)) | |
| 111 | ;;; (let ((x (car first)) | |
| 112 | ;;; (xr (map car rest)) | |
| 113 | ;;; (first (cdr first)) | |
| 114 | ;;; (rest (map cdr rest))) | |
| 115 | ;;; (if (null? first) | |
| 116 | ;;; (apply f (cons x xr)) | |
| 117 | ;;; (and (apply f (cons x xr)) (andmap first rest))))))))) | |
| 118 | ;;; | |
| 119 | ;;; The following nonstandard procedures must also be provided by the | |
| 120 | ;;; implementation for this code to run using the standard portable | |
| 121 | ;;; hooks and output constructors. They are not used by expanded code, | |
| 122 | ;;; and so need be present only at expansion time. | |
| 123 | ;;; | |
| 124 | ;;; (eval x) | |
| 125 | ;;; where x is always in the form ("noexpand" expr). | |
| 126 | ;;; returns the value of expr. the "noexpand" flag is used to tell the | |
| 127 | ;;; evaluator/expander that no expansion is necessary, since expr has | |
| 128 | ;;; already been fully expanded to core forms. | |
| 129 | ;;; | |
| 130 | ;;; eval will not be invoked during the loading of psyntax.pp. After | |
| 131 | ;;; psyntax.pp has been loaded, the expansion of any macro definition, | |
| 132 | ;;; whether local or global, will result in a call to eval. If, however, | |
| 133 | ;;; sc-expand has already been registered as the expander to be used | |
| 134 | ;;; by eval, and eval accepts one argument, nothing special must be done | |
| 135 | ;;; to support the "noexpand" flag, since it is handled by sc-expand. | |
| 136 | ;;; | |
| 137 | ;;; (error who format-string why what) | |
| 138 | ;;; where who is either a symbol or #f, format-string is always "~a ~s", | |
| 139 | ;;; why is always a string, and what may be any object. error should | |
| 140 | ;;; signal an error with a message something like | |
| 141 | ;;; | |
| 142 | ;;; "error in <who>: <why> <what>" | |
| 143 | ;;; | |
| 144 | ;;; (gensym) | |
| 145 | ;;; returns a unique symbol each time it's called | |
| 146 | ;;; | |
| 147 | ;;; (putprop symbol key value) | |
| 148 | ;;; (getprop symbol key) | |
| 149 | ;;; key is always the symbol *sc-expander*; value may be any object. | |
| 150 | ;;; putprop should associate the given value with the given symbol in | |
| 151 | ;;; some way that it can be retrieved later with getprop. | |
| 152 | ||
| 153 | ;;; When porting to a new Scheme implementation, you should define the | |
| 154 | ;;; procedures listed above, load the expanded version of psyntax.ss | |
| 155 | ;;; (psyntax.pp, which should be available whereever you found | |
| 156 | ;;; psyntax.ss), and register sc-expand as the current expander (how | |
| 157 | ;;; you do this depends upon your implementation of Scheme). You may | |
| 158 | ;;; change the hooks and constructors defined toward the beginning of | |
| 159 | ;;; the code below, but to avoid bootstrapping problems, do so only | |
| 160 | ;;; after you have a working version of the expander. | |
| 161 | ||
| 162 | ;;; Chez Scheme allows the syntactic form (syntax <template>) to be | |
| 163 | ;;; abbreviated to #'<template>, just as (quote <datum>) may be | |
| 164 | ;;; abbreviated to '<datum>. The #' syntax makes programs written | |
| 165 | ;;; using syntax-case shorter and more readable and draws out the | |
| 166 | ;;; intuitive connection between syntax and quote. | |
| 167 | ||
| 168 | ;;; If you find that this code loads or runs slowly, consider | |
| 169 | ;;; switching to faster hardware or a faster implementation of | |
| 170 | ;;; Scheme. In Chez Scheme on a 200Mhz Pentium Pro, expanding, | |
| 171 | ;;; compiling (with full optimization), and loading this file takes | |
| 172 | ;;; between one and two seconds. | |
| 173 | ||
| 174 | ;;; In the expander implementation, we sometimes use syntactic abstractions | |
| 175 | ;;; when procedural abstractions would suffice. For example, we define | |
| 176 | ;;; top-wrap and top-marked? as | |
| 177 | ;;; (define-syntax top-wrap (identifier-syntax '((top)))) | |
| 178 | ;;; (define-syntax top-marked? | |
| 179 | ;;; (syntax-rules () | |
| 180 | ;;; ((_ w) (memq 'top (wrap-marks w))))) | |
| 181 | ;;; rather than | |
| 182 | ;;; (define top-wrap '((top))) | |
| 183 | ;;; (define top-marked? | |
| 184 | ;;; (lambda (w) (memq 'top (wrap-marks w)))) | |
| 185 | ;;; On ther other hand, we don't do this consistently; we define make-wrap, | |
| 186 | ;;; wrap-marks, and wrap-subst simply as | |
| 187 | ;;; (define make-wrap cons) | |
| 188 | ;;; (define wrap-marks car) | |
| 189 | ;;; (define wrap-subst cdr) | |
| 190 | ;;; In Chez Scheme, the syntactic and procedural forms of these | |
| 191 | ;;; abstractions are equivalent, since the optimizer consistently | |
| 192 | ;;; integrates constants and small procedures. Some Scheme | |
| 193 | ;;; implementations, however, may benefit from more consistent use | |
| 194 | ;;; of one form or the other. | |
| 195 | ||
| 196 | ||
| 197 | ;;; implementation information: | |
| 198 | ||
| 199 | ;;; "begin" is treated as a splicing construct at top level and at | |
| 200 | ;;; the beginning of bodies. Any sequence of expressions that would | |
| 201 | ;;; be allowed where the "begin" occurs is allowed. | |
| 202 | ||
| 203 | ;;; "let-syntax" and "letrec-syntax" are also treated as splicing | |
| 204 | ;;; constructs, in violation of the R4RS appendix and probably the R5RS | |
| 205 | ;;; when it comes out. A consequence, let-syntax and letrec-syntax do | |
| 206 | ;;; not create local contours, as do let and letrec. Although the | |
| 207 | ;;; functionality is greater as it is presently implemented, we will | |
| 208 | ;;; probably change it to conform to the R4RS/expected R5RS. | |
| 209 | ||
| 210 | ;;; Objects with no standard print syntax, including objects containing | |
| 211 | ;;; cycles and syntax object, are allowed in quoted data as long as they | |
| 212 | ;;; are contained within a syntax form or produced by datum->syntax-object. | |
| 213 | ;;; Such objects are never copied. | |
| 214 | ||
| 215 | ;;; All identifiers that don't have macro definitions and are not bound | |
| 216 | ;;; lexically are assumed to be global variables | |
| 217 | ||
| 218 | ;;; Top-level definitions of macro-introduced identifiers are allowed. | |
| 219 | ;;; This may not be appropriate for implementations in which the | |
| 220 | ;;; model is that bindings are created by definitions, as opposed to | |
| 221 | ;;; one in which initial values are assigned by definitions. | |
| 222 | ||
| 223 | ;;; Top-level variable definitions of syntax keywords is not permitted. | |
| 224 | ;;; Any solution allowing this would be kludgey and would yield | |
| 225 | ;;; surprising results in some cases. We can provide an undefine-syntax | |
| 226 | ;;; form. The questions is, should define be an implicit undefine-syntax? | |
| 227 | ;;; We've decided no for now. | |
| 228 | ||
| 229 | ;;; Identifiers and syntax objects are implemented as vectors for | |
| 230 | ;;; portability. As a result, it is possible to "forge" syntax | |
| 231 | ;;; objects. | |
| 232 | ||
| 233 | ;;; The implementation of generate-temporaries assumes that it is possible | |
| 234 | ;;; to generate globally unique symbols (gensyms). | |
| 235 | ||
| 236 | ;;; The input to sc-expand may contain "annotations" describing, e.g., the | |
| 237 | ;;; source file and character position from where each object was read if | |
| 238 | ;;; it was read from a file. These annotations are handled properly by | |
| 239 | ;;; sc-expand only if the annotation? hook (see hooks below) is implemented | |
| 240 | ;;; properly and the operators make-annotation, annotation-expression, | |
| 241 | ;;; annotation-source, annotation-stripped, and set-annotation-stripped! | |
| 242 | ;;; are supplied. If annotations are supplied, the proper annotation | |
| 243 | ;;; source is passed to the various output constructors, allowing | |
| 244 | ;;; implementations to accurately correlate source and expanded code. | |
| 245 | ;;; Contact one of the authors for details if you wish to make use of | |
| 246 | ;;; this feature. | |
| 247 | ||
| 248 | ||
| 249 | ||
| 250 | ;;; Bootstrapping: | |
| 251 | ||
| 252 | ;;; When changing syntax-object representations, it is necessary to support | |
| 253 | ;;; both old and new syntax-object representations in id-var-name. It | |
| 254 | ;;; should be sufficient to recognize old representations and treat | |
| 255 | ;;; them as not lexically bound. | |
| 256 | ||
| 257 | ||
| 258 | ||
| 259 | (let () | |
| 260 | (define-syntax define-structure | |
| 261 | (lambda (x) | |
| 262 | (define construct-name | |
| 263 | (lambda (template-identifier . args) | |
| 264 | (datum->syntax-object | |
| 265 | template-identifier | |
| 266 | (string->symbol | |
| 267 | (apply string-append | |
| 268 | (map (lambda (x) | |
| 269 | (if (string? x) | |
| 270 | x | |
| 271 | (symbol->string (syntax-object->datum x)))) | |
| 272 | args)))))) | |
| 273 | (syntax-case x () | |
| 274 | ((_ (name id1 ...)) | |
| 275 | (andmap identifier? (syntax (name id1 ...))) | |
| 276 | (with-syntax | |
| 277 | ((constructor (construct-name (syntax name) "make-" (syntax name))) | |
| 278 | (predicate (construct-name (syntax name) (syntax name) "?")) | |
| 279 | ((access ...) | |
| 280 | (map (lambda (x) (construct-name x (syntax name) "-" x)) | |
| 281 | (syntax (id1 ...)))) | |
| 282 | ((assign ...) | |
| 283 | (map (lambda (x) | |
| 284 | (construct-name x "set-" (syntax name) "-" x "!")) | |
| 285 | (syntax (id1 ...)))) | |
| 286 | (structure-length | |
| 287 | (+ (length (syntax (id1 ...))) 1)) | |
| 288 | ((index ...) | |
| 289 | (let f ((i 1) (ids (syntax (id1 ...)))) | |
| 290 | (if (null? ids) | |
| 291 | '() | |
| 292 | (cons i (f (+ i 1) (cdr ids))))))) | |
| 293 | (syntax (begin | |
| 294 | (define constructor | |
| 295 | (lambda (id1 ...) | |
| 296 | (vector 'name id1 ... ))) | |
| 297 | (define predicate | |
| 298 | (lambda (x) | |
| 299 | (and (vector? x) | |
| 300 | (= (vector-length x) structure-length) | |
| 301 | (eq? (vector-ref x 0) 'name)))) | |
| 302 | (define access | |
| 303 | (lambda (x) | |
| 304 | (vector-ref x index))) | |
| 305 | ... | |
| 306 | (define assign | |
| 307 | (lambda (x update) | |
| 308 | (vector-set! x index update))) | |
| 309 | ...))))))) | |
| 310 | ||
| 311 | (let () | |
| 312 | (define noexpand "noexpand") | |
| 313 | ||
| 314 | ;;; hooks to nonportable run-time helpers | |
| 315 | (begin | |
| 316 | (define fx+ +) | |
| 317 | (define fx- -) | |
| 318 | (define fx= =) | |
| 319 | (define fx< <) | |
| 320 | ||
| a63812a2 JB |
321 | (define top-level-eval-hook |
| 322 | (lambda (x) | |
| eaa6f703 | 323 | (eval `(,noexpand ,x) (interaction-environment)))) |
| a63812a2 JB |
324 | |
| 325 | (define local-eval-hook | |
| 326 | (lambda (x) | |
| eaa6f703 | 327 | (eval `(,noexpand ,x) (interaction-environment)))) |
| a63812a2 JB |
328 | |
| 329 | (define error-hook | |
| 330 | (lambda (who why what) | |
| 331 | (error who "~a ~s" why what))) | |
| 332 | ||
| 333 | (define-syntax gensym-hook | |
| 334 | (syntax-rules () | |
| 335 | ((_) (gensym)))) | |
| 336 | ||
| 337 | (define put-global-definition-hook | |
| 338 | (lambda (symbol binding) | |
| 339 | (putprop symbol '*sc-expander* binding))) | |
| 340 | ||
| 341 | (define get-global-definition-hook | |
| 342 | (lambda (symbol) | |
| 343 | (getprop symbol '*sc-expander*))) | |
| 344 | ) | |
| 345 | ||
| 346 | ||
| 347 | ;;; output constructors | |
| 35289f24 AW |
348 | (define (build-annotated src exp) |
| 349 | (if (and src (not (annotation? exp))) | |
| 350 | (make-annotation exp src #t) | |
| 351 | exp)) | |
| 352 | ||
| a63812a2 JB |
353 | (define-syntax build-application |
| 354 | (syntax-rules () | |
| 355 | ((_ source fun-exp arg-exps) | |
| 35289f24 | 356 | (build-annotated source `(,fun-exp . ,arg-exps))))) |
| a63812a2 JB |
357 | |
| 358 | (define-syntax build-conditional | |
| 359 | (syntax-rules () | |
| 360 | ((_ source test-exp then-exp else-exp) | |
| 35289f24 | 361 | (build-annotated source `(if ,test-exp ,then-exp ,else-exp))))) |
| a63812a2 JB |
362 | |
| 363 | (define-syntax build-lexical-reference | |
| 364 | (syntax-rules () | |
| 365 | ((_ type source var) | |
| 35289f24 | 366 | (build-annotated source var)))) |
| a63812a2 JB |
367 | |
| 368 | (define-syntax build-lexical-assignment | |
| 369 | (syntax-rules () | |
| 370 | ((_ source var exp) | |
| 35289f24 | 371 | (build-annotated source `(set! ,var ,exp))))) |
| a63812a2 JB |
372 | |
| 373 | (define-syntax build-global-reference | |
| 374 | (syntax-rules () | |
| 375 | ((_ source var) | |
| 9d80c156 | 376 | (build-annotated source (make-module-ref #f var #f))))) |
| a63812a2 JB |
377 | |
| 378 | (define-syntax build-global-assignment | |
| 379 | (syntax-rules () | |
| 380 | ((_ source var exp) | |
| 9d80c156 | 381 | (build-annotated source `(set! ,(make-module-ref #f var #f) ,exp))))) |
| a63812a2 JB |
382 | |
| 383 | (define-syntax build-global-definition | |
| 384 | (syntax-rules () | |
| 385 | ((_ source var exp) | |
| 35289f24 | 386 | (build-annotated source `(define ,var ,exp))))) |
| a63812a2 JB |
387 | |
| 388 | (define-syntax build-lambda | |
| 389 | (syntax-rules () | |
| 390 | ((_ src vars exp) | |
| 35289f24 | 391 | (build-annotated src `(lambda ,vars ,exp))))) |
| a63812a2 JB |
392 | |
| 393 | (define-syntax build-primref | |
| 394 | (syntax-rules () | |
| 35289f24 AW |
395 | ((_ src name) (build-annotated src name)) |
| 396 | ((_ src level name) (build-annotated src name)))) | |
| a63812a2 | 397 | |
| 80f225df | 398 | (define (build-data src exp) |
| 93f26b7b MD |
399 | (if (and (self-evaluating? exp) |
| 400 | (not (vector? exp))) | |
| 35289f24 AW |
401 | (build-annotated src exp) |
| 402 | (build-annotated src (list 'quote exp)))) | |
| a63812a2 JB |
403 | |
| 404 | (define build-sequence | |
| 405 | (lambda (src exps) | |
| 406 | (if (null? (cdr exps)) | |
| 35289f24 AW |
407 | (build-annotated src (car exps)) |
| 408 | (build-annotated src `(begin ,@exps))))) | |
| a63812a2 JB |
409 | |
| 410 | (define build-let | |
| 411 | (lambda (src vars val-exps body-exp) | |
| 412 | (if (null? vars) | |
| 35289f24 AW |
413 | (build-annotated src body-exp) |
| 414 | (build-annotated src `(let ,(map list vars val-exps) ,body-exp))))) | |
| a63812a2 JB |
415 | |
| 416 | (define build-named-let | |
| 417 | (lambda (src vars val-exps body-exp) | |
| 418 | (if (null? vars) | |
| 35289f24 AW |
419 | (build-annotated src body-exp) |
| 420 | (build-annotated src | |
| 421 | `(let ,(car vars) | |
| 422 | ,(map list (cdr vars) val-exps) ,body-exp))))) | |
| a63812a2 JB |
423 | |
| 424 | (define build-letrec | |
| 425 | (lambda (src vars val-exps body-exp) | |
| 426 | (if (null? vars) | |
| 35289f24 AW |
427 | (build-annotated src body-exp) |
| 428 | (build-annotated src | |
| 429 | `(letrec ,(map list vars val-exps) ,body-exp))))) | |
| a63812a2 JB |
430 | |
| 431 | (define-syntax build-lexical-var | |
| 432 | (syntax-rules () | |
| 35289f24 | 433 | ((_ src id) (build-annotated src (gensym (symbol->string id)))))) |
| a63812a2 | 434 | |
| 1641568c AW |
435 | ;; (define-structure (syntax-object expression wrap module)) |
| 436 | ||
| 437 | (define (make-syntax-object exp wrap . mod) | |
| 438 | (vector 'syntax-object exp wrap (if (null? mod) #f (car mod)))) | |
| 439 | ||
| 440 | (define (syntax-object? x) | |
| 441 | (and (vector? x) (> (vector-length x) 0) (eq? (vector-ref x 0) 'syntax-object))) | |
| 442 | ||
| 443 | (define (syntax-object-expression x) | |
| 444 | (vector-ref x 1)) | |
| 445 | (define (syntax-object-wrap x) | |
| 446 | (vector-ref x 2)) | |
| 447 | (define (syntax-object-module x) | |
| 448 | (vector-ref x 3)) | |
| 449 | (define (set-syntax-object-expression! x y) | |
| 450 | (vector-set! x 1 y)) | |
| 451 | (define (set-syntax-object-wrap! x y) | |
| 452 | (vector-set! x 2 y)) | |
| 453 | (define (set-syntax-object-module! x y) | |
| 454 | (vector-set! x 3 y)) | |
| a63812a2 JB |
455 | |
| 456 | (define-syntax unannotate | |
| 457 | (syntax-rules () | |
| 458 | ((_ x) | |
| 459 | (let ((e x)) | |
| 460 | (if (annotation? e) | |
| 461 | (annotation-expression e) | |
| 462 | e))))) | |
| 463 | ||
| 464 | (define-syntax no-source (identifier-syntax #f)) | |
| 465 | ||
| 466 | (define source-annotation | |
| 467 | (lambda (x) | |
| 468 | (cond | |
| 469 | ((annotation? x) (annotation-source x)) | |
| 470 | ((syntax-object? x) (source-annotation (syntax-object-expression x))) | |
| 471 | (else no-source)))) | |
| 472 | ||
| 473 | (define-syntax arg-check | |
| 474 | (syntax-rules () | |
| 475 | ((_ pred? e who) | |
| 476 | (let ((x e)) | |
| 477 | (if (not (pred? x)) (error-hook who "invalid argument" x)))))) | |
| 478 | ||
| 479 | ;;; compile-time environments | |
| 480 | ||
| 481 | ;;; wrap and environment comprise two level mapping. | |
| 482 | ;;; wrap : id --> label | |
| 483 | ;;; env : label --> <element> | |
| 484 | ||
| 485 | ;;; environments are represented in two parts: a lexical part and a global | |
| 486 | ;;; part. The lexical part is a simple list of associations from labels | |
| 487 | ;;; to bindings. The global part is implemented by | |
| 488 | ;;; {put,get}-global-definition-hook and associates symbols with | |
| 489 | ;;; bindings. | |
| 490 | ||
| 491 | ;;; global (assumed global variable) and displaced-lexical (see below) | |
| 492 | ;;; do not show up in any environment; instead, they are fabricated by | |
| 493 | ;;; lookup when it finds no other bindings. | |
| 494 | ||
| 495 | ;;; <environment> ::= ((<label> . <binding>)*) | |
| 496 | ||
| 497 | ;;; identifier bindings include a type and a value | |
| 498 | ||
| 499 | ;;; <binding> ::= (macro . <procedure>) macros | |
| 500 | ;;; (core . <procedure>) core forms | |
| 80f225df | 501 | ;;; (external-macro . <procedure>) external-macro |
| a63812a2 JB |
502 | ;;; (begin) begin |
| 503 | ;;; (define) define | |
| 504 | ;;; (define-syntax) define-syntax | |
| 505 | ;;; (local-syntax . rec?) let-syntax/letrec-syntax | |
| 506 | ;;; (eval-when) eval-when | |
| 507 | ;;; (syntax . (<var> . <level>)) pattern variables | |
| 508 | ;;; (global) assumed global variable | |
| 509 | ;;; (lexical . <var>) lexical variables | |
| 510 | ;;; (displaced-lexical) displaced lexicals | |
| 511 | ;;; <level> ::= <nonnegative integer> | |
| 512 | ;;; <var> ::= variable returned by build-lexical-var | |
| 513 | ||
| 514 | ;;; a macro is a user-defined syntactic-form. a core is a system-defined | |
| 515 | ;;; syntactic form. begin, define, define-syntax, and eval-when are | |
| 516 | ;;; treated specially since they are sensitive to whether the form is | |
| 517 | ;;; at top-level and (except for eval-when) can denote valid internal | |
| 518 | ;;; definitions. | |
| 519 | ||
| 520 | ;;; a pattern variable is a variable introduced by syntax-case and can | |
| 521 | ;;; be referenced only within a syntax form. | |
| 522 | ||
| 523 | ;;; any identifier for which no top-level syntax definition or local | |
| 524 | ;;; binding of any kind has been seen is assumed to be a global | |
| 525 | ;;; variable. | |
| 526 | ||
| 527 | ;;; a lexical variable is a lambda- or letrec-bound variable. | |
| 528 | ||
| 529 | ;;; a displaced-lexical identifier is a lexical identifier removed from | |
| 530 | ;;; it's scope by the return of a syntax object containing the identifier. | |
| 531 | ;;; a displaced lexical can also appear when a letrec-syntax-bound | |
| 532 | ;;; keyword is referenced on the rhs of one of the letrec-syntax clauses. | |
| 533 | ;;; a displaced lexical should never occur with properly written macros. | |
| 534 | ||
| 535 | (define-syntax make-binding | |
| 536 | (syntax-rules (quote) | |
| 537 | ((_ type value) (cons type value)) | |
| 538 | ((_ 'type) '(type)) | |
| 539 | ((_ type) (cons type '())))) | |
| 540 | (define binding-type car) | |
| 541 | (define binding-value cdr) | |
| 542 | ||
| 543 | (define-syntax null-env (identifier-syntax '())) | |
| 544 | ||
| 545 | (define extend-env | |
| 546 | (lambda (labels bindings r) | |
| 547 | (if (null? labels) | |
| 548 | r | |
| 549 | (extend-env (cdr labels) (cdr bindings) | |
| 550 | (cons (cons (car labels) (car bindings)) r))))) | |
| 551 | ||
| 552 | (define extend-var-env | |
| 553 | ; variant of extend-env that forms "lexical" binding | |
| 554 | (lambda (labels vars r) | |
| 555 | (if (null? labels) | |
| 556 | r | |
| 557 | (extend-var-env (cdr labels) (cdr vars) | |
| 558 | (cons (cons (car labels) (make-binding 'lexical (car vars))) r))))) | |
| 559 | ||
| 560 | ;;; we use a "macros only" environment in expansion of local macro | |
| 561 | ;;; definitions so that their definitions can use local macros without | |
| 562 | ;;; attempting to use other lexical identifiers. | |
| 563 | (define macros-only-env | |
| 564 | (lambda (r) | |
| 565 | (if (null? r) | |
| 566 | '() | |
| 567 | (let ((a (car r))) | |
| 568 | (if (eq? (cadr a) 'macro) | |
| 569 | (cons a (macros-only-env (cdr r))) | |
| 570 | (macros-only-env (cdr r))))))) | |
| 571 | ||
| 572 | (define lookup | |
| 573 | ; x may be a label or a symbol | |
| 574 | ; although symbols are usually global, we check the environment first | |
| 575 | ; anyway because a temporary binding may have been established by | |
| 576 | ; fluid-let-syntax | |
| 577 | (lambda (x r) | |
| 578 | (cond | |
| 579 | ((assq x r) => cdr) | |
| 580 | ((symbol? x) | |
| 581 | (or (get-global-definition-hook x) (make-binding 'global))) | |
| 582 | (else (make-binding 'displaced-lexical))))) | |
| 583 | ||
| 584 | (define global-extend | |
| 585 | (lambda (type sym val) | |
| 586 | (put-global-definition-hook sym (make-binding type val)))) | |
| 587 | ||
| 588 | ||
| 589 | ;;; Conceptually, identifiers are always syntax objects. Internally, | |
| 590 | ;;; however, the wrap is sometimes maintained separately (a source of | |
| 591 | ;;; efficiency and confusion), so that symbols are also considered | |
| 592 | ;;; identifiers by id?. Externally, they are always wrapped. | |
| 593 | ||
| 594 | (define nonsymbol-id? | |
| 595 | (lambda (x) | |
| 596 | (and (syntax-object? x) | |
| 597 | (symbol? (unannotate (syntax-object-expression x)))))) | |
| 598 | ||
| 599 | (define id? | |
| 600 | (lambda (x) | |
| 601 | (cond | |
| 602 | ((symbol? x) #t) | |
| 603 | ((syntax-object? x) (symbol? (unannotate (syntax-object-expression x)))) | |
| 604 | ((annotation? x) (symbol? (annotation-expression x))) | |
| 605 | (else #f)))) | |
| 606 | ||
| 607 | (define-syntax id-sym-name | |
| 608 | (syntax-rules () | |
| 609 | ((_ e) | |
| 610 | (let ((x e)) | |
| 611 | (unannotate (if (syntax-object? x) (syntax-object-expression x) x)))))) | |
| 612 | ||
| 613 | (define id-sym-name&marks | |
| 614 | (lambda (x w) | |
| 615 | (if (syntax-object? x) | |
| 616 | (values | |
| 617 | (unannotate (syntax-object-expression x)) | |
| 618 | (join-marks (wrap-marks w) (wrap-marks (syntax-object-wrap x)))) | |
| 619 | (values (unannotate x) (wrap-marks w))))) | |
| 620 | ||
| 621 | ;;; syntax object wraps | |
| 622 | ||
| 623 | ;;; <wrap> ::= ((<mark> ...) . (<subst> ...)) | |
| 624 | ;;; <subst> ::= <shift> | <subs> | |
| 625 | ;;; <subs> ::= #(<old name> <label> (<mark> ...)) | |
| 626 | ;;; <shift> ::= positive fixnum | |
| 627 | ||
| 628 | (define make-wrap cons) | |
| 629 | (define wrap-marks car) | |
| 630 | (define wrap-subst cdr) | |
| 631 | ||
| 632 | (define-syntax subst-rename? (identifier-syntax vector?)) | |
| 633 | (define-syntax rename-old (syntax-rules () ((_ x) (vector-ref x 0)))) | |
| 634 | (define-syntax rename-new (syntax-rules () ((_ x) (vector-ref x 1)))) | |
| 635 | (define-syntax rename-marks (syntax-rules () ((_ x) (vector-ref x 2)))) | |
| 636 | (define-syntax make-rename | |
| 637 | (syntax-rules () | |
| 638 | ((_ old new marks) (vector old new marks)))) | |
| 639 | ||
| 640 | ;;; labels must be comparable with "eq?" and distinct from symbols. | |
| 641 | (define gen-label | |
| 642 | (lambda () (string #\i))) | |
| 643 | ||
| 644 | (define gen-labels | |
| 645 | (lambda (ls) | |
| 646 | (if (null? ls) | |
| 647 | '() | |
| 648 | (cons (gen-label) (gen-labels (cdr ls)))))) | |
| 649 | ||
| 650 | (define-structure (ribcage symnames marks labels)) | |
| 651 | ||
| 652 | (define-syntax empty-wrap (identifier-syntax '(()))) | |
| 653 | ||
| 654 | (define-syntax top-wrap (identifier-syntax '((top)))) | |
| 655 | ||
| 656 | (define-syntax top-marked? | |
| 657 | (syntax-rules () | |
| 658 | ((_ w) (memq 'top (wrap-marks w))))) | |
| 659 | ||
| 660 | ;;; Marks must be comparable with "eq?" and distinct from pairs and | |
| 661 | ;;; the symbol top. We do not use integers so that marks will remain | |
| 662 | ;;; unique even across file compiles. | |
| 663 | ||
| 664 | (define-syntax the-anti-mark (identifier-syntax #f)) | |
| 665 | ||
| 666 | (define anti-mark | |
| 667 | (lambda (w) | |
| 668 | (make-wrap (cons the-anti-mark (wrap-marks w)) | |
| 669 | (cons 'shift (wrap-subst w))))) | |
| 670 | ||
| 671 | (define-syntax new-mark | |
| 672 | (syntax-rules () | |
| 673 | ((_) (string #\m)))) | |
| 674 | ||
| 675 | ;;; make-empty-ribcage and extend-ribcage maintain list-based ribcages for | |
| 676 | ;;; internal definitions, in which the ribcages are built incrementally | |
| 677 | (define-syntax make-empty-ribcage | |
| 678 | (syntax-rules () | |
| 679 | ((_) (make-ribcage '() '() '())))) | |
| 680 | ||
| 681 | (define extend-ribcage! | |
| 682 | ; must receive ids with complete wraps | |
| 683 | (lambda (ribcage id label) | |
| 684 | (set-ribcage-symnames! ribcage | |
| 685 | (cons (unannotate (syntax-object-expression id)) | |
| 686 | (ribcage-symnames ribcage))) | |
| 687 | (set-ribcage-marks! ribcage | |
| 688 | (cons (wrap-marks (syntax-object-wrap id)) | |
| 689 | (ribcage-marks ribcage))) | |
| 690 | (set-ribcage-labels! ribcage | |
| 691 | (cons label (ribcage-labels ribcage))))) | |
| 692 | ||
| 693 | ;;; make-binding-wrap creates vector-based ribcages | |
| 694 | (define make-binding-wrap | |
| 695 | (lambda (ids labels w) | |
| 696 | (if (null? ids) | |
| 697 | w | |
| 698 | (make-wrap | |
| 699 | (wrap-marks w) | |
| 700 | (cons | |
| 701 | (let ((labelvec (list->vector labels))) | |
| 702 | (let ((n (vector-length labelvec))) | |
| 703 | (let ((symnamevec (make-vector n)) (marksvec (make-vector n))) | |
| 704 | (let f ((ids ids) (i 0)) | |
| 705 | (if (not (null? ids)) | |
| 706 | (call-with-values | |
| 707 | (lambda () (id-sym-name&marks (car ids) w)) | |
| 708 | (lambda (symname marks) | |
| 709 | (vector-set! symnamevec i symname) | |
| 710 | (vector-set! marksvec i marks) | |
| 711 | (f (cdr ids) (fx+ i 1)))))) | |
| 712 | (make-ribcage symnamevec marksvec labelvec)))) | |
| 713 | (wrap-subst w)))))) | |
| 714 | ||
| 715 | (define smart-append | |
| 716 | (lambda (m1 m2) | |
| 717 | (if (null? m2) | |
| 718 | m1 | |
| 719 | (append m1 m2)))) | |
| 720 | ||
| 721 | (define join-wraps | |
| 722 | (lambda (w1 w2) | |
| 723 | (let ((m1 (wrap-marks w1)) (s1 (wrap-subst w1))) | |
| 724 | (if (null? m1) | |
| 725 | (if (null? s1) | |
| 726 | w2 | |
| 727 | (make-wrap | |
| 728 | (wrap-marks w2) | |
| 729 | (smart-append s1 (wrap-subst w2)))) | |
| 730 | (make-wrap | |
| 731 | (smart-append m1 (wrap-marks w2)) | |
| 732 | (smart-append s1 (wrap-subst w2))))))) | |
| 733 | ||
| 734 | (define join-marks | |
| 735 | (lambda (m1 m2) | |
| 736 | (smart-append m1 m2))) | |
| 737 | ||
| 738 | (define same-marks? | |
| 739 | (lambda (x y) | |
| 740 | (or (eq? x y) | |
| 741 | (and (not (null? x)) | |
| 742 | (not (null? y)) | |
| 743 | (eq? (car x) (car y)) | |
| 744 | (same-marks? (cdr x) (cdr y)))))) | |
| 745 | ||
| 746 | (define id-var-name | |
| 747 | (lambda (id w) | |
| 748 | (define-syntax first | |
| 749 | (syntax-rules () | |
| 750 | ((_ e) (call-with-values (lambda () e) (lambda (x . ignore) x))))) | |
| 751 | (define search | |
| 752 | (lambda (sym subst marks) | |
| 753 | (if (null? subst) | |
| 754 | (values #f marks) | |
| 755 | (let ((fst (car subst))) | |
| 756 | (if (eq? fst 'shift) | |
| 757 | (search sym (cdr subst) (cdr marks)) | |
| 758 | (let ((symnames (ribcage-symnames fst))) | |
| 759 | (if (vector? symnames) | |
| 760 | (search-vector-rib sym subst marks symnames fst) | |
| 761 | (search-list-rib sym subst marks symnames fst)))))))) | |
| 762 | (define search-list-rib | |
| 763 | (lambda (sym subst marks symnames ribcage) | |
| 764 | (let f ((symnames symnames) (i 0)) | |
| 765 | (cond | |
| 766 | ((null? symnames) (search sym (cdr subst) marks)) | |
| 767 | ((and (eq? (car symnames) sym) | |
| 768 | (same-marks? marks (list-ref (ribcage-marks ribcage) i))) | |
| 769 | (values (list-ref (ribcage-labels ribcage) i) marks)) | |
| 770 | (else (f (cdr symnames) (fx+ i 1))))))) | |
| 771 | (define search-vector-rib | |
| 772 | (lambda (sym subst marks symnames ribcage) | |
| 773 | (let ((n (vector-length symnames))) | |
| 774 | (let f ((i 0)) | |
| 775 | (cond | |
| 776 | ((fx= i n) (search sym (cdr subst) marks)) | |
| 777 | ((and (eq? (vector-ref symnames i) sym) | |
| 778 | (same-marks? marks (vector-ref (ribcage-marks ribcage) i))) | |
| 779 | (values (vector-ref (ribcage-labels ribcage) i) marks)) | |
| 780 | (else (f (fx+ i 1)))))))) | |
| 781 | (cond | |
| 782 | ((symbol? id) | |
| 783 | (or (first (search id (wrap-subst w) (wrap-marks w))) id)) | |
| 784 | ((syntax-object? id) | |
| 785 | (let ((id (unannotate (syntax-object-expression id))) | |
| 786 | (w1 (syntax-object-wrap id))) | |
| 787 | (let ((marks (join-marks (wrap-marks w) (wrap-marks w1)))) | |
| 788 | (call-with-values (lambda () (search id (wrap-subst w) marks)) | |
| 789 | (lambda (new-id marks) | |
| 790 | (or new-id | |
| 791 | (first (search id (wrap-subst w1) marks)) | |
| 792 | id)))))) | |
| 793 | ((annotation? id) | |
| 794 | (let ((id (unannotate id))) | |
| 795 | (or (first (search id (wrap-subst w) (wrap-marks w))) id))) | |
| 796 | (else (error-hook 'id-var-name "invalid id" id))))) | |
| 797 | ||
| 798 | ;;; free-id=? must be passed fully wrapped ids since (free-id=? x y) | |
| 799 | ;;; may be true even if (free-id=? (wrap x w) (wrap y w)) is not. | |
| 800 | ||
| 801 | (define free-id=? | |
| 802 | (lambda (i j) | |
| 803 | (and (eq? (id-sym-name i) (id-sym-name j)) ; accelerator | |
| 804 | (eq? (id-var-name i empty-wrap) (id-var-name j empty-wrap))))) | |
| 805 | ||
| 806 | ;;; bound-id=? may be passed unwrapped (or partially wrapped) ids as | |
| 807 | ;;; long as the missing portion of the wrap is common to both of the ids | |
| 808 | ;;; since (bound-id=? x y) iff (bound-id=? (wrap x w) (wrap y w)) | |
| 809 | ||
| 810 | (define bound-id=? | |
| 811 | (lambda (i j) | |
| 812 | (if (and (syntax-object? i) (syntax-object? j)) | |
| 813 | (and (eq? (unannotate (syntax-object-expression i)) | |
| 814 | (unannotate (syntax-object-expression j))) | |
| 815 | (same-marks? (wrap-marks (syntax-object-wrap i)) | |
| 816 | (wrap-marks (syntax-object-wrap j)))) | |
| 817 | (eq? (unannotate i) (unannotate j))))) | |
| 818 | ||
| 819 | ;;; "valid-bound-ids?" returns #t if it receives a list of distinct ids. | |
| 820 | ;;; valid-bound-ids? may be passed unwrapped (or partially wrapped) ids | |
| 821 | ;;; as long as the missing portion of the wrap is common to all of the | |
| 822 | ;;; ids. | |
| 823 | ||
| 824 | (define valid-bound-ids? | |
| 825 | (lambda (ids) | |
| 826 | (and (let all-ids? ((ids ids)) | |
| 827 | (or (null? ids) | |
| 828 | (and (id? (car ids)) | |
| 829 | (all-ids? (cdr ids))))) | |
| 830 | (distinct-bound-ids? ids)))) | |
| 831 | ||
| 832 | ;;; distinct-bound-ids? expects a list of ids and returns #t if there are | |
| 833 | ;;; no duplicates. It is quadratic on the length of the id list; long | |
| 834 | ;;; lists could be sorted to make it more efficient. distinct-bound-ids? | |
| 835 | ;;; may be passed unwrapped (or partially wrapped) ids as long as the | |
| 836 | ;;; missing portion of the wrap is common to all of the ids. | |
| 837 | ||
| 838 | (define distinct-bound-ids? | |
| 839 | (lambda (ids) | |
| 840 | (let distinct? ((ids ids)) | |
| 841 | (or (null? ids) | |
| 842 | (and (not (bound-id-member? (car ids) (cdr ids))) | |
| 843 | (distinct? (cdr ids))))))) | |
| 844 | ||
| 845 | (define bound-id-member? | |
| 846 | (lambda (x list) | |
| 847 | (and (not (null? list)) | |
| 848 | (or (bound-id=? x (car list)) | |
| 849 | (bound-id-member? x (cdr list)))))) | |
| 850 | ||
| 851 | ;;; wrapping expressions and identifiers | |
| 852 | ||
| 853 | (define wrap | |
| 854 | (lambda (x w) | |
| 855 | (cond | |
| 856 | ((and (null? (wrap-marks w)) (null? (wrap-subst w))) x) | |
| 857 | ((syntax-object? x) | |
| 858 | (make-syntax-object | |
| 859 | (syntax-object-expression x) | |
| 860 | (join-wraps w (syntax-object-wrap x)))) | |
| 861 | ((null? x) x) | |
| 862 | (else (make-syntax-object x w))))) | |
| 863 | ||
| 864 | (define source-wrap | |
| 865 | (lambda (x w s) | |
| 866 | (wrap (if s (make-annotation x s #f) x) w))) | |
| 867 | ||
| 868 | ;;; expanding | |
| 869 | ||
| 870 | (define chi-sequence | |
| 871 | (lambda (body r w s) | |
| 872 | (build-sequence s | |
| 873 | (let dobody ((body body) (r r) (w w)) | |
| 874 | (if (null? body) | |
| 875 | '() | |
| 876 | (let ((first (chi (car body) r w))) | |
| 877 | (cons first (dobody (cdr body) r w)))))))) | |
| 878 | ||
| 879 | (define chi-top-sequence | |
| 880 | (lambda (body r w s m esew) | |
| 881 | (build-sequence s | |
| 882 | (let dobody ((body body) (r r) (w w) (m m) (esew esew)) | |
| 883 | (if (null? body) | |
| 884 | '() | |
| 885 | (let ((first (chi-top (car body) r w m esew))) | |
| 886 | (cons first (dobody (cdr body) r w m esew)))))))) | |
| 887 | ||
| 888 | (define chi-install-global | |
| 889 | (lambda (name e) | |
| 890 | (build-application no-source | |
| 891 | (build-primref no-source 'install-global-transformer) | |
| 892 | (list (build-data no-source name) e)))) | |
| 893 | ||
| 894 | (define chi-when-list | |
| 895 | (lambda (e when-list w) | |
| 896 | ; when-list is syntax'd version of list of situations | |
| 897 | (let f ((when-list when-list) (situations '())) | |
| 898 | (if (null? when-list) | |
| 899 | situations | |
| 900 | (f (cdr when-list) | |
| 901 | (cons (let ((x (car when-list))) | |
| 902 | (cond | |
| 903 | ((free-id=? x (syntax compile)) 'compile) | |
| 904 | ((free-id=? x (syntax load)) 'load) | |
| 905 | ((free-id=? x (syntax eval)) 'eval) | |
| 906 | (else (syntax-error (wrap x w) | |
| 907 | "invalid eval-when situation")))) | |
| 908 | situations)))))) | |
| 909 | ||
| 910 | ;;; syntax-type returns five values: type, value, e, w, and s. The first | |
| 911 | ;;; two are described in the table below. | |
| 912 | ;;; | |
| 913 | ;;; type value explanation | |
| 914 | ;;; ------------------------------------------------------------------- | |
| 915 | ;;; core procedure core form (including singleton) | |
| 80f225df | 916 | ;;; external-macro procedure external macro |
| a63812a2 JB |
917 | ;;; lexical name lexical variable reference |
| 918 | ;;; global name global variable reference | |
| 919 | ;;; begin none begin keyword | |
| 920 | ;;; define none define keyword | |
| 921 | ;;; define-syntax none define-syntax keyword | |
| 922 | ;;; local-syntax rec? letrec-syntax/let-syntax keyword | |
| 923 | ;;; eval-when none eval-when keyword | |
| 924 | ;;; syntax level pattern variable | |
| 925 | ;;; displaced-lexical none displaced lexical identifier | |
| 926 | ;;; lexical-call name call to lexical variable | |
| 927 | ;;; global-call name call to global variable | |
| 928 | ;;; call none any other call | |
| 929 | ;;; begin-form none begin expression | |
| 930 | ;;; define-form id variable definition | |
| 931 | ;;; define-syntax-form id syntax definition | |
| 932 | ;;; local-syntax-form rec? syntax definition | |
| 933 | ;;; eval-when-form none eval-when form | |
| 934 | ;;; constant none self-evaluating datum | |
| 935 | ;;; other none anything else | |
| 936 | ;;; | |
| 937 | ;;; For define-form and define-syntax-form, e is the rhs expression. | |
| 938 | ;;; For all others, e is the entire form. w is the wrap for e. | |
| 939 | ;;; s is the source for the entire form. | |
| 940 | ;;; | |
| 941 | ;;; syntax-type expands macros and unwraps as necessary to get to | |
| 942 | ;;; one of the forms above. It also parses define and define-syntax | |
| 943 | ;;; forms, although perhaps this should be done by the consumer. | |
| 944 | ||
| 945 | (define syntax-type | |
| 946 | (lambda (e r w s rib) | |
| 947 | (cond | |
| 948 | ((symbol? e) | |
| 949 | (let* ((n (id-var-name e w)) | |
| 950 | (b (lookup n r)) | |
| 951 | (type (binding-type b))) | |
| 952 | (case type | |
| 953 | ((lexical) (values type (binding-value b) e w s)) | |
| 954 | ((global) (values type n e w s)) | |
| 955 | ((macro) | |
| 956 | (syntax-type (chi-macro (binding-value b) e r w rib) r empty-wrap s rib)) | |
| 957 | (else (values type (binding-value b) e w s))))) | |
| 958 | ((pair? e) | |
| 959 | (let ((first (car e))) | |
| 960 | (if (id? first) | |
| 961 | (let* ((n (id-var-name first w)) | |
| 962 | (b (lookup n r)) | |
| 963 | (type (binding-type b))) | |
| 964 | (case type | |
| 965 | ((lexical) (values 'lexical-call (binding-value b) e w s)) | |
| 966 | ((global) (values 'global-call n e w s)) | |
| 967 | ((macro) | |
| 968 | (syntax-type (chi-macro (binding-value b) e r w rib) | |
| 969 | r empty-wrap s rib)) | |
| 80f225df | 970 | ((core external-macro) (values type (binding-value b) e w s)) |
| a63812a2 JB |
971 | ((local-syntax) |
| 972 | (values 'local-syntax-form (binding-value b) e w s)) | |
| 973 | ((begin) (values 'begin-form #f e w s)) | |
| 974 | ((eval-when) (values 'eval-when-form #f e w s)) | |
| 975 | ((define) | |
| 976 | (syntax-case e () | |
| 977 | ((_ name val) | |
| 978 | (id? (syntax name)) | |
| 979 | (values 'define-form (syntax name) (syntax val) w s)) | |
| 980 | ((_ (name . args) e1 e2 ...) | |
| 981 | (and (id? (syntax name)) | |
| 982 | (valid-bound-ids? (lambda-var-list (syntax args)))) | |
| 983 | ; need lambda here... | |
| 984 | (values 'define-form (wrap (syntax name) w) | |
| 985 | (cons (syntax lambda) (wrap (syntax (args e1 e2 ...)) w)) | |
| 986 | empty-wrap s)) | |
| 987 | ((_ name) | |
| 988 | (id? (syntax name)) | |
| 989 | (values 'define-form (wrap (syntax name) w) | |
| 990 | (syntax (void)) | |
| 991 | empty-wrap s)))) | |
| 992 | ((define-syntax) | |
| 993 | (syntax-case e () | |
| 994 | ((_ name val) | |
| 995 | (id? (syntax name)) | |
| 996 | (values 'define-syntax-form (syntax name) | |
| 997 | (syntax val) w s)))) | |
| 998 | (else (values 'call #f e w s)))) | |
| 999 | (values 'call #f e w s)))) | |
| 1000 | ((syntax-object? e) | |
| 1001 | ;; s can't be valid source if we've unwrapped | |
| 1002 | (syntax-type (syntax-object-expression e) | |
| 1003 | r | |
| 1004 | (join-wraps w (syntax-object-wrap e)) | |
| 1005 | no-source rib)) | |
| 1006 | ((annotation? e) | |
| 1007 | (syntax-type (annotation-expression e) r w (annotation-source e) rib)) | |
| 1008 | ((self-evaluating? e) (values 'constant #f e w s)) | |
| 1009 | (else (values 'other #f e w s))))) | |
| 1010 | ||
| 1011 | (define chi-top | |
| 1012 | (lambda (e r w m esew) | |
| 1013 | (define-syntax eval-if-c&e | |
| 1014 | (syntax-rules () | |
| 1015 | ((_ m e) | |
| 1016 | (let ((x e)) | |
| 1017 | (if (eq? m 'c&e) (top-level-eval-hook x)) | |
| 1018 | x)))) | |
| 1019 | (call-with-values | |
| 1020 | (lambda () (syntax-type e r w no-source #f)) | |
| 1021 | (lambda (type value e w s) | |
| 1022 | (case type | |
| 1023 | ((begin-form) | |
| 1024 | (syntax-case e () | |
| 1025 | ((_) (chi-void)) | |
| 1026 | ((_ e1 e2 ...) | |
| 1027 | (chi-top-sequence (syntax (e1 e2 ...)) r w s m esew)))) | |
| 1028 | ((local-syntax-form) | |
| 1029 | (chi-local-syntax value e r w s | |
| 1030 | (lambda (body r w s) | |
| 1031 | (chi-top-sequence body r w s m esew)))) | |
| 1032 | ((eval-when-form) | |
| 1033 | (syntax-case e () | |
| 1034 | ((_ (x ...) e1 e2 ...) | |
| 1035 | (let ((when-list (chi-when-list e (syntax (x ...)) w)) | |
| 1036 | (body (syntax (e1 e2 ...)))) | |
| 1037 | (cond | |
| 1038 | ((eq? m 'e) | |
| 1039 | (if (memq 'eval when-list) | |
| 1040 | (chi-top-sequence body r w s 'e '(eval)) | |
| 1041 | (chi-void))) | |
| 1042 | ((memq 'load when-list) | |
| 1043 | (if (or (memq 'compile when-list) | |
| 1044 | (and (eq? m 'c&e) (memq 'eval when-list))) | |
| 1045 | (chi-top-sequence body r w s 'c&e '(compile load)) | |
| 1046 | (if (memq m '(c c&e)) | |
| 1047 | (chi-top-sequence body r w s 'c '(load)) | |
| 1048 | (chi-void)))) | |
| 1049 | ((or (memq 'compile when-list) | |
| 1050 | (and (eq? m 'c&e) (memq 'eval when-list))) | |
| 1051 | (top-level-eval-hook | |
| 1052 | (chi-top-sequence body r w s 'e '(eval))) | |
| 1053 | (chi-void)) | |
| 1054 | (else (chi-void))))))) | |
| 1055 | ((define-syntax-form) | |
| 1056 | (let ((n (id-var-name value w)) (r (macros-only-env r))) | |
| 1057 | (case m | |
| 1058 | ((c) | |
| 1059 | (if (memq 'compile esew) | |
| 1060 | (let ((e (chi-install-global n (chi e r w)))) | |
| 1061 | (top-level-eval-hook e) | |
| 1062 | (if (memq 'load esew) e (chi-void))) | |
| 1063 | (if (memq 'load esew) | |
| 1064 | (chi-install-global n (chi e r w)) | |
| 1065 | (chi-void)))) | |
| 1066 | ((c&e) | |
| 1067 | (let ((e (chi-install-global n (chi e r w)))) | |
| 1068 | (top-level-eval-hook e) | |
| 1069 | e)) | |
| 1070 | (else | |
| 1071 | (if (memq 'eval esew) | |
| 1072 | (top-level-eval-hook | |
| 1073 | (chi-install-global n (chi e r w)))) | |
| 1074 | (chi-void))))) | |
| 1075 | ((define-form) | |
| 80f225df MD |
1076 | (let* ((n (id-var-name value w)) |
| 1077 | (type (binding-type (lookup n r)))) | |
| 1078 | (case type | |
| a63812a2 JB |
1079 | ((global) |
| 1080 | (eval-if-c&e m | |
| 1081 | (build-global-definition s n (chi e r w)))) | |
| 1082 | ((displaced-lexical) | |
| 1083 | (syntax-error (wrap value w) "identifier out of context")) | |
| 80f225df MD |
1084 | (else |
| 1085 | (if (eq? type 'external-macro) | |
| 1086 | (eval-if-c&e m | |
| 1087 | (build-global-definition s n (chi e r w))) | |
| 1088 | (syntax-error (wrap value w) | |
| 1089 | "cannot define keyword at top level")))))) | |
| a63812a2 JB |
1090 | (else (eval-if-c&e m (chi-expr type value e r w s)))))))) |
| 1091 | ||
| 1092 | (define chi | |
| 1093 | (lambda (e r w) | |
| 1094 | (call-with-values | |
| 1095 | (lambda () (syntax-type e r w no-source #f)) | |
| 1096 | (lambda (type value e w s) | |
| 1097 | (chi-expr type value e r w s))))) | |
| 1098 | ||
| 1099 | (define chi-expr | |
| 1100 | (lambda (type value e r w s) | |
| 1101 | (case type | |
| 1102 | ((lexical) | |
| 1103 | (build-lexical-reference 'value s value)) | |
| 80f225df | 1104 | ((core external-macro) (value e r w s)) |
| a63812a2 JB |
1105 | ((lexical-call) |
| 1106 | (chi-application | |
| 1107 | (build-lexical-reference 'fun (source-annotation (car e)) value) | |
| 1108 | e r w s)) | |
| 1109 | ((global-call) | |
| 1110 | (chi-application | |
| 1111 | (build-global-reference (source-annotation (car e)) value) | |
| 1112 | e r w s)) | |
| 1113 | ((constant) (build-data s (strip (source-wrap e w s) empty-wrap))) | |
| 1114 | ((global) (build-global-reference s value)) | |
| 1115 | ((call) (chi-application (chi (car e) r w) e r w s)) | |
| 1116 | ((begin-form) | |
| 1117 | (syntax-case e () | |
| 1118 | ((_ e1 e2 ...) (chi-sequence (syntax (e1 e2 ...)) r w s)))) | |
| 1119 | ((local-syntax-form) | |
| 1120 | (chi-local-syntax value e r w s chi-sequence)) | |
| 1121 | ((eval-when-form) | |
| 1122 | (syntax-case e () | |
| 1123 | ((_ (x ...) e1 e2 ...) | |
| 1124 | (let ((when-list (chi-when-list e (syntax (x ...)) w))) | |
| 1125 | (if (memq 'eval when-list) | |
| 1126 | (chi-sequence (syntax (e1 e2 ...)) r w s) | |
| 1127 | (chi-void)))))) | |
| 1128 | ((define-form define-syntax-form) | |
| 1129 | (syntax-error (wrap value w) "invalid context for definition of")) | |
| 1130 | ((syntax) | |
| 1131 | (syntax-error (source-wrap e w s) | |
| 1132 | "reference to pattern variable outside syntax form")) | |
| 1133 | ((displaced-lexical) | |
| 1134 | (syntax-error (source-wrap e w s) | |
| 1135 | "reference to identifier outside its scope")) | |
| 1136 | (else (syntax-error (source-wrap e w s)))))) | |
| 1137 | ||
| 1138 | (define chi-application | |
| 1139 | (lambda (x e r w s) | |
| 1140 | (syntax-case e () | |
| 1141 | ((e0 e1 ...) | |
| 1142 | (build-application s x | |
| 1143 | (map (lambda (e) (chi e r w)) (syntax (e1 ...)))))))) | |
| 1144 | ||
| 1145 | (define chi-macro | |
| 1146 | (lambda (p e r w rib) | |
| 1147 | (define rebuild-macro-output | |
| 1148 | (lambda (x m) | |
| 1149 | (cond ((pair? x) | |
| 1150 | (cons (rebuild-macro-output (car x) m) | |
| 1151 | (rebuild-macro-output (cdr x) m))) | |
| 1152 | ((syntax-object? x) | |
| 1153 | (let ((w (syntax-object-wrap x))) | |
| 1154 | (let ((ms (wrap-marks w)) (s (wrap-subst w))) | |
| 1155 | (make-syntax-object (syntax-object-expression x) | |
| 1156 | (if (and (pair? ms) (eq? (car ms) the-anti-mark)) | |
| 1157 | (make-wrap (cdr ms) | |
| 1158 | (if rib (cons rib (cdr s)) (cdr s))) | |
| 1159 | (make-wrap (cons m ms) | |
| 1160 | (if rib | |
| 1161 | (cons rib (cons 'shift s)) | |
| 1162 | (cons 'shift s)))))))) | |
| 1163 | ((vector? x) | |
| 1164 | (let* ((n (vector-length x)) (v (make-vector n))) | |
| 1165 | (do ((i 0 (fx+ i 1))) | |
| 1166 | ((fx= i n) v) | |
| 1167 | (vector-set! v i | |
| 1168 | (rebuild-macro-output (vector-ref x i) m))))) | |
| 1169 | ((symbol? x) | |
| 1170 | (syntax-error x "encountered raw symbol in macro output")) | |
| 1171 | (else x)))) | |
| 1172 | (rebuild-macro-output (p (wrap e (anti-mark w))) (new-mark)))) | |
| 1173 | ||
| 1174 | (define chi-body | |
| 1175 | ;; In processing the forms of the body, we create a new, empty wrap. | |
| 1176 | ;; This wrap is augmented (destructively) each time we discover that | |
| 1177 | ;; the next form is a definition. This is done: | |
| 1178 | ;; | |
| 1179 | ;; (1) to allow the first nondefinition form to be a call to | |
| 1180 | ;; one of the defined ids even if the id previously denoted a | |
| 1181 | ;; definition keyword or keyword for a macro expanding into a | |
| 1182 | ;; definition; | |
| 1183 | ;; (2) to prevent subsequent definition forms (but unfortunately | |
| 1184 | ;; not earlier ones) and the first nondefinition form from | |
| 1185 | ;; confusing one of the bound identifiers for an auxiliary | |
| 1186 | ;; keyword; and | |
| 1187 | ;; (3) so that we do not need to restart the expansion of the | |
| 1188 | ;; first nondefinition form, which is problematic anyway | |
| 1189 | ;; since it might be the first element of a begin that we | |
| 1190 | ;; have just spliced into the body (meaning if we restarted, | |
| 1191 | ;; we'd really need to restart with the begin or the macro | |
| 1192 | ;; call that expanded into the begin, and we'd have to give | |
| 1193 | ;; up allowing (begin <defn>+ <expr>+), which is itself | |
| 1194 | ;; problematic since we don't know if a begin contains only | |
| 1195 | ;; definitions until we've expanded it). | |
| 1196 | ;; | |
| 1197 | ;; Before processing the body, we also create a new environment | |
| 1198 | ;; containing a placeholder for the bindings we will add later and | |
| 1199 | ;; associate this environment with each form. In processing a | |
| 1200 | ;; let-syntax or letrec-syntax, the associated environment may be | |
| 1201 | ;; augmented with local keyword bindings, so the environment may | |
| 1202 | ;; be different for different forms in the body. Once we have | |
| 1203 | ;; gathered up all of the definitions, we evaluate the transformer | |
| 1204 | ;; expressions and splice into r at the placeholder the new variable | |
| 1205 | ;; and keyword bindings. This allows let-syntax or letrec-syntax | |
| 1206 | ;; forms local to a portion or all of the body to shadow the | |
| 1207 | ;; definition bindings. | |
| 1208 | ;; | |
| 1209 | ;; Subforms of a begin, let-syntax, or letrec-syntax are spliced | |
| 1210 | ;; into the body. | |
| 1211 | ;; | |
| 1212 | ;; outer-form is fully wrapped w/source | |
| 1213 | (lambda (body outer-form r w) | |
| 1214 | (let* ((r (cons '("placeholder" . (placeholder)) r)) | |
| 1215 | (ribcage (make-empty-ribcage)) | |
| 1216 | (w (make-wrap (wrap-marks w) (cons ribcage (wrap-subst w))))) | |
| 1217 | (let parse ((body (map (lambda (x) (cons r (wrap x w))) body)) | |
| 1218 | (ids '()) (labels '()) (vars '()) (vals '()) (bindings '())) | |
| 1219 | (if (null? body) | |
| 1220 | (syntax-error outer-form "no expressions in body") | |
| 1221 | (let ((e (cdar body)) (er (caar body))) | |
| 1222 | (call-with-values | |
| 1223 | (lambda () (syntax-type e er empty-wrap no-source ribcage)) | |
| 1224 | (lambda (type value e w s) | |
| 1225 | (case type | |
| 1226 | ((define-form) | |
| 1227 | (let ((id (wrap value w)) (label (gen-label))) | |
| 1228 | (let ((var (gen-var id))) | |
| 1229 | (extend-ribcage! ribcage id label) | |
| 1230 | (parse (cdr body) | |
| 1231 | (cons id ids) (cons label labels) | |
| 1232 | (cons var vars) (cons (cons er (wrap e w)) vals) | |
| 1233 | (cons (make-binding 'lexical var) bindings))))) | |
| 1234 | ((define-syntax-form) | |
| 1235 | (let ((id (wrap value w)) (label (gen-label))) | |
| 1236 | (extend-ribcage! ribcage id label) | |
| 1237 | (parse (cdr body) | |
| 1238 | (cons id ids) (cons label labels) | |
| 1239 | vars vals | |
| 1240 | (cons (make-binding 'macro (cons er (wrap e w))) | |
| 1241 | bindings)))) | |
| 1242 | ((begin-form) | |
| 1243 | (syntax-case e () | |
| 1244 | ((_ e1 ...) | |
| 1245 | (parse (let f ((forms (syntax (e1 ...)))) | |
| 1246 | (if (null? forms) | |
| 1247 | (cdr body) | |
| 1248 | (cons (cons er (wrap (car forms) w)) | |
| 1249 | (f (cdr forms))))) | |
| 1250 | ids labels vars vals bindings)))) | |
| 1251 | ((local-syntax-form) | |
| 1252 | (chi-local-syntax value e er w s | |
| 1253 | (lambda (forms er w s) | |
| 1254 | (parse (let f ((forms forms)) | |
| 1255 | (if (null? forms) | |
| 1256 | (cdr body) | |
| 1257 | (cons (cons er (wrap (car forms) w)) | |
| 1258 | (f (cdr forms))))) | |
| 1259 | ids labels vars vals bindings)))) | |
| 1260 | (else ; found a non-definition | |
| 1261 | (if (null? ids) | |
| 1262 | (build-sequence no-source | |
| 1263 | (map (lambda (x) | |
| 1264 | (chi (cdr x) (car x) empty-wrap)) | |
| 1265 | (cons (cons er (source-wrap e w s)) | |
| 1266 | (cdr body)))) | |
| 1267 | (begin | |
| 1268 | (if (not (valid-bound-ids? ids)) | |
| 1269 | (syntax-error outer-form | |
| 1270 | "invalid or duplicate identifier in definition")) | |
| 1271 | (let loop ((bs bindings) (er-cache #f) (r-cache #f)) | |
| 1272 | (if (not (null? bs)) | |
| 1273 | (let* ((b (car bs))) | |
| 1274 | (if (eq? (car b) 'macro) | |
| 1275 | (let* ((er (cadr b)) | |
| 1276 | (r-cache | |
| 1277 | (if (eq? er er-cache) | |
| 1278 | r-cache | |
| 1279 | (macros-only-env er)))) | |
| 1280 | (set-cdr! b | |
| 1281 | (eval-local-transformer | |
| 1282 | (chi (cddr b) r-cache empty-wrap))) | |
| 1283 | (loop (cdr bs) er r-cache)) | |
| 1284 | (loop (cdr bs) er-cache r-cache))))) | |
| 1285 | (set-cdr! r (extend-env labels bindings (cdr r))) | |
| 1286 | (build-letrec no-source | |
| 1287 | vars | |
| 1288 | (map (lambda (x) | |
| 1289 | (chi (cdr x) (car x) empty-wrap)) | |
| 1290 | vals) | |
| 1291 | (build-sequence no-source | |
| 1292 | (map (lambda (x) | |
| 1293 | (chi (cdr x) (car x) empty-wrap)) | |
| 1294 | (cons (cons er (source-wrap e w s)) | |
| 1295 | (cdr body))))))))))))))))) | |
| 1296 | ||
| 1297 | (define chi-lambda-clause | |
| 1298 | (lambda (e c r w k) | |
| 1299 | (syntax-case c () | |
| 1300 | (((id ...) e1 e2 ...) | |
| 1301 | (let ((ids (syntax (id ...)))) | |
| 1302 | (if (not (valid-bound-ids? ids)) | |
| 1303 | (syntax-error e "invalid parameter list in") | |
| 1304 | (let ((labels (gen-labels ids)) | |
| 1305 | (new-vars (map gen-var ids))) | |
| 1306 | (k new-vars | |
| 1307 | (chi-body (syntax (e1 e2 ...)) | |
| 1308 | e | |
| 1309 | (extend-var-env labels new-vars r) | |
| 1310 | (make-binding-wrap ids labels w))))))) | |
| 1311 | ((ids e1 e2 ...) | |
| 1312 | (let ((old-ids (lambda-var-list (syntax ids)))) | |
| 1313 | (if (not (valid-bound-ids? old-ids)) | |
| 1314 | (syntax-error e "invalid parameter list in") | |
| 1315 | (let ((labels (gen-labels old-ids)) | |
| 1316 | (new-vars (map gen-var old-ids))) | |
| 1317 | (k (let f ((ls1 (cdr new-vars)) (ls2 (car new-vars))) | |
| 1318 | (if (null? ls1) | |
| 1319 | ls2 | |
| 1320 | (f (cdr ls1) (cons (car ls1) ls2)))) | |
| 1321 | (chi-body (syntax (e1 e2 ...)) | |
| 1322 | e | |
| 1323 | (extend-var-env labels new-vars r) | |
| 1324 | (make-binding-wrap old-ids labels w))))))) | |
| 1325 | (_ (syntax-error e))))) | |
| 1326 | ||
| 1327 | (define chi-local-syntax | |
| 1328 | (lambda (rec? e r w s k) | |
| 1329 | (syntax-case e () | |
| 1330 | ((_ ((id val) ...) e1 e2 ...) | |
| 1331 | (let ((ids (syntax (id ...)))) | |
| 1332 | (if (not (valid-bound-ids? ids)) | |
| 1333 | (syntax-error e "duplicate bound keyword in") | |
| 1334 | (let ((labels (gen-labels ids))) | |
| 1335 | (let ((new-w (make-binding-wrap ids labels w))) | |
| 1336 | (k (syntax (e1 e2 ...)) | |
| 1337 | (extend-env | |
| 1338 | labels | |
| 1339 | (let ((w (if rec? new-w w)) | |
| 1340 | (trans-r (macros-only-env r))) | |
| 1341 | (map (lambda (x) | |
| 1342 | (make-binding 'macro | |
| 1343 | (eval-local-transformer (chi x trans-r w)))) | |
| 1344 | (syntax (val ...)))) | |
| 1345 | r) | |
| 1346 | new-w | |
| 1347 | s)))))) | |
| 1348 | (_ (syntax-error (source-wrap e w s)))))) | |
| 1349 | ||
| 1350 | (define eval-local-transformer | |
| 1351 | (lambda (expanded) | |
| 1352 | (let ((p (local-eval-hook expanded))) | |
| 1353 | (if (procedure? p) | |
| 1354 | p | |
| 80f225df | 1355 | (syntax-error p "nonprocedure transformer"))))) |
| a63812a2 JB |
1356 | |
| 1357 | (define chi-void | |
| 1358 | (lambda () | |
| 1359 | (build-application no-source (build-primref no-source 'void) '()))) | |
| 1360 | ||
| 1361 | (define ellipsis? | |
| 1362 | (lambda (x) | |
| 1363 | (and (nonsymbol-id? x) | |
| 1364 | (free-id=? x (syntax (... ...)))))) | |
| 1365 | ||
| 1366 | ;;; data | |
| 1367 | ||
| 1368 | ;;; strips all annotations from potentially circular reader output | |
| 1369 | ||
| 1370 | (define strip-annotation | |
| 1371 | (lambda (x parent) | |
| 1372 | (cond | |
| 1373 | ((pair? x) | |
| 1374 | (let ((new (cons #f #f))) | |
| 979933ab | 1375 | (if parent (set-annotation-stripped! parent new)) |
| a63812a2 JB |
1376 | (set-car! new (strip-annotation (car x) #f)) |
| 1377 | (set-cdr! new (strip-annotation (cdr x) #f)) | |
| 1378 | new)) | |
| 1379 | ((annotation? x) | |
| 1380 | (or (annotation-stripped x) | |
| 1381 | (strip-annotation (annotation-expression x) x))) | |
| 1382 | ((vector? x) | |
| 1383 | (let ((new (make-vector (vector-length x)))) | |
| 979933ab | 1384 | (if parent (set-annotation-stripped! parent new)) |
| a63812a2 JB |
1385 | (let loop ((i (- (vector-length x) 1))) |
| 1386 | (unless (fx< i 0) | |
| 1387 | (vector-set! new i (strip-annotation (vector-ref x i) #f)) | |
| 1388 | (loop (fx- i 1)))) | |
| 1389 | new)) | |
| 1390 | (else x)))) | |
| 1391 | ||
| 1392 | ;;; strips syntax-objects down to top-wrap; if top-wrap is layered directly | |
| 1393 | ;;; on an annotation, strips the annotation as well. | |
| 1394 | ;;; since only the head of a list is annotated by the reader, not each pair | |
| 1395 | ;;; in the spine, we also check for pairs whose cars are annotated in case | |
| 1396 | ;;; we've been passed the cdr of an annotated list | |
| 1397 | ||
| 1398 | (define strip | |
| 1399 | (lambda (x w) | |
| 1400 | (if (top-marked? w) | |
| 1401 | (if (or (annotation? x) (and (pair? x) (annotation? (car x)))) | |
| 1402 | (strip-annotation x #f) | |
| 1403 | x) | |
| 1404 | (let f ((x x)) | |
| 1405 | (cond | |
| 1406 | ((syntax-object? x) | |
| 1407 | (strip (syntax-object-expression x) (syntax-object-wrap x))) | |
| 1408 | ((pair? x) | |
| 1409 | (let ((a (f (car x))) (d (f (cdr x)))) | |
| 1410 | (if (and (eq? a (car x)) (eq? d (cdr x))) | |
| 1411 | x | |
| 1412 | (cons a d)))) | |
| 1413 | ((vector? x) | |
| 1414 | (let ((old (vector->list x))) | |
| 1415 | (let ((new (map f old))) | |
| 1416 | (if (andmap eq? old new) x (list->vector new))))) | |
| 1417 | (else x)))))) | |
| 1418 | ||
| 1419 | ;;; lexical variables | |
| 1420 | ||
| 1421 | (define gen-var | |
| 1422 | (lambda (id) | |
| 1423 | (let ((id (if (syntax-object? id) (syntax-object-expression id) id))) | |
| 1424 | (if (annotation? id) | |
| 1425 | (build-lexical-var (annotation-source id) (annotation-expression id)) | |
| 1426 | (build-lexical-var no-source id))))) | |
| 1427 | ||
| 1428 | (define lambda-var-list | |
| 1429 | (lambda (vars) | |
| 1430 | (let lvl ((vars vars) (ls '()) (w empty-wrap)) | |
| 1431 | (cond | |
| 1432 | ((pair? vars) (lvl (cdr vars) (cons (wrap (car vars) w) ls) w)) | |
| 1433 | ((id? vars) (cons (wrap vars w) ls)) | |
| 1434 | ((null? vars) ls) | |
| 1435 | ((syntax-object? vars) | |
| 1436 | (lvl (syntax-object-expression vars) | |
| 1437 | ls | |
| 1438 | (join-wraps w (syntax-object-wrap vars)))) | |
| 1439 | ((annotation? vars) | |
| 1440 | (lvl (annotation-expression vars) ls w)) | |
| 1441 | ; include anything else to be caught by subsequent error | |
| 1442 | ; checking | |
| 1443 | (else (cons vars ls)))))) | |
| 1444 | ||
| 1445 | ;;; core transformers | |
| 1446 | ||
| 1447 | (global-extend 'local-syntax 'letrec-syntax #t) | |
| 1448 | (global-extend 'local-syntax 'let-syntax #f) | |
| 1449 | ||
| 1450 | (global-extend 'core 'fluid-let-syntax | |
| 1451 | (lambda (e r w s) | |
| 1452 | (syntax-case e () | |
| 1453 | ((_ ((var val) ...) e1 e2 ...) | |
| 1454 | (valid-bound-ids? (syntax (var ...))) | |
| 1455 | (let ((names (map (lambda (x) (id-var-name x w)) (syntax (var ...))))) | |
| 1456 | (for-each | |
| 1457 | (lambda (id n) | |
| 1458 | (case (binding-type (lookup n r)) | |
| 1459 | ((displaced-lexical) | |
| 1460 | (syntax-error (source-wrap id w s) | |
| 1461 | "identifier out of context")))) | |
| 1462 | (syntax (var ...)) | |
| 1463 | names) | |
| 1464 | (chi-body | |
| 1465 | (syntax (e1 e2 ...)) | |
| 1466 | (source-wrap e w s) | |
| 1467 | (extend-env | |
| 1468 | names | |
| 1469 | (let ((trans-r (macros-only-env r))) | |
| 1470 | (map (lambda (x) | |
| 1471 | (make-binding 'macro | |
| 1472 | (eval-local-transformer (chi x trans-r w)))) | |
| 1473 | (syntax (val ...)))) | |
| 1474 | r) | |
| 1475 | w))) | |
| 1476 | (_ (syntax-error (source-wrap e w s)))))) | |
| 1477 | ||
| 1478 | (global-extend 'core 'quote | |
| 1479 | (lambda (e r w s) | |
| 1480 | (syntax-case e () | |
| 1481 | ((_ e) (build-data s (strip (syntax e) w))) | |
| 1482 | (_ (syntax-error (source-wrap e w s)))))) | |
| 1483 | ||
| 1484 | (global-extend 'core 'syntax | |
| 1485 | (let () | |
| 1486 | (define gen-syntax | |
| 1487 | (lambda (src e r maps ellipsis?) | |
| 1488 | (if (id? e) | |
| 1489 | (let ((label (id-var-name e empty-wrap))) | |
| 1490 | (let ((b (lookup label r))) | |
| 1491 | (if (eq? (binding-type b) 'syntax) | |
| 1492 | (call-with-values | |
| 1493 | (lambda () | |
| 1494 | (let ((var.lev (binding-value b))) | |
| 1495 | (gen-ref src (car var.lev) (cdr var.lev) maps))) | |
| 1496 | (lambda (var maps) (values `(ref ,var) maps))) | |
| 1497 | (if (ellipsis? e) | |
| 1498 | (syntax-error src "misplaced ellipsis in syntax form") | |
| 1499 | (values `(quote ,e) maps))))) | |
| 1500 | (syntax-case e () | |
| 1501 | ((dots e) | |
| 1502 | (ellipsis? (syntax dots)) | |
| 1503 | (gen-syntax src (syntax e) r maps (lambda (x) #f))) | |
| 1504 | ((x dots . y) | |
| 1505 | ; this could be about a dozen lines of code, except that we | |
| 1506 | ; choose to handle (syntax (x ... ...)) forms | |
| 1507 | (ellipsis? (syntax dots)) | |
| 1508 | (let f ((y (syntax y)) | |
| 1509 | (k (lambda (maps) | |
| 1510 | (call-with-values | |
| 1511 | (lambda () | |
| 1512 | (gen-syntax src (syntax x) r | |
| 1513 | (cons '() maps) ellipsis?)) | |
| 1514 | (lambda (x maps) | |
| 1515 | (if (null? (car maps)) | |
| 1516 | (syntax-error src | |
| 1517 | "extra ellipsis in syntax form") | |
| 1518 | (values (gen-map x (car maps)) | |
| 1519 | (cdr maps)))))))) | |
| 1520 | (syntax-case y () | |
| 1521 | ((dots . y) | |
| 1522 | (ellipsis? (syntax dots)) | |
| 1523 | (f (syntax y) | |
| 1524 | (lambda (maps) | |
| 1525 | (call-with-values | |
| 1526 | (lambda () (k (cons '() maps))) | |
| 1527 | (lambda (x maps) | |
| 1528 | (if (null? (car maps)) | |
| 1529 | (syntax-error src | |
| 1530 | "extra ellipsis in syntax form") | |
| 1531 | (values (gen-mappend x (car maps)) | |
| 1532 | (cdr maps)))))))) | |
| 1533 | (_ (call-with-values | |
| 1534 | (lambda () (gen-syntax src y r maps ellipsis?)) | |
| 1535 | (lambda (y maps) | |
| 1536 | (call-with-values | |
| 1537 | (lambda () (k maps)) | |
| 1538 | (lambda (x maps) | |
| 1539 | (values (gen-append x y) maps))))))))) | |
| 1540 | ((x . y) | |
| 1541 | (call-with-values | |
| 1542 | (lambda () (gen-syntax src (syntax x) r maps ellipsis?)) | |
| 1543 | (lambda (x maps) | |
| 1544 | (call-with-values | |
| 1545 | (lambda () (gen-syntax src (syntax y) r maps ellipsis?)) | |
| 1546 | (lambda (y maps) (values (gen-cons x y) maps)))))) | |
| 1547 | (#(e1 e2 ...) | |
| 1548 | (call-with-values | |
| 1549 | (lambda () | |
| 1550 | (gen-syntax src (syntax (e1 e2 ...)) r maps ellipsis?)) | |
| 1551 | (lambda (e maps) (values (gen-vector e) maps)))) | |
| 1552 | (_ (values `(quote ,e) maps)))))) | |
| 1553 | ||
| 1554 | (define gen-ref | |
| 1555 | (lambda (src var level maps) | |
| 1556 | (if (fx= level 0) | |
| 1557 | (values var maps) | |
| 1558 | (if (null? maps) | |
| 1559 | (syntax-error src "missing ellipsis in syntax form") | |
| 1560 | (call-with-values | |
| 1561 | (lambda () (gen-ref src var (fx- level 1) (cdr maps))) | |
| 1562 | (lambda (outer-var outer-maps) | |
| 1563 | (let ((b (assq outer-var (car maps)))) | |
| 1564 | (if b | |
| 1565 | (values (cdr b) maps) | |
| 1566 | (let ((inner-var (gen-var 'tmp))) | |
| 1567 | (values inner-var | |
| 1568 | (cons (cons (cons outer-var inner-var) | |
| 1569 | (car maps)) | |
| 1570 | outer-maps))))))))))) | |
| 1571 | ||
| 1572 | (define gen-mappend | |
| 1573 | (lambda (e map-env) | |
| 1574 | `(apply (primitive append) ,(gen-map e map-env)))) | |
| 1575 | ||
| 1576 | (define gen-map | |
| 1577 | (lambda (e map-env) | |
| 1578 | (let ((formals (map cdr map-env)) | |
| 1579 | (actuals (map (lambda (x) `(ref ,(car x))) map-env))) | |
| 1580 | (cond | |
| 1581 | ((eq? (car e) 'ref) | |
| 1582 | ; identity map equivalence: | |
| 1583 | ; (map (lambda (x) x) y) == y | |
| 1584 | (car actuals)) | |
| 1585 | ((andmap | |
| 1586 | (lambda (x) (and (eq? (car x) 'ref) (memq (cadr x) formals))) | |
| 1587 | (cdr e)) | |
| 1588 | ; eta map equivalence: | |
| 1589 | ; (map (lambda (x ...) (f x ...)) y ...) == (map f y ...) | |
| 1590 | `(map (primitive ,(car e)) | |
| 1591 | ,@(map (let ((r (map cons formals actuals))) | |
| 1592 | (lambda (x) (cdr (assq (cadr x) r)))) | |
| 1593 | (cdr e)))) | |
| 1594 | (else `(map (lambda ,formals ,e) ,@actuals)))))) | |
| 1595 | ||
| 1596 | (define gen-cons | |
| 1597 | (lambda (x y) | |
| 1598 | (case (car y) | |
| 1599 | ((quote) | |
| 1600 | (if (eq? (car x) 'quote) | |
| 1601 | `(quote (,(cadr x) . ,(cadr y))) | |
| 1602 | (if (eq? (cadr y) '()) | |
| 1603 | `(list ,x) | |
| 1604 | `(cons ,x ,y)))) | |
| 1605 | ((list) `(list ,x ,@(cdr y))) | |
| 1606 | (else `(cons ,x ,y))))) | |
| 1607 | ||
| 1608 | (define gen-append | |
| 1609 | (lambda (x y) | |
| 1610 | (if (equal? y '(quote ())) | |
| 1611 | x | |
| 1612 | `(append ,x ,y)))) | |
| 1613 | ||
| 1614 | (define gen-vector | |
| 1615 | (lambda (x) | |
| 1616 | (cond | |
| 1617 | ((eq? (car x) 'list) `(vector ,@(cdr x))) | |
| 1618 | ((eq? (car x) 'quote) `(quote #(,@(cadr x)))) | |
| 1619 | (else `(list->vector ,x))))) | |
| 1620 | ||
| 1621 | ||
| 1622 | (define regen | |
| 1623 | (lambda (x) | |
| 1624 | (case (car x) | |
| 1625 | ((ref) (build-lexical-reference 'value no-source (cadr x))) | |
| 1626 | ((primitive) (build-primref no-source (cadr x))) | |
| 1627 | ((quote) (build-data no-source (cadr x))) | |
| 1628 | ((lambda) (build-lambda no-source (cadr x) (regen (caddr x)))) | |
| 1629 | ((map) (let ((ls (map regen (cdr x)))) | |
| 1630 | (build-application no-source | |
| 1631 | (if (fx= (length ls) 2) | |
| 1632 | (build-primref no-source 'map) | |
| 1633 | ; really need to do our own checking here | |
| 1634 | (build-primref no-source 2 'map)) ; require error check | |
| 1635 | ls))) | |
| 1636 | (else (build-application no-source | |
| 1637 | (build-primref no-source (car x)) | |
| 1638 | (map regen (cdr x))))))) | |
| 1639 | ||
| 1640 | (lambda (e r w s) | |
| 1641 | (let ((e (source-wrap e w s))) | |
| 1642 | (syntax-case e () | |
| 1643 | ((_ x) | |
| 1644 | (call-with-values | |
| 1645 | (lambda () (gen-syntax e (syntax x) r '() ellipsis?)) | |
| 1646 | (lambda (e maps) (regen e)))) | |
| 1647 | (_ (syntax-error e))))))) | |
| 1648 | ||
| 1649 | ||
| 1650 | (global-extend 'core 'lambda | |
| 1651 | (lambda (e r w s) | |
| 1652 | (syntax-case e () | |
| 1653 | ((_ . c) | |
| 1654 | (chi-lambda-clause (source-wrap e w s) (syntax c) r w | |
| 1655 | (lambda (vars body) (build-lambda s vars body))))))) | |
| 1656 | ||
| 1657 | ||
| 1658 | (global-extend 'core 'let | |
| 1659 | (let () | |
| 1660 | (define (chi-let e r w s constructor ids vals exps) | |
| 1661 | (if (not (valid-bound-ids? ids)) | |
| 1662 | (syntax-error e "duplicate bound variable in") | |
| 1663 | (let ((labels (gen-labels ids)) | |
| 1664 | (new-vars (map gen-var ids))) | |
| 1665 | (let ((nw (make-binding-wrap ids labels w)) | |
| 1666 | (nr (extend-var-env labels new-vars r))) | |
| 1667 | (constructor s | |
| 1668 | new-vars | |
| 1669 | (map (lambda (x) (chi x r w)) vals) | |
| 1670 | (chi-body exps (source-wrap e nw s) nr nw)))))) | |
| 1671 | (lambda (e r w s) | |
| 1672 | (syntax-case e () | |
| 1673 | ((_ ((id val) ...) e1 e2 ...) | |
| 1674 | (chi-let e r w s | |
| 1675 | build-let | |
| 1676 | (syntax (id ...)) | |
| 1677 | (syntax (val ...)) | |
| 1678 | (syntax (e1 e2 ...)))) | |
| 1679 | ((_ f ((id val) ...) e1 e2 ...) | |
| 1680 | (id? (syntax f)) | |
| 1681 | (chi-let e r w s | |
| 1682 | build-named-let | |
| 1683 | (syntax (f id ...)) | |
| 1684 | (syntax (val ...)) | |
| 1685 | (syntax (e1 e2 ...)))) | |
| 1686 | (_ (syntax-error (source-wrap e w s))))))) | |
| 1687 | ||
| 1688 | ||
| 1689 | (global-extend 'core 'letrec | |
| 1690 | (lambda (e r w s) | |
| 1691 | (syntax-case e () | |
| 1692 | ((_ ((id val) ...) e1 e2 ...) | |
| 1693 | (let ((ids (syntax (id ...)))) | |
| 1694 | (if (not (valid-bound-ids? ids)) | |
| 1695 | (syntax-error e "duplicate bound variable in") | |
| 1696 | (let ((labels (gen-labels ids)) | |
| 1697 | (new-vars (map gen-var ids))) | |
| 1698 | (let ((w (make-binding-wrap ids labels w)) | |
| 1699 | (r (extend-var-env labels new-vars r))) | |
| 1700 | (build-letrec s | |
| 1701 | new-vars | |
| 1702 | (map (lambda (x) (chi x r w)) (syntax (val ...))) | |
| 1703 | (chi-body (syntax (e1 e2 ...)) (source-wrap e w s) r w))))))) | |
| 1704 | (_ (syntax-error (source-wrap e w s)))))) | |
| 1705 | ||
| 1706 | ||
| 1707 | (global-extend 'core 'set! | |
| 1708 | (lambda (e r w s) | |
| 1709 | (syntax-case e () | |
| 1710 | ((_ id val) | |
| 1711 | (id? (syntax id)) | |
| 1712 | (let ((val (chi (syntax val) r w)) | |
| 1713 | (n (id-var-name (syntax id) w))) | |
| 1714 | (let ((b (lookup n r))) | |
| 1715 | (case (binding-type b) | |
| 1716 | ((lexical) | |
| 1717 | (build-lexical-assignment s (binding-value b) val)) | |
| 1718 | ((global) (build-global-assignment s n val)) | |
| 1719 | ((displaced-lexical) | |
| 1720 | (syntax-error (wrap (syntax id) w) | |
| 1721 | "identifier out of context")) | |
| 1722 | (else (syntax-error (source-wrap e w s))))))) | |
| fde75b7c MD |
1723 | ((_ (getter arg ...) val) |
| 1724 | (build-application s | |
| 1725 | (chi (syntax (setter getter)) r w) | |
| 1726 | (map (lambda (e) (chi e r w)) | |
| 1727 | (syntax (arg ... val))))) | |
| a63812a2 JB |
1728 | (_ (syntax-error (source-wrap e w s)))))) |
| 1729 | ||
| 1730 | (global-extend 'begin 'begin '()) | |
| 1731 | ||
| 1732 | (global-extend 'define 'define '()) | |
| 1733 | ||
| 1734 | (global-extend 'define-syntax 'define-syntax '()) | |
| 1735 | ||
| 1736 | (global-extend 'eval-when 'eval-when '()) | |
| 1737 | ||
| 1738 | (global-extend 'core 'syntax-case | |
| 1739 | (let () | |
| 1740 | (define convert-pattern | |
| 1741 | ; accepts pattern & keys | |
| 1742 | ; returns syntax-dispatch pattern & ids | |
| 1743 | (lambda (pattern keys) | |
| 1744 | (let cvt ((p pattern) (n 0) (ids '())) | |
| 1745 | (if (id? p) | |
| 1746 | (if (bound-id-member? p keys) | |
| 1747 | (values (vector 'free-id p) ids) | |
| 1748 | (values 'any (cons (cons p n) ids))) | |
| 1749 | (syntax-case p () | |
| 1750 | ((x dots) | |
| 1751 | (ellipsis? (syntax dots)) | |
| 1752 | (call-with-values | |
| 1753 | (lambda () (cvt (syntax x) (fx+ n 1) ids)) | |
| 1754 | (lambda (p ids) | |
| 1755 | (values (if (eq? p 'any) 'each-any (vector 'each p)) | |
| 1756 | ids)))) | |
| 1757 | ((x . y) | |
| 1758 | (call-with-values | |
| 1759 | (lambda () (cvt (syntax y) n ids)) | |
| 1760 | (lambda (y ids) | |
| 1761 | (call-with-values | |
| 1762 | (lambda () (cvt (syntax x) n ids)) | |
| 1763 | (lambda (x ids) | |
| 1764 | (values (cons x y) ids)))))) | |
| 1765 | (() (values '() ids)) | |
| 1766 | (#(x ...) | |
| 1767 | (call-with-values | |
| 1768 | (lambda () (cvt (syntax (x ...)) n ids)) | |
| 1769 | (lambda (p ids) (values (vector 'vector p) ids)))) | |
| 1770 | (x (values (vector 'atom (strip p empty-wrap)) ids))))))) | |
| 1771 | ||
| 1772 | (define build-dispatch-call | |
| 1773 | (lambda (pvars exp y r) | |
| 1774 | (let ((ids (map car pvars)) (levels (map cdr pvars))) | |
| 1775 | (let ((labels (gen-labels ids)) (new-vars (map gen-var ids))) | |
| 1776 | (build-application no-source | |
| 1777 | (build-primref no-source 'apply) | |
| 1778 | (list (build-lambda no-source new-vars | |
| 1779 | (chi exp | |
| 1780 | (extend-env | |
| 1781 | labels | |
| 1782 | (map (lambda (var level) | |
| 1783 | (make-binding 'syntax `(,var . ,level))) | |
| 1784 | new-vars | |
| 1785 | (map cdr pvars)) | |
| 1786 | r) | |
| 1787 | (make-binding-wrap ids labels empty-wrap))) | |
| 1788 | y)))))) | |
| 1789 | ||
| 1790 | (define gen-clause | |
| 1791 | (lambda (x keys clauses r pat fender exp) | |
| 1792 | (call-with-values | |
| 1793 | (lambda () (convert-pattern pat keys)) | |
| 1794 | (lambda (p pvars) | |
| 1795 | (cond | |
| 1796 | ((not (distinct-bound-ids? (map car pvars))) | |
| 1797 | (syntax-error pat | |
| 1798 | "duplicate pattern variable in syntax-case pattern")) | |
| 1799 | ((not (andmap (lambda (x) (not (ellipsis? (car x)))) pvars)) | |
| 1800 | (syntax-error pat | |
| 1801 | "misplaced ellipsis in syntax-case pattern")) | |
| 1802 | (else | |
| 1803 | (let ((y (gen-var 'tmp))) | |
| 1804 | ; fat finger binding and references to temp variable y | |
| 1805 | (build-application no-source | |
| 1806 | (build-lambda no-source (list y) | |
| 1807 | (let ((y (build-lexical-reference 'value no-source y))) | |
| 1808 | (build-conditional no-source | |
| 1809 | (syntax-case fender () | |
| 1810 | (#t y) | |
| 1811 | (_ (build-conditional no-source | |
| 1812 | y | |
| 1813 | (build-dispatch-call pvars fender y r) | |
| 1814 | (build-data no-source #f)))) | |
| 1815 | (build-dispatch-call pvars exp y r) | |
| 1816 | (gen-syntax-case x keys clauses r)))) | |
| 1817 | (list (if (eq? p 'any) | |
| 1818 | (build-application no-source | |
| 1819 | (build-primref no-source 'list) | |
| 1820 | (list x)) | |
| 1821 | (build-application no-source | |
| 1822 | (build-primref no-source 'syntax-dispatch) | |
| 1823 | (list x (build-data no-source p))))))))))))) | |
| 1824 | ||
| 1825 | (define gen-syntax-case | |
| 1826 | (lambda (x keys clauses r) | |
| 1827 | (if (null? clauses) | |
| 1828 | (build-application no-source | |
| 1829 | (build-primref no-source 'syntax-error) | |
| 1830 | (list x)) | |
| 1831 | (syntax-case (car clauses) () | |
| 1832 | ((pat exp) | |
| 1833 | (if (and (id? (syntax pat)) | |
| 1834 | (andmap (lambda (x) (not (free-id=? (syntax pat) x))) | |
| 1835 | (cons (syntax (... ...)) keys))) | |
| 1836 | (let ((labels (list (gen-label))) | |
| 1837 | (var (gen-var (syntax pat)))) | |
| 1838 | (build-application no-source | |
| 1839 | (build-lambda no-source (list var) | |
| 1840 | (chi (syntax exp) | |
| 1841 | (extend-env labels | |
| 1842 | (list (make-binding 'syntax `(,var . 0))) | |
| 1843 | r) | |
| 1844 | (make-binding-wrap (syntax (pat)) | |
| 1845 | labels empty-wrap))) | |
| 1846 | (list x))) | |
| 1847 | (gen-clause x keys (cdr clauses) r | |
| 1848 | (syntax pat) #t (syntax exp)))) | |
| 1849 | ((pat fender exp) | |
| 1850 | (gen-clause x keys (cdr clauses) r | |
| 1851 | (syntax pat) (syntax fender) (syntax exp))) | |
| 1852 | (_ (syntax-error (car clauses) "invalid syntax-case clause")))))) | |
| 1853 | ||
| 1854 | (lambda (e r w s) | |
| 1855 | (let ((e (source-wrap e w s))) | |
| 1856 | (syntax-case e () | |
| 1857 | ((_ val (key ...) m ...) | |
| 1858 | (if (andmap (lambda (x) (and (id? x) (not (ellipsis? x)))) | |
| 1859 | (syntax (key ...))) | |
| 1860 | (let ((x (gen-var 'tmp))) | |
| 1861 | ; fat finger binding and references to temp variable x | |
| 1862 | (build-application s | |
| 1863 | (build-lambda no-source (list x) | |
| 1864 | (gen-syntax-case (build-lexical-reference 'value no-source x) | |
| 1865 | (syntax (key ...)) (syntax (m ...)) | |
| 1866 | r)) | |
| 1867 | (list (chi (syntax val) r empty-wrap)))) | |
| 1868 | (syntax-error e "invalid literals list in")))))))) | |
| 1869 | ||
| 1870 | ;;; The portable sc-expand seeds chi-top's mode m with 'e (for | |
| 1871 | ;;; evaluating) and esew (which stands for "eval syntax expanders | |
| 1872 | ;;; when") with '(eval). In Chez Scheme, m is set to 'c instead of e | |
| 1873 | ;;; if we are compiling a file, and esew is set to | |
| 1874 | ;;; (eval-syntactic-expanders-when), which defaults to the list | |
| 1875 | ;;; '(compile load eval). This means that, by default, top-level | |
| 1876 | ;;; syntactic definitions are evaluated immediately after they are | |
| 1877 | ;;; expanded, and the expanded definitions are also residualized into | |
| 1878 | ;;; the object file if we are compiling a file. | |
| 1879 | (set! sc-expand | |
| 1880 | (let ((m 'e) (esew '(eval))) | |
| 1881 | (lambda (x) | |
| 1882 | (if (and (pair? x) (equal? (car x) noexpand)) | |
| 1883 | (cadr x) | |
| 1884 | (chi-top x null-env top-wrap m esew))))) | |
| 1885 | ||
| 1886 | (set! sc-expand3 | |
| 1887 | (let ((m 'e) (esew '(eval))) | |
| 1888 | (lambda (x . rest) | |
| 1889 | (if (and (pair? x) (equal? (car x) noexpand)) | |
| 1890 | (cadr x) | |
| 1891 | (chi-top x | |
| 1892 | null-env | |
| 1893 | top-wrap | |
| 1894 | (if (null? rest) m (car rest)) | |
| 1895 | (if (or (null? rest) (null? (cdr rest))) | |
| 1896 | esew | |
| 1897 | (cadr rest))))))) | |
| 1898 | ||
| 1899 | (set! identifier? | |
| 1900 | (lambda (x) | |
| 1901 | (nonsymbol-id? x))) | |
| 1902 | ||
| 1903 | (set! datum->syntax-object | |
| 1904 | (lambda (id datum) | |
| a63812a2 JB |
1905 | (make-syntax-object datum (syntax-object-wrap id)))) |
| 1906 | ||
| 1907 | (set! syntax-object->datum | |
| 1908 | ; accepts any object, since syntax objects may consist partially | |
| 1909 | ; or entirely of unwrapped, nonsymbolic data | |
| 1910 | (lambda (x) | |
| 1911 | (strip x empty-wrap))) | |
| 1912 | ||
| 1913 | (set! generate-temporaries | |
| 1914 | (lambda (ls) | |
| 1915 | (arg-check list? ls 'generate-temporaries) | |
| 1916 | (map (lambda (x) (wrap (gensym-hook) top-wrap)) ls))) | |
| 1917 | ||
| 1918 | (set! free-identifier=? | |
| 1919 | (lambda (x y) | |
| 1920 | (arg-check nonsymbol-id? x 'free-identifier=?) | |
| 1921 | (arg-check nonsymbol-id? y 'free-identifier=?) | |
| 1922 | (free-id=? x y))) | |
| 1923 | ||
| 1924 | (set! bound-identifier=? | |
| 1925 | (lambda (x y) | |
| 1926 | (arg-check nonsymbol-id? x 'bound-identifier=?) | |
| 1927 | (arg-check nonsymbol-id? y 'bound-identifier=?) | |
| 1928 | (bound-id=? x y))) | |
| 1929 | ||
| 1930 | (set! syntax-error | |
| 1931 | (lambda (object . messages) | |
| 1932 | (for-each (lambda (x) (arg-check string? x 'syntax-error)) messages) | |
| 1933 | (let ((message (if (null? messages) | |
| 1934 | "invalid syntax" | |
| 1935 | (apply string-append messages)))) | |
| 1936 | (error-hook #f message (strip object empty-wrap))))) | |
| 1937 | ||
| 1938 | (set! install-global-transformer | |
| 1939 | (lambda (sym v) | |
| 1940 | (arg-check symbol? sym 'define-syntax) | |
| 1941 | (arg-check procedure? v 'define-syntax) | |
| 1942 | (global-extend 'macro sym v))) | |
| 1943 | ||
| 1944 | ;;; syntax-dispatch expects an expression and a pattern. If the expression | |
| 1945 | ;;; matches the pattern a list of the matching expressions for each | |
| 1946 | ;;; "any" is returned. Otherwise, #f is returned. (This use of #f will | |
| 1947 | ;;; not work on r4rs implementations that violate the ieee requirement | |
| 1948 | ;;; that #f and () be distinct.) | |
| 1949 | ||
| 1950 | ;;; The expression is matched with the pattern as follows: | |
| 1951 | ||
| 1952 | ;;; pattern: matches: | |
| 1953 | ;;; () empty list | |
| 1954 | ;;; any anything | |
| 1955 | ;;; (<pattern>1 . <pattern>2) (<pattern>1 . <pattern>2) | |
| 1956 | ;;; each-any (any*) | |
| 1957 | ;;; #(free-id <key>) <key> with free-identifier=? | |
| 1958 | ;;; #(each <pattern>) (<pattern>*) | |
| 1959 | ;;; #(vector <pattern>) (list->vector <pattern>) | |
| 1960 | ;;; #(atom <object>) <object> with "equal?" | |
| 1961 | ||
| 1962 | ;;; Vector cops out to pair under assumption that vectors are rare. If | |
| 1963 | ;;; not, should convert to: | |
| 1964 | ;;; #(vector <pattern>*) #(<pattern>*) | |
| 1965 | ||
| 1966 | (let () | |
| 1967 | ||
| 1968 | (define match-each | |
| 1969 | (lambda (e p w) | |
| 1970 | (cond | |
| 1971 | ((annotation? e) | |
| 1972 | (match-each (annotation-expression e) p w)) | |
| 1973 | ((pair? e) | |
| 1974 | (let ((first (match (car e) p w '()))) | |
| 1975 | (and first | |
| 1976 | (let ((rest (match-each (cdr e) p w))) | |
| 1977 | (and rest (cons first rest)))))) | |
| 1978 | ((null? e) '()) | |
| 1979 | ((syntax-object? e) | |
| 1980 | (match-each (syntax-object-expression e) | |
| 1981 | p | |
| 1982 | (join-wraps w (syntax-object-wrap e)))) | |
| 1983 | (else #f)))) | |
| 1984 | ||
| 1985 | (define match-each-any | |
| 1986 | (lambda (e w) | |
| 1987 | (cond | |
| 1988 | ((annotation? e) | |
| 1989 | (match-each-any (annotation-expression e) w)) | |
| 1990 | ((pair? e) | |
| 1991 | (let ((l (match-each-any (cdr e) w))) | |
| 1992 | (and l (cons (wrap (car e) w) l)))) | |
| 1993 | ((null? e) '()) | |
| 1994 | ((syntax-object? e) | |
| 1995 | (match-each-any (syntax-object-expression e) | |
| 1996 | (join-wraps w (syntax-object-wrap e)))) | |
| 1997 | (else #f)))) | |
| 1998 | ||
| 1999 | (define match-empty | |
| 2000 | (lambda (p r) | |
| 2001 | (cond | |
| 2002 | ((null? p) r) | |
| 2003 | ((eq? p 'any) (cons '() r)) | |
| 2004 | ((pair? p) (match-empty (car p) (match-empty (cdr p) r))) | |
| 2005 | ((eq? p 'each-any) (cons '() r)) | |
| 2006 | (else | |
| 2007 | (case (vector-ref p 0) | |
| 2008 | ((each) (match-empty (vector-ref p 1) r)) | |
| 2009 | ((free-id atom) r) | |
| 2010 | ((vector) (match-empty (vector-ref p 1) r))))))) | |
| 2011 | ||
| 2012 | (define match* | |
| 2013 | (lambda (e p w r) | |
| 2014 | (cond | |
| 2015 | ((null? p) (and (null? e) r)) | |
| 2016 | ((pair? p) | |
| 2017 | (and (pair? e) (match (car e) (car p) w | |
| 2018 | (match (cdr e) (cdr p) w r)))) | |
| 2019 | ((eq? p 'each-any) | |
| 2020 | (let ((l (match-each-any e w))) (and l (cons l r)))) | |
| 2021 | (else | |
| 2022 | (case (vector-ref p 0) | |
| 2023 | ((each) | |
| 2024 | (if (null? e) | |
| 2025 | (match-empty (vector-ref p 1) r) | |
| 2026 | (let ((l (match-each e (vector-ref p 1) w))) | |
| 2027 | (and l | |
| 2028 | (let collect ((l l)) | |
| 2029 | (if (null? (car l)) | |
| 2030 | r | |
| 2031 | (cons (map car l) (collect (map cdr l))))))))) | |
| 2032 | ((free-id) (and (id? e) (free-id=? (wrap e w) (vector-ref p 1)) r)) | |
| 2033 | ((atom) (and (equal? (vector-ref p 1) (strip e w)) r)) | |
| 2034 | ((vector) | |
| 2035 | (and (vector? e) | |
| 2036 | (match (vector->list e) (vector-ref p 1) w r)))))))) | |
| 2037 | ||
| 2038 | (define match | |
| 2039 | (lambda (e p w r) | |
| 2040 | (cond | |
| 2041 | ((not r) #f) | |
| 2042 | ((eq? p 'any) (cons (wrap e w) r)) | |
| 2043 | ((syntax-object? e) | |
| 2044 | (match* | |
| 2045 | (unannotate (syntax-object-expression e)) | |
| 2046 | p | |
| 2047 | (join-wraps w (syntax-object-wrap e)) | |
| 2048 | r)) | |
| 2049 | (else (match* (unannotate e) p w r))))) | |
| 2050 | ||
| 2051 | (set! syntax-dispatch | |
| 2052 | (lambda (e p) | |
| 2053 | (cond | |
| 2054 | ((eq? p 'any) (list e)) | |
| 2055 | ((syntax-object? e) | |
| 2056 | (match* (unannotate (syntax-object-expression e)) | |
| 2057 | p (syntax-object-wrap e) '())) | |
| 2058 | (else (match* (unannotate e) p empty-wrap '()))))) | |
| 80f225df MD |
2059 | |
| 2060 | (set! sc-chi chi) | |
| a63812a2 JB |
2061 | )) |
| 2062 | ) | |
| 2063 | ||
| 2064 | (define-syntax with-syntax | |
| 2065 | (lambda (x) | |
| 2066 | (syntax-case x () | |
| 2067 | ((_ () e1 e2 ...) | |
| 2068 | (syntax (begin e1 e2 ...))) | |
| 2069 | ((_ ((out in)) e1 e2 ...) | |
| 2070 | (syntax (syntax-case in () (out (begin e1 e2 ...))))) | |
| 2071 | ((_ ((out in) ...) e1 e2 ...) | |
| 2072 | (syntax (syntax-case (list in ...) () | |
| 2073 | ((out ...) (begin e1 e2 ...)))))))) | |
| 2074 | ||
| 2075 | (define-syntax syntax-rules | |
| 2076 | (lambda (x) | |
| 2077 | (syntax-case x () | |
| 2078 | ((_ (k ...) ((keyword . pattern) template) ...) | |
| 2079 | (syntax (lambda (x) | |
| 2080 | (syntax-case x (k ...) | |
| 2081 | ((dummy . pattern) (syntax template)) | |
| 2082 | ...))))))) | |
| 2083 | ||
| 2084 | (define-syntax let* | |
| 2085 | (lambda (x) | |
| 2086 | (syntax-case x () | |
| 2087 | ((let* ((x v) ...) e1 e2 ...) | |
| 2088 | (andmap identifier? (syntax (x ...))) | |
| 2089 | (let f ((bindings (syntax ((x v) ...)))) | |
| 2090 | (if (null? bindings) | |
| 2091 | (syntax (let () e1 e2 ...)) | |
| 2092 | (with-syntax ((body (f (cdr bindings))) | |
| 2093 | (binding (car bindings))) | |
| 2094 | (syntax (let (binding) body))))))))) | |
| 2095 | ||
| 2096 | (define-syntax do | |
| 2097 | (lambda (orig-x) | |
| 2098 | (syntax-case orig-x () | |
| 2099 | ((_ ((var init . step) ...) (e0 e1 ...) c ...) | |
| 2100 | (with-syntax (((step ...) | |
| 2101 | (map (lambda (v s) | |
| 2102 | (syntax-case s () | |
| 2103 | (() v) | |
| 2104 | ((e) (syntax e)) | |
| 2105 | (_ (syntax-error orig-x)))) | |
| 2106 | (syntax (var ...)) | |
| 2107 | (syntax (step ...))))) | |
| 2108 | (syntax-case (syntax (e1 ...)) () | |
| 2109 | (() (syntax (let doloop ((var init) ...) | |
| 2110 | (if (not e0) | |
| 2111 | (begin c ... (doloop step ...)))))) | |
| 2112 | ((e1 e2 ...) | |
| 2113 | (syntax (let doloop ((var init) ...) | |
| 2114 | (if e0 | |
| 2115 | (begin e1 e2 ...) | |
| 2116 | (begin c ... (doloop step ...)))))))))))) | |
| 2117 | ||
| 2118 | (define-syntax quasiquote | |
| 2119 | (letrec | |
| 2120 | ((quasicons | |
| 2121 | (lambda (x y) | |
| 2122 | (with-syntax ((x x) (y y)) | |
| 2123 | (syntax-case (syntax y) (quote list) | |
| 2124 | ((quote dy) | |
| 2125 | (syntax-case (syntax x) (quote) | |
| 2126 | ((quote dx) (syntax (quote (dx . dy)))) | |
| 2127 | (_ (if (null? (syntax dy)) | |
| 2128 | (syntax (list x)) | |
| 2129 | (syntax (cons x y)))))) | |
| 2130 | ((list . stuff) (syntax (list x . stuff))) | |
| 2131 | (else (syntax (cons x y))))))) | |
| 2132 | (quasiappend | |
| 2133 | (lambda (x y) | |
| 2134 | (with-syntax ((x x) (y y)) | |
| 2135 | (syntax-case (syntax y) (quote) | |
| 2136 | ((quote ()) (syntax x)) | |
| 2137 | (_ (syntax (append x y))))))) | |
| 2138 | (quasivector | |
| 2139 | (lambda (x) | |
| 2140 | (with-syntax ((x x)) | |
| 2141 | (syntax-case (syntax x) (quote list) | |
| 2142 | ((quote (x ...)) (syntax (quote #(x ...)))) | |
| 2143 | ((list x ...) (syntax (vector x ...))) | |
| 2144 | (_ (syntax (list->vector x))))))) | |
| 2145 | (quasi | |
| 2146 | (lambda (p lev) | |
| 2147 | (syntax-case p (unquote unquote-splicing quasiquote) | |
| 2148 | ((unquote p) | |
| 2149 | (if (= lev 0) | |
| 2150 | (syntax p) | |
| 2151 | (quasicons (syntax (quote unquote)) | |
| 2152 | (quasi (syntax (p)) (- lev 1))))) | |
| 2153 | (((unquote-splicing p) . q) | |
| 2154 | (if (= lev 0) | |
| 2155 | (quasiappend (syntax p) (quasi (syntax q) lev)) | |
| 2156 | (quasicons (quasicons (syntax (quote unquote-splicing)) | |
| 2157 | (quasi (syntax (p)) (- lev 1))) | |
| 2158 | (quasi (syntax q) lev)))) | |
| 2159 | ((quasiquote p) | |
| 2160 | (quasicons (syntax (quote quasiquote)) | |
| 2161 | (quasi (syntax (p)) (+ lev 1)))) | |
| 2162 | ((p . q) | |
| 2163 | (quasicons (quasi (syntax p) lev) (quasi (syntax q) lev))) | |
| 2164 | (#(x ...) (quasivector (quasi (syntax (x ...)) lev))) | |
| 2165 | (p (syntax (quote p))))))) | |
| 2166 | (lambda (x) | |
| 2167 | (syntax-case x () | |
| 2168 | ((_ e) (quasi (syntax e) 0)))))) | |
| 2169 | ||
| 2170 | (define-syntax include | |
| 2171 | (lambda (x) | |
| 2172 | (define read-file | |
| 2173 | (lambda (fn k) | |
| 2174 | (let ((p (open-input-file fn))) | |
| 2175 | (let f ((x (read p))) | |
| 2176 | (if (eof-object? x) | |
| 2177 | (begin (close-input-port p) '()) | |
| 2178 | (cons (datum->syntax-object k x) | |
| 2179 | (f (read p)))))))) | |
| 2180 | (syntax-case x () | |
| 2181 | ((k filename) | |
| 2182 | (let ((fn (syntax-object->datum (syntax filename)))) | |
| 2183 | (with-syntax (((exp ...) (read-file fn (syntax k)))) | |
| 2184 | (syntax (begin exp ...)))))))) | |
| 2185 | ||
| 2186 | (define-syntax unquote | |
| 2187 | (lambda (x) | |
| 2188 | (syntax-case x () | |
| 2189 | ((_ e) | |
| 2190 | (error 'unquote | |
| 2191 | "expression ,~s not valid outside of quasiquote" | |
| 2192 | (syntax-object->datum (syntax e))))))) | |
| 2193 | ||
| 2194 | (define-syntax unquote-splicing | |
| 2195 | (lambda (x) | |
| 2196 | (syntax-case x () | |
| 2197 | ((_ e) | |
| 2198 | (error 'unquote-splicing | |
| 2199 | "expression ,@~s not valid outside of quasiquote" | |
| 2200 | (syntax-object->datum (syntax e))))))) | |
| 2201 | ||
| 2202 | (define-syntax case | |
| 2203 | (lambda (x) | |
| 2204 | (syntax-case x () | |
| 2205 | ((_ e m1 m2 ...) | |
| 2206 | (with-syntax | |
| 2207 | ((body (let f ((clause (syntax m1)) (clauses (syntax (m2 ...)))) | |
| 2208 | (if (null? clauses) | |
| 2209 | (syntax-case clause (else) | |
| 2210 | ((else e1 e2 ...) (syntax (begin e1 e2 ...))) | |
| 2211 | (((k ...) e1 e2 ...) | |
| 2212 | (syntax (if (memv t '(k ...)) (begin e1 e2 ...)))) | |
| 2213 | (_ (syntax-error x))) | |
| 2214 | (with-syntax ((rest (f (car clauses) (cdr clauses)))) | |
| 2215 | (syntax-case clause (else) | |
| 2216 | (((k ...) e1 e2 ...) | |
| 2217 | (syntax (if (memv t '(k ...)) | |
| 2218 | (begin e1 e2 ...) | |
| 2219 | rest))) | |
| 2220 | (_ (syntax-error x)))))))) | |
| 2221 | (syntax (let ((t e)) body))))))) | |
| 2222 | ||
| 2223 | (define-syntax identifier-syntax | |
| 2224 | (lambda (x) | |
| 2225 | (syntax-case x () | |
| 2226 | ((_ e) | |
| 2227 | (syntax | |
| 2228 | (lambda (x) | |
| 2229 | (syntax-case x () | |
| 2230 | (id | |
| 2231 | (identifier? (syntax id)) | |
| 2232 | (syntax e)) | |
| 2233 | ((_ x (... ...)) | |
| 2234 | (syntax (e x (... ...))))))))))) | |
| 2235 |