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1 | ;;;; -*-scheme-*- |
2 | ;;;; | |
05a5e5d6 | 3 | ;;;; Copyright (C) 2001, 2003, 2006, 2009, 2010, 2011 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 | |
53befeb7 | 8 | ;;;; version 3 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 | 21 | ;;; Portable implementation of syntax-case |
565c8e30 | 22 | ;;; Originally extracted from Chez Scheme Version 5.9f |
a63812a2 JB |
23 | ;;; Authors: R. Kent Dybvig, Oscar Waddell, Bob Hieb, Carl Bruggeman |
24 | ||
25 | ;;; Copyright (c) 1992-1997 Cadence Research Systems | |
26 | ;;; Permission to copy this software, in whole or in part, to use this | |
27 | ;;; software for any lawful purpose, and to redistribute this software | |
28 | ;;; is granted subject to the restriction that all copies made of this | |
29 | ;;; software must include this copyright notice in full. This software | |
30 | ;;; is provided AS IS, with NO WARRANTY, EITHER EXPRESS OR IMPLIED, | |
31 | ;;; INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY | |
32 | ;;; OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL THE | |
33 | ;;; AUTHORS BE LIABLE FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES OF ANY | |
34 | ;;; NATURE WHATSOEVER. | |
35 | ||
565c8e30 AW |
36 | ;;; Modified by Mikael Djurfeldt <djurfeldt@nada.kth.se> according |
37 | ;;; to the ChangeLog distributed in the same directory as this file: | |
38 | ;;; 1997-08-19, 1997-09-03, 1997-09-10, 2000-08-13, 2000-08-24, | |
39 | ;;; 2000-09-12, 2001-03-08 | |
40 | ||
41 | ;;; Modified by Andy Wingo <wingo@pobox.com> according to the Git | |
42 | ;;; revision control logs corresponding to this file: 2009, 2010. | |
a63812a2 JB |
43 | |
44 | ||
8a73a6d2 | 45 | ;;; This file defines the syntax-case expander, macroexpand, and a set |
a63812a2 JB |
46 | ;;; of associated syntactic forms and procedures. Of these, the |
47 | ;;; following are documented in The Scheme Programming Language, | |
565c8e30 AW |
48 | ;;; Fourth Edition (R. Kent Dybvig, MIT Press, 2009), and in the |
49 | ;;; R6RS: | |
a63812a2 JB |
50 | ;;; |
51 | ;;; bound-identifier=? | |
22225fc1 | 52 | ;;; datum->syntax |
a63812a2 JB |
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 | |
22225fc1 | 63 | ;;; syntax->datum |
a63812a2 JB |
64 | ;;; syntax-rules |
65 | ;;; with-syntax | |
66 | ;;; | |
565c8e30 AW |
67 | ;;; Additionally, the expander provides definitions for a number of core |
68 | ;;; Scheme syntactic bindings, such as `let', `lambda', and the like. | |
a63812a2 JB |
69 | |
70 | ;;; The remaining exports are listed below: | |
71 | ;;; | |
8a73a6d2 AW |
72 | ;;; (macroexpand datum) |
73 | ;;; if datum represents a valid expression, macroexpand returns an | |
a63812a2 JB |
74 | ;;; expanded version of datum in a core language that includes no |
75 | ;;; syntactic abstractions. The core language includes begin, | |
76 | ;;; define, if, lambda, letrec, quote, and set!. | |
77 | ;;; (eval-when situations expr ...) | |
78 | ;;; conditionally evaluates expr ... at compile-time or run-time | |
79 | ;;; depending upon situations (see the Chez Scheme System Manual, | |
80 | ;;; Revision 3, for a complete description) | |
e4721dde | 81 | ;;; (syntax-violation who message form [subform]) |
a63812a2 | 82 | ;;; used to report errors found during expansion |
5f1a2fb1 | 83 | ;;; ($sc-dispatch e p) |
a63812a2 JB |
84 | ;;; used by expanded code to handle syntax-case matching |
85 | ||
565c8e30 AW |
86 | ;;; This file is shipped along with an expanded version of itself, |
87 | ;;; psyntax-pp.scm, which is loaded when psyntax.scm has not yet been | |
88 | ;;; compiled. In this way, psyntax bootstraps off of an expanded | |
89 | ;;; version of itself. | |
90 | ||
91 | ;;; This implementation of the expander sometimes uses syntactic | |
92 | ;;; abstractions when procedural abstractions would suffice. For | |
93 | ;;; example, we define top-wrap and top-marked? as | |
a63812a2 | 94 | ;;; |
a63812a2 JB |
95 | ;;; (define-syntax top-wrap (identifier-syntax '((top)))) |
96 | ;;; (define-syntax top-marked? | |
97 | ;;; (syntax-rules () | |
98 | ;;; ((_ w) (memq 'top (wrap-marks w))))) | |
565c8e30 | 99 | ;;; |
a63812a2 | 100 | ;;; rather than |
565c8e30 | 101 | ;;; |
a63812a2 JB |
102 | ;;; (define top-wrap '((top))) |
103 | ;;; (define top-marked? | |
104 | ;;; (lambda (w) (memq 'top (wrap-marks w)))) | |
565c8e30 AW |
105 | ;;; |
106 | ;;; On the other hand, we don't do this consistently; we define | |
107 | ;;; make-wrap, wrap-marks, and wrap-subst simply as | |
108 | ;;; | |
a63812a2 JB |
109 | ;;; (define make-wrap cons) |
110 | ;;; (define wrap-marks car) | |
111 | ;;; (define wrap-subst cdr) | |
565c8e30 | 112 | ;;; |
a63812a2 JB |
113 | ;;; In Chez Scheme, the syntactic and procedural forms of these |
114 | ;;; abstractions are equivalent, since the optimizer consistently | |
565c8e30 AW |
115 | ;;; integrates constants and small procedures. This will be true of |
116 | ;;; Guile as well, once we implement a proper inliner. | |
a63812a2 | 117 | |
a63812a2 | 118 | |
565c8e30 | 119 | ;;; Implementation notes: |
a63812a2 JB |
120 | |
121 | ;;; Objects with no standard print syntax, including objects containing | |
122 | ;;; cycles and syntax object, are allowed in quoted data as long as they | |
22225fc1 | 123 | ;;; are contained within a syntax form or produced by datum->syntax. |
a63812a2 JB |
124 | ;;; Such objects are never copied. |
125 | ||
126 | ;;; All identifiers that don't have macro definitions and are not bound | |
565c8e30 | 127 | ;;; lexically are assumed to be global variables. |
a63812a2 JB |
128 | |
129 | ;;; Top-level definitions of macro-introduced identifiers are allowed. | |
130 | ;;; This may not be appropriate for implementations in which the | |
131 | ;;; model is that bindings are created by definitions, as opposed to | |
132 | ;;; one in which initial values are assigned by definitions. | |
133 | ||
a63812a2 | 134 | ;;; Identifiers and syntax objects are implemented as vectors for |
565c8e30 | 135 | ;;; portability. As a result, it is possible to "forge" syntax objects. |
a63812a2 | 136 | |
565c8e30 AW |
137 | ;;; The implementation of generate-temporaries assumes that it is |
138 | ;;; possible to generate globally unique symbols (gensyms). | |
a63812a2 | 139 | |
565c8e30 AW |
140 | ;;; The source location associated with incoming expressions is tracked |
141 | ;;; via the source-properties mechanism, a weak map from expression to | |
142 | ;;; source information. At times the source is separated from the | |
143 | ;;; expression; see the note below about "efficiency and confusion". | |
a96434cc | 144 | |
a63812a2 JB |
145 | |
146 | ;;; Bootstrapping: | |
147 | ||
148 | ;;; When changing syntax-object representations, it is necessary to support | |
149 | ;;; both old and new syntax-object representations in id-var-name. It | |
150 | ;;; should be sufficient to recognize old representations and treat | |
151 | ;;; them as not lexically bound. | |
152 | ||
153 | ||
154 | ||
9c35c579 AW |
155 | (eval-when (compile) |
156 | (set-current-module (resolve-module '(guile)))) | |
157 | ||
a63812a2 | 158 | (let () |
8fad25c2 AW |
159 | ;; Private version of and-map that handles multiple lists. |
160 | (define and-map* | |
161 | (lambda (f first . rest) | |
162 | (or (null? first) | |
163 | (if (null? rest) | |
164 | (let andmap ((first first)) | |
165 | (let ((x (car first)) (first (cdr first))) | |
166 | (if (null? first) | |
167 | (f x) | |
168 | (and (f x) (andmap first))))) | |
169 | (let andmap ((first first) (rest rest)) | |
170 | (let ((x (car first)) | |
171 | (xr (map car rest)) | |
172 | (first (cdr first)) | |
173 | (rest (map cdr rest))) | |
174 | (if (null? first) | |
175 | (apply f x xr) | |
176 | (and (apply f x xr) (andmap first rest))))))))) | |
177 | ||
178 | (define-syntax define-expansion-constructors | |
179 | (lambda (x) | |
180 | (syntax-case x () | |
181 | ((_) | |
182 | (let lp ((n 0) (out '())) | |
183 | (if (< n (vector-length %expanded-vtables)) | |
184 | (lp (1+ n) | |
185 | (let* ((vtable (vector-ref %expanded-vtables n)) | |
186 | (stem (struct-ref vtable (+ vtable-offset-user 0))) | |
187 | (fields (struct-ref vtable (+ vtable-offset-user 2))) | |
188 | (sfields (map (lambda (f) (datum->syntax x f)) fields)) | |
189 | (ctor (datum->syntax x (symbol-append 'make- stem)))) | |
190 | (cons #`(define (#,ctor #,@sfields) | |
191 | (make-struct (vector-ref %expanded-vtables #,n) 0 | |
192 | #,@sfields)) | |
193 | out))) | |
194 | #`(begin #,@(reverse out)))))))) | |
195 | ||
196 | (define-syntax define-expansion-accessors | |
197 | (lambda (x) | |
198 | (syntax-case x () | |
199 | ((_ stem field ...) | |
200 | (let lp ((n 0)) | |
201 | (let ((vtable (vector-ref %expanded-vtables n)) | |
202 | (stem (syntax->datum #'stem))) | |
203 | (if (eq? (struct-ref vtable (+ vtable-offset-user 0)) stem) | |
204 | #`(begin | |
205 | (define (#,(datum->syntax x (symbol-append stem '?)) x) | |
206 | (and (struct? x) | |
207 | (eq? (struct-vtable x) | |
208 | (vector-ref %expanded-vtables #,n)))) | |
209 | #,@(map | |
210 | (lambda (f) | |
211 | (let ((get (datum->syntax x (symbol-append stem '- f))) | |
212 | (set (datum->syntax x (symbol-append 'set- stem '- f '!))) | |
213 | (idx (list-index (struct-ref vtable | |
214 | (+ vtable-offset-user 2)) | |
215 | f))) | |
216 | #`(begin | |
217 | (define (#,get x) | |
218 | (struct-ref x #,idx)) | |
219 | (define (#,set x v) | |
220 | (struct-set! x #,idx v))))) | |
221 | (syntax->datum #'(field ...)))) | |
222 | (lp (1+ n))))))))) | |
223 | ||
224 | (define-syntax define-structure | |
225 | (lambda (x) | |
226 | (define construct-name | |
227 | (lambda (template-identifier . args) | |
228 | (datum->syntax | |
229 | template-identifier | |
230 | (string->symbol | |
a63812a2 JB |
231 | (apply string-append |
232 | (map (lambda (x) | |
233 | (if (string? x) | |
234 | x | |
22225fc1 | 235 | (symbol->string (syntax->datum x)))) |
a63812a2 | 236 | args)))))) |
8fad25c2 AW |
237 | (syntax-case x () |
238 | ((_ (name id1 ...)) | |
239 | (and-map identifier? #'(name id1 ...)) | |
240 | (with-syntax | |
241 | ((constructor (construct-name #'name "make-" #'name)) | |
242 | (predicate (construct-name #'name #'name "?")) | |
243 | ((access ...) | |
244 | (map (lambda (x) (construct-name x #'name "-" x)) | |
245 | #'(id1 ...))) | |
246 | ((assign ...) | |
247 | (map (lambda (x) | |
248 | (construct-name x "set-" #'name "-" x "!")) | |
249 | #'(id1 ...))) | |
250 | (structure-length | |
251 | (+ (length #'(id1 ...)) 1)) | |
252 | ((index ...) | |
253 | (let f ((i 1) (ids #'(id1 ...))) | |
254 | (if (null? ids) | |
255 | '() | |
256 | (cons i (f (+ i 1) (cdr ids))))))) | |
257 | #'(begin | |
258 | (define constructor | |
259 | (lambda (id1 ...) | |
260 | (vector 'name id1 ... ))) | |
261 | (define predicate | |
262 | (lambda (x) | |
263 | (and (vector? x) | |
264 | (= (vector-length x) structure-length) | |
265 | (eq? (vector-ref x 0) 'name)))) | |
266 | (define access | |
267 | (lambda (x) | |
268 | (vector-ref x index))) | |
269 | ... | |
270 | (define assign | |
271 | (lambda (x update) | |
272 | (vector-set! x index update))) | |
273 | ...)))))) | |
a63812a2 | 274 | |
8fad25c2 AW |
275 | (let () |
276 | (define-expansion-constructors) | |
277 | (define-expansion-accessors lambda meta) | |
278 | ||
279 | ;; hooks to nonportable run-time helpers | |
280 | (begin | |
281 | (define fx+ +) | |
282 | (define fx- -) | |
283 | (define fx= =) | |
284 | (define fx< <) | |
285 | ||
286 | (define top-level-eval-hook | |
287 | (lambda (x mod) | |
288 | (primitive-eval x))) | |
289 | ||
290 | (define local-eval-hook | |
291 | (lambda (x mod) | |
292 | (primitive-eval x))) | |
bdf7759c | 293 | |
8fad25c2 AW |
294 | (define-syntax gensym-hook |
295 | (syntax-rules () | |
296 | ((_) (gensym)))) | |
c3ae0ed4 | 297 | |
8fad25c2 AW |
298 | (define put-global-definition-hook |
299 | (lambda (symbol type val) | |
300 | (module-define! (current-module) | |
301 | symbol | |
302 | (make-syntax-transformer symbol type val)))) | |
e809758a | 303 | |
8fad25c2 AW |
304 | (define get-global-definition-hook |
305 | (lambda (symbol module) | |
306 | (if (and (not module) (current-module)) | |
307 | (warn "module system is booted, we should have a module" symbol)) | |
308 | (let ((v (module-variable (if module | |
309 | (resolve-module (cdr module)) | |
310 | (current-module)) | |
311 | symbol))) | |
312 | (and v (variable-bound? v) | |
313 | (let ((val (variable-ref v))) | |
314 | (and (macro? val) (macro-type val) | |
315 | (cons (macro-type val) | |
316 | (macro-binding val))))))))) | |
317 | ||
318 | ||
319 | (define (decorate-source e s) | |
320 | (if (and (pair? e) s) | |
321 | (set-source-properties! e s)) | |
322 | e) | |
323 | ||
324 | (define (maybe-name-value! name val) | |
325 | (if (lambda? val) | |
326 | (let ((meta (lambda-meta val))) | |
327 | (if (not (assq 'name meta)) | |
328 | (set-lambda-meta! val (acons 'name name meta)))))) | |
329 | ||
330 | ;; output constructors | |
331 | (define build-void | |
332 | (lambda (source) | |
333 | (make-void source))) | |
334 | ||
335 | (define build-application | |
336 | (lambda (source fun-exp arg-exps) | |
337 | (make-application source fun-exp arg-exps))) | |
bdf7759c | 338 | |
8fad25c2 AW |
339 | (define build-conditional |
340 | (lambda (source test-exp then-exp else-exp) | |
341 | (make-conditional source test-exp then-exp else-exp))) | |
bdf7759c | 342 | |
8fad25c2 AW |
343 | (define build-dynlet |
344 | (lambda (source fluids vals body) | |
345 | (make-dynlet source fluids vals body))) | |
bdf7759c | 346 | |
8fad25c2 AW |
347 | (define build-lexical-reference |
348 | (lambda (type source name var) | |
349 | (make-lexical-ref source name var))) | |
bdf7759c | 350 | |
8fad25c2 AW |
351 | (define build-lexical-assignment |
352 | (lambda (source name var exp) | |
353 | (maybe-name-value! name exp) | |
354 | (make-lexical-set source name var exp))) | |
bdf7759c | 355 | |
8fad25c2 AW |
356 | (define (analyze-variable mod var modref-cont bare-cont) |
357 | (if (not mod) | |
358 | (bare-cont var) | |
359 | (let ((kind (car mod)) | |
360 | (mod (cdr mod))) | |
361 | (case kind | |
362 | ((public) (modref-cont mod var #t)) | |
363 | ((private) (if (not (equal? mod (module-name (current-module)))) | |
364 | (modref-cont mod var #f) | |
365 | (bare-cont var))) | |
366 | ((bare) (bare-cont var)) | |
367 | ((hygiene) (if (and (not (equal? mod (module-name (current-module)))) | |
368 | (module-variable (resolve-module mod) var)) | |
369 | (modref-cont mod var #f) | |
370 | (bare-cont var))) | |
371 | (else (syntax-violation #f "bad module kind" var mod)))))) | |
372 | ||
373 | (define build-global-reference | |
374 | (lambda (source var mod) | |
375 | (analyze-variable | |
376 | mod var | |
377 | (lambda (mod var public?) | |
378 | (make-module-ref source mod var public?)) | |
379 | (lambda (var) | |
380 | (make-toplevel-ref source var))))) | |
381 | ||
382 | (define build-global-assignment | |
383 | (lambda (source var exp mod) | |
384 | (maybe-name-value! var exp) | |
385 | (analyze-variable | |
386 | mod var | |
387 | (lambda (mod var public?) | |
388 | (make-module-set source mod var public? exp)) | |
389 | (lambda (var) | |
390 | (make-toplevel-set source var exp))))) | |
391 | ||
392 | (define build-global-definition | |
393 | (lambda (source var exp) | |
394 | (maybe-name-value! var exp) | |
395 | (make-toplevel-define source var exp))) | |
396 | ||
397 | (define build-simple-lambda | |
398 | (lambda (src req rest vars meta exp) | |
399 | (make-lambda src | |
400 | meta | |
401 | ;; hah, a case in which kwargs would be nice. | |
402 | (make-lambda-case | |
403 | ;; src req opt rest kw inits vars body else | |
404 | src req #f rest #f '() vars exp #f)))) | |
405 | ||
406 | (define build-case-lambda | |
407 | (lambda (src meta body) | |
408 | (make-lambda src meta body))) | |
409 | ||
410 | (define build-lambda-case | |
411 | ;; req := (name ...) | |
412 | ;; opt := (name ...) | #f | |
413 | ;; rest := name | #f | |
414 | ;; kw := (allow-other-keys? (keyword name var) ...) | #f | |
415 | ;; inits: (init ...) | |
416 | ;; vars: (sym ...) | |
417 | ;; vars map to named arguments in the following order: | |
418 | ;; required, optional (positional), rest, keyword. | |
419 | ;; the body of a lambda: anything, already expanded | |
420 | ;; else: lambda-case | #f | |
421 | (lambda (src req opt rest kw inits vars body else-case) | |
422 | (make-lambda-case src req opt rest kw inits vars body else-case))) | |
423 | ||
424 | (define build-primref | |
425 | (lambda (src name) | |
426 | (if (equal? (module-name (current-module)) '(guile)) | |
427 | (make-toplevel-ref src name) | |
428 | (make-module-ref src '(guile) name #f)))) | |
429 | ||
430 | (define (build-data src exp) | |
431 | (make-const src exp)) | |
432 | ||
433 | (define build-sequence | |
434 | (lambda (src exps) | |
435 | (if (null? (cdr exps)) | |
436 | (car exps) | |
437 | (make-sequence src exps)))) | |
438 | ||
439 | (define build-let | |
440 | (lambda (src ids vars val-exps body-exp) | |
441 | (for-each maybe-name-value! ids val-exps) | |
442 | (if (null? vars) | |
443 | body-exp | |
444 | (make-let src ids vars val-exps body-exp)))) | |
445 | ||
446 | (define build-named-let | |
447 | (lambda (src ids vars val-exps body-exp) | |
448 | (let ((f (car vars)) | |
449 | (f-name (car ids)) | |
450 | (vars (cdr vars)) | |
451 | (ids (cdr ids))) | |
452 | (let ((proc (build-simple-lambda src ids #f vars '() body-exp))) | |
453 | (maybe-name-value! f-name proc) | |
22cf27c8 | 454 | (for-each maybe-name-value! ids val-exps) |
8fad25c2 AW |
455 | (make-letrec |
456 | src #f | |
457 | (list f-name) (list f) (list proc) | |
458 | (build-application src (build-lexical-reference 'fun src f-name f) | |
459 | val-exps)))))) | |
460 | ||
461 | (define build-letrec | |
462 | (lambda (src in-order? ids vars val-exps body-exp) | |
463 | (if (null? vars) | |
464 | body-exp | |
465 | (begin | |
466 | (for-each maybe-name-value! ids val-exps) | |
467 | (make-letrec src in-order? ids vars val-exps body-exp))))) | |
468 | ||
469 | ||
470 | ;; FIXME: use a faster gensym | |
471 | (define-syntax build-lexical-var | |
472 | (syntax-rules () | |
473 | ((_ src id) (gensym (string-append (symbol->string id) " "))))) | |
bdf7759c | 474 | |
8fad25c2 | 475 | (define-structure (syntax-object expression wrap module)) |
a63812a2 | 476 | |
8fad25c2 | 477 | (define-syntax no-source (identifier-syntax #f)) |
a63812a2 | 478 | |
8fad25c2 AW |
479 | (define source-annotation |
480 | (lambda (x) | |
481 | (cond | |
482 | ((syntax-object? x) | |
483 | (source-annotation (syntax-object-expression x))) | |
484 | ((pair? x) (let ((props (source-properties x))) | |
485 | (if (pair? props) | |
486 | props | |
487 | #f))) | |
488 | (else #f)))) | |
a63812a2 | 489 | |
8fad25c2 AW |
490 | (define-syntax arg-check |
491 | (syntax-rules () | |
492 | ((_ pred? e who) | |
493 | (let ((x e)) | |
494 | (if (not (pred? x)) (syntax-violation who "invalid argument" x)))))) | |
495 | ||
496 | ;; compile-time environments | |
497 | ||
498 | ;; wrap and environment comprise two level mapping. | |
499 | ;; wrap : id --> label | |
500 | ;; env : label --> <element> | |
501 | ||
502 | ;; environments are represented in two parts: a lexical part and a global | |
503 | ;; part. The lexical part is a simple list of associations from labels | |
504 | ;; to bindings. The global part is implemented by | |
505 | ;; {put,get}-global-definition-hook and associates symbols with | |
506 | ;; bindings. | |
507 | ||
508 | ;; global (assumed global variable) and displaced-lexical (see below) | |
509 | ;; do not show up in any environment; instead, they are fabricated by | |
510 | ;; lookup when it finds no other bindings. | |
511 | ||
512 | ;; <environment> ::= ((<label> . <binding>)*) | |
513 | ||
514 | ;; identifier bindings include a type and a value | |
515 | ||
516 | ;; <binding> ::= (macro . <procedure>) macros | |
517 | ;; (core . <procedure>) core forms | |
518 | ;; (module-ref . <procedure>) @ or @@ | |
519 | ;; (begin) begin | |
520 | ;; (define) define | |
521 | ;; (define-syntax) define-syntax | |
522 | ;; (local-syntax . rec?) let-syntax/letrec-syntax | |
523 | ;; (eval-when) eval-when | |
4c2e13e5 | 524 | ;; (syntax . (<var> . <level>)) pattern variables |
8fad25c2 AW |
525 | ;; (global) assumed global variable |
526 | ;; (lexical . <var>) lexical variables | |
527 | ;; (displaced-lexical) displaced lexicals | |
528 | ;; <level> ::= <nonnegative integer> | |
529 | ;; <var> ::= variable returned by build-lexical-var | |
530 | ||
531 | ;; a macro is a user-defined syntactic-form. a core is a system-defined | |
532 | ;; syntactic form. begin, define, define-syntax, and eval-when are | |
533 | ;; treated specially since they are sensitive to whether the form is | |
534 | ;; at top-level and (except for eval-when) can denote valid internal | |
535 | ;; definitions. | |
536 | ||
537 | ;; a pattern variable is a variable introduced by syntax-case and can | |
538 | ;; be referenced only within a syntax form. | |
539 | ||
540 | ;; any identifier for which no top-level syntax definition or local | |
541 | ;; binding of any kind has been seen is assumed to be a global | |
542 | ;; variable. | |
543 | ||
544 | ;; a lexical variable is a lambda- or letrec-bound variable. | |
545 | ||
546 | ;; a displaced-lexical identifier is a lexical identifier removed from | |
547 | ;; it's scope by the return of a syntax object containing the identifier. | |
548 | ;; a displaced lexical can also appear when a letrec-syntax-bound | |
549 | ;; keyword is referenced on the rhs of one of the letrec-syntax clauses. | |
550 | ;; a displaced lexical should never occur with properly written macros. | |
551 | ||
552 | (define-syntax make-binding | |
553 | (syntax-rules (quote) | |
554 | ((_ type value) (cons type value)) | |
555 | ((_ 'type) '(type)) | |
556 | ((_ type) (cons type '())))) | |
cf45ff03 AW |
557 | (define-syntax binding-type |
558 | (syntax-rules () | |
559 | ((_ x) (car x)))) | |
560 | (define-syntax binding-value | |
561 | (syntax-rules () | |
562 | ((_ x) (cdr x)))) | |
8fad25c2 AW |
563 | |
564 | (define-syntax null-env (identifier-syntax '())) | |
565 | ||
566 | (define extend-env | |
567 | (lambda (labels bindings r) | |
568 | (if (null? labels) | |
569 | r | |
570 | (extend-env (cdr labels) (cdr bindings) | |
571 | (cons (cons (car labels) (car bindings)) r))))) | |
c3ae0ed4 | 572 | |
8fad25c2 AW |
573 | (define extend-var-env |
574 | ;; variant of extend-env that forms "lexical" binding | |
575 | (lambda (labels vars r) | |
576 | (if (null? labels) | |
577 | r | |
578 | (extend-var-env (cdr labels) (cdr vars) | |
579 | (cons (cons (car labels) (make-binding 'lexical (car vars))) r))))) | |
580 | ||
581 | ;; we use a "macros only" environment in expansion of local macro | |
582 | ;; definitions so that their definitions can use local macros without | |
583 | ;; attempting to use other lexical identifiers. | |
584 | (define macros-only-env | |
585 | (lambda (r) | |
586 | (if (null? r) | |
587 | '() | |
588 | (let ((a (car r))) | |
589 | (if (eq? (cadr a) 'macro) | |
590 | (cons a (macros-only-env (cdr r))) | |
591 | (macros-only-env (cdr r))))))) | |
592 | ||
593 | (define lookup | |
594 | ;; x may be a label or a symbol | |
595 | ;; although symbols are usually global, we check the environment first | |
596 | ;; anyway because a temporary binding may have been established by | |
597 | ;; fluid-let-syntax | |
598 | (lambda (x r mod) | |
599 | (cond | |
600 | ((assq x r) => cdr) | |
601 | ((symbol? x) | |
602 | (or (get-global-definition-hook x mod) (make-binding 'global))) | |
603 | (else (make-binding 'displaced-lexical))))) | |
a63812a2 | 604 | |
8fad25c2 AW |
605 | (define global-extend |
606 | (lambda (type sym val) | |
607 | (put-global-definition-hook sym type val))) | |
608 | ||
609 | ||
610 | ;; Conceptually, identifiers are always syntax objects. Internally, | |
611 | ;; however, the wrap is sometimes maintained separately (a source of | |
612 | ;; efficiency and confusion), so that symbols are also considered | |
613 | ;; identifiers by id?. Externally, they are always wrapped. | |
614 | ||
615 | (define nonsymbol-id? | |
616 | (lambda (x) | |
617 | (and (syntax-object? x) | |
618 | (symbol? (syntax-object-expression x))))) | |
619 | ||
620 | (define id? | |
621 | (lambda (x) | |
622 | (cond | |
623 | ((symbol? x) #t) | |
624 | ((syntax-object? x) (symbol? (syntax-object-expression x))) | |
625 | (else #f)))) | |
626 | ||
627 | (define-syntax id-sym-name | |
628 | (syntax-rules () | |
629 | ((_ e) | |
630 | (let ((x e)) | |
631 | (if (syntax-object? x) | |
632 | (syntax-object-expression x) | |
633 | x))))) | |
634 | ||
635 | (define id-sym-name&marks | |
636 | (lambda (x w) | |
637 | (if (syntax-object? x) | |
638 | (values | |
c3ae0ed4 | 639 | (syntax-object-expression x) |
8fad25c2 AW |
640 | (join-marks (wrap-marks w) (wrap-marks (syntax-object-wrap x)))) |
641 | (values x (wrap-marks w))))) | |
c3ae0ed4 | 642 | |
8fad25c2 AW |
643 | ;; syntax object wraps |
644 | ||
645 | ;; <wrap> ::= ((<mark> ...) . (<subst> ...)) | |
646 | ;; <subst> ::= <shift> | <subs> | |
647 | ;; <subs> ::= #(<old name> <label> (<mark> ...)) | |
648 | ;; <shift> ::= positive fixnum | |
649 | ||
381ccb0b AW |
650 | (define-syntax make-wrap (identifier-syntax cons)) |
651 | (define-syntax wrap-marks (identifier-syntax car)) | |
652 | (define-syntax wrap-subst (identifier-syntax cdr)) | |
8fad25c2 AW |
653 | |
654 | (define-syntax subst-rename? (identifier-syntax vector?)) | |
655 | (define-syntax rename-old (syntax-rules () ((_ x) (vector-ref x 0)))) | |
656 | (define-syntax rename-new (syntax-rules () ((_ x) (vector-ref x 1)))) | |
657 | (define-syntax rename-marks (syntax-rules () ((_ x) (vector-ref x 2)))) | |
658 | (define-syntax make-rename | |
659 | (syntax-rules () | |
660 | ((_ old new marks) (vector old new marks)))) | |
661 | ||
662 | ;; labels must be comparable with "eq?", have read-write invariance, | |
663 | ;; and distinct from symbols. | |
664 | (define gen-label | |
665 | (lambda () (symbol->string (gensym "i")))) | |
666 | ||
667 | (define gen-labels | |
668 | (lambda (ls) | |
669 | (if (null? ls) | |
670 | '() | |
671 | (cons (gen-label) (gen-labels (cdr ls)))))) | |
672 | ||
673 | (define-structure (ribcage symnames marks labels)) | |
674 | ||
675 | (define-syntax empty-wrap (identifier-syntax '(()))) | |
676 | ||
677 | (define-syntax top-wrap (identifier-syntax '((top)))) | |
678 | ||
679 | (define-syntax top-marked? | |
680 | (syntax-rules () | |
681 | ((_ w) (memq 'top (wrap-marks w))))) | |
682 | ||
683 | ;; Marks must be comparable with "eq?" and distinct from pairs and | |
684 | ;; the symbol top. We do not use integers so that marks will remain | |
685 | ;; unique even across file compiles. | |
686 | ||
687 | (define-syntax the-anti-mark (identifier-syntax #f)) | |
688 | ||
689 | (define anti-mark | |
690 | (lambda (w) | |
691 | (make-wrap (cons the-anti-mark (wrap-marks w)) | |
692 | (cons 'shift (wrap-subst w))))) | |
693 | ||
694 | (define-syntax new-mark | |
695 | (syntax-rules () | |
696 | ((_) (gensym "m")))) | |
697 | ||
698 | ;; make-empty-ribcage and extend-ribcage maintain list-based ribcages for | |
699 | ;; internal definitions, in which the ribcages are built incrementally | |
700 | (define-syntax make-empty-ribcage | |
701 | (syntax-rules () | |
702 | ((_) (make-ribcage '() '() '())))) | |
703 | ||
704 | (define extend-ribcage! | |
705 | ;; must receive ids with complete wraps | |
706 | (lambda (ribcage id label) | |
707 | (set-ribcage-symnames! ribcage | |
708 | (cons (syntax-object-expression id) | |
709 | (ribcage-symnames ribcage))) | |
710 | (set-ribcage-marks! ribcage | |
711 | (cons (wrap-marks (syntax-object-wrap id)) | |
712 | (ribcage-marks ribcage))) | |
713 | (set-ribcage-labels! ribcage | |
714 | (cons label (ribcage-labels ribcage))))) | |
715 | ||
716 | ;; make-binding-wrap creates vector-based ribcages | |
717 | (define make-binding-wrap | |
718 | (lambda (ids labels w) | |
719 | (if (null? ids) | |
720 | w | |
c3ae0ed4 | 721 | (make-wrap |
8fad25c2 AW |
722 | (wrap-marks w) |
723 | (cons | |
724 | (let ((labelvec (list->vector labels))) | |
725 | (let ((n (vector-length labelvec))) | |
726 | (let ((symnamevec (make-vector n)) (marksvec (make-vector n))) | |
727 | (let f ((ids ids) (i 0)) | |
728 | (if (not (null? ids)) | |
729 | (call-with-values | |
730 | (lambda () (id-sym-name&marks (car ids) w)) | |
731 | (lambda (symname marks) | |
732 | (vector-set! symnamevec i symname) | |
733 | (vector-set! marksvec i marks) | |
734 | (f (cdr ids) (fx+ i 1)))))) | |
735 | (make-ribcage symnamevec marksvec labelvec)))) | |
736 | (wrap-subst w)))))) | |
737 | ||
738 | (define smart-append | |
739 | (lambda (m1 m2) | |
740 | (if (null? m2) | |
741 | m1 | |
742 | (append m1 m2)))) | |
743 | ||
744 | (define join-wraps | |
745 | (lambda (w1 w2) | |
746 | (let ((m1 (wrap-marks w1)) (s1 (wrap-subst w1))) | |
747 | (if (null? m1) | |
748 | (if (null? s1) | |
749 | w2 | |
750 | (make-wrap | |
751 | (wrap-marks w2) | |
752 | (smart-append s1 (wrap-subst w2)))) | |
753 | (make-wrap | |
754 | (smart-append m1 (wrap-marks w2)) | |
755 | (smart-append s1 (wrap-subst w2))))))) | |
756 | ||
757 | (define join-marks | |
758 | (lambda (m1 m2) | |
759 | (smart-append m1 m2))) | |
760 | ||
761 | (define same-marks? | |
762 | (lambda (x y) | |
763 | (or (eq? x y) | |
764 | (and (not (null? x)) | |
765 | (not (null? y)) | |
766 | (eq? (car x) (car y)) | |
767 | (same-marks? (cdr x) (cdr y)))))) | |
768 | ||
769 | (define id-var-name | |
770 | (lambda (id w) | |
771 | (define-syntax first | |
772 | (syntax-rules () | |
773 | ((_ e) (call-with-values (lambda () e) (lambda (x . ignore) x))))) | |
774 | (define search | |
775 | (lambda (sym subst marks) | |
776 | (if (null? subst) | |
777 | (values #f marks) | |
778 | (let ((fst (car subst))) | |
779 | (if (eq? fst 'shift) | |
780 | (search sym (cdr subst) (cdr marks)) | |
781 | (let ((symnames (ribcage-symnames fst))) | |
782 | (if (vector? symnames) | |
783 | (search-vector-rib sym subst marks symnames fst) | |
784 | (search-list-rib sym subst marks symnames fst)))))))) | |
785 | (define search-list-rib | |
786 | (lambda (sym subst marks symnames ribcage) | |
787 | (let f ((symnames symnames) (i 0)) | |
c3ae0ed4 | 788 | (cond |
8fad25c2 AW |
789 | ((null? symnames) (search sym (cdr subst) marks)) |
790 | ((and (eq? (car symnames) sym) | |
791 | (same-marks? marks (list-ref (ribcage-marks ribcage) i))) | |
792 | (values (list-ref (ribcage-labels ribcage) i) marks)) | |
793 | (else (f (cdr symnames) (fx+ i 1))))))) | |
794 | (define search-vector-rib | |
795 | (lambda (sym subst marks symnames ribcage) | |
796 | (let ((n (vector-length symnames))) | |
797 | (let f ((i 0)) | |
798 | (cond | |
799 | ((fx= i n) (search sym (cdr subst) marks)) | |
800 | ((and (eq? (vector-ref symnames i) sym) | |
801 | (same-marks? marks (vector-ref (ribcage-marks ribcage) i))) | |
802 | (values (vector-ref (ribcage-labels ribcage) i) marks)) | |
803 | (else (f (fx+ i 1)))))))) | |
804 | (cond | |
805 | ((symbol? id) | |
806 | (or (first (search id (wrap-subst w) (wrap-marks w))) id)) | |
807 | ((syntax-object? id) | |
808 | (let ((id (syntax-object-expression id)) | |
809 | (w1 (syntax-object-wrap id))) | |
810 | (let ((marks (join-marks (wrap-marks w) (wrap-marks w1)))) | |
811 | (call-with-values (lambda () (search id (wrap-subst w) marks)) | |
812 | (lambda (new-id marks) | |
813 | (or new-id | |
814 | (first (search id (wrap-subst w1) marks)) | |
815 | id)))))) | |
816 | (else (syntax-violation 'id-var-name "invalid id" id))))) | |
817 | ||
818 | ;; free-id=? must be passed fully wrapped ids since (free-id=? x y) | |
819 | ;; may be true even if (free-id=? (wrap x w) (wrap y w)) is not. | |
820 | ||
821 | (define free-id=? | |
822 | (lambda (i j) | |
823 | (and (eq? (id-sym-name i) (id-sym-name j)) ; accelerator | |
824 | (eq? (id-var-name i empty-wrap) (id-var-name j empty-wrap))))) | |
825 | ||
826 | ;; bound-id=? may be passed unwrapped (or partially wrapped) ids as | |
827 | ;; long as the missing portion of the wrap is common to both of the ids | |
828 | ;; since (bound-id=? x y) iff (bound-id=? (wrap x w) (wrap y w)) | |
829 | ||
830 | (define bound-id=? | |
831 | (lambda (i j) | |
832 | (if (and (syntax-object? i) (syntax-object? j)) | |
833 | (and (eq? (syntax-object-expression i) | |
834 | (syntax-object-expression j)) | |
835 | (same-marks? (wrap-marks (syntax-object-wrap i)) | |
836 | (wrap-marks (syntax-object-wrap j)))) | |
837 | (eq? i j)))) | |
838 | ||
839 | ;; "valid-bound-ids?" returns #t if it receives a list of distinct ids. | |
840 | ;; valid-bound-ids? may be passed unwrapped (or partially wrapped) ids | |
841 | ;; as long as the missing portion of the wrap is common to all of the | |
842 | ;; ids. | |
843 | ||
844 | (define valid-bound-ids? | |
845 | (lambda (ids) | |
846 | (and (let all-ids? ((ids ids)) | |
847 | (or (null? ids) | |
848 | (and (id? (car ids)) | |
849 | (all-ids? (cdr ids))))) | |
850 | (distinct-bound-ids? ids)))) | |
851 | ||
852 | ;; distinct-bound-ids? expects a list of ids and returns #t if there are | |
853 | ;; no duplicates. It is quadratic on the length of the id list; long | |
854 | ;; lists could be sorted to make it more efficient. distinct-bound-ids? | |
855 | ;; may be passed unwrapped (or partially wrapped) ids as long as the | |
856 | ;; missing portion of the wrap is common to all of the ids. | |
857 | ||
858 | (define distinct-bound-ids? | |
859 | (lambda (ids) | |
860 | (let distinct? ((ids ids)) | |
861 | (or (null? ids) | |
862 | (and (not (bound-id-member? (car ids) (cdr ids))) | |
863 | (distinct? (cdr ids))))))) | |
864 | ||
865 | (define bound-id-member? | |
866 | (lambda (x list) | |
867 | (and (not (null? list)) | |
868 | (or (bound-id=? x (car list)) | |
869 | (bound-id-member? x (cdr list)))))) | |
870 | ||
871 | ;; wrapping expressions and identifiers | |
872 | ||
873 | (define wrap | |
874 | (lambda (x w defmod) | |
875 | (cond | |
876 | ((and (null? (wrap-marks w)) (null? (wrap-subst w))) x) | |
877 | ((syntax-object? x) | |
878 | (make-syntax-object | |
879 | (syntax-object-expression x) | |
880 | (join-wraps w (syntax-object-wrap x)) | |
881 | (syntax-object-module x))) | |
882 | ((null? x) x) | |
883 | (else (make-syntax-object x w defmod))))) | |
884 | ||
885 | (define source-wrap | |
886 | (lambda (x w s defmod) | |
887 | (wrap (decorate-source x s) w defmod))) | |
888 | ||
889 | ;; expanding | |
890 | ||
891 | (define chi-sequence | |
892 | (lambda (body r w s mod) | |
893 | (build-sequence s | |
894 | (let dobody ((body body) (r r) (w w) (mod mod)) | |
895 | (if (null? body) | |
896 | '() | |
897 | (let ((first (chi (car body) r w mod))) | |
898 | (cons first (dobody (cdr body) r w mod)))))))) | |
899 | ||
900 | (define chi-top-sequence | |
901 | (lambda (body r w s m esew mod) | |
4c2e13e5 AW |
902 | (define (scan body r w s m esew mod exps) |
903 | (define-syntax eval-if-c&e | |
904 | (syntax-rules () | |
905 | ((_ m e mod) | |
906 | (let ((x e)) | |
907 | (if (eq? m 'c&e) (top-level-eval-hook x mod)) | |
908 | x)))) | |
909 | (cond | |
910 | ((null? body) | |
911 | ;; in reversed order | |
912 | exps) | |
913 | (else | |
914 | (call-with-values | |
915 | (lambda () | |
916 | (call-with-values | |
917 | (lambda () | |
918 | (let ((e (car body))) | |
919 | (syntax-type e r w (or (source-annotation e) s) #f mod #f))) | |
920 | (lambda (type value e w s mod) | |
921 | (case type | |
922 | ((begin-form) | |
923 | (syntax-case e () | |
924 | ((_) exps) | |
925 | ((_ e1 e2 ...) | |
926 | (scan #'(e1 e2 ...) r w s m esew mod exps)))) | |
927 | ((local-syntax-form) | |
928 | (chi-local-syntax value e r w s mod | |
929 | (lambda (body r w s mod) | |
930 | (scan body r w s m esew mod exps)))) | |
931 | ((eval-when-form) | |
932 | (syntax-case e () | |
933 | ((_ (x ...) e1 e2 ...) | |
934 | (let ((when-list (chi-when-list e #'(x ...) w)) | |
935 | (body #'(e1 e2 ...))) | |
936 | (cond | |
937 | ((eq? m 'e) | |
938 | (if (memq 'eval when-list) | |
939 | (scan body r w s | |
940 | (if (memq 'expand when-list) 'c&e 'e) | |
941 | '(eval) | |
942 | mod exps) | |
943 | (begin | |
944 | (if (memq 'expand when-list) | |
945 | (top-level-eval-hook | |
946 | (chi-top-sequence body r w s 'e '(eval) mod) | |
947 | mod)) | |
948 | (values exps)))) | |
949 | ((memq 'load when-list) | |
950 | (if (or (memq 'compile when-list) | |
951 | (memq 'expand when-list) | |
952 | (and (eq? m 'c&e) (memq 'eval when-list))) | |
953 | (scan body r w s 'c&e '(compile load) mod exps) | |
954 | (if (memq m '(c c&e)) | |
955 | (scan body r w s 'c '(load) mod exps) | |
956 | (values exps)))) | |
957 | ((or (memq 'compile when-list) | |
958 | (memq 'expand when-list) | |
959 | (and (eq? m 'c&e) (memq 'eval when-list))) | |
960 | (top-level-eval-hook | |
961 | (chi-top-sequence body r w s 'e '(eval) mod) | |
962 | mod) | |
963 | (values exps)) | |
964 | (else | |
965 | (values exps))))))) | |
966 | ((define-syntax-form) | |
967 | (let ((n (id-var-name value w)) (r (macros-only-env r))) | |
968 | (case m | |
969 | ((c) | |
970 | (if (memq 'compile esew) | |
971 | (let ((e (chi-install-global n (chi e r w mod)))) | |
972 | (top-level-eval-hook e mod) | |
973 | (if (memq 'load esew) | |
974 | (values (cons e exps)) | |
975 | (values exps))) | |
976 | (if (memq 'load esew) | |
977 | (values (cons (chi-install-global n (chi e r w mod)) | |
978 | exps)) | |
979 | (values exps)))) | |
980 | ((c&e) | |
981 | (let ((e (chi-install-global n (chi e r w mod)))) | |
982 | (top-level-eval-hook e mod) | |
983 | (values (cons e exps)))) | |
984 | (else | |
985 | (if (memq 'eval esew) | |
986 | (top-level-eval-hook | |
987 | (chi-install-global n (chi e r w mod)) | |
988 | mod)) | |
989 | (values exps))))) | |
990 | ((define-form) | |
991 | (let* ((n (id-var-name value w)) | |
992 | ;; Lookup the name in the module of the define form. | |
993 | (type (binding-type (lookup n r mod)))) | |
994 | (case type | |
995 | ((global core macro module-ref) | |
996 | ;; affect compile-time environment (once we have booted) | |
997 | (if (and (memq m '(c c&e)) | |
998 | (not (module-local-variable (current-module) n)) | |
999 | (current-module)) | |
1000 | (let ((old (module-variable (current-module) n))) | |
1001 | ;; use value of the same-named imported variable, if | |
1002 | ;; any | |
1003 | (if (and (variable? old) (variable-bound? old)) | |
1004 | (module-define! (current-module) n (variable-ref old)) | |
1005 | (module-add! (current-module) n (make-undefined-variable))))) | |
1006 | (values | |
1007 | (cons | |
1008 | (eval-if-c&e m | |
1009 | (build-global-definition s n (chi e r w mod)) | |
1010 | mod) | |
1011 | exps))) | |
1012 | ((displaced-lexical) | |
1013 | (syntax-violation #f "identifier out of context" | |
1014 | e (wrap value w mod))) | |
1015 | (else | |
1016 | (syntax-violation #f "cannot define keyword at top level" | |
1017 | e (wrap value w mod)))))) | |
1018 | (else | |
1019 | (values (cons | |
1020 | (eval-if-c&e m (chi-expr type value e r w s mod) mod) | |
1021 | exps))))))) | |
1022 | (lambda (exps) | |
1023 | (scan (cdr body) r w s m esew mod exps)))))) | |
1024 | ||
1025 | (call-with-values (lambda () | |
1026 | (scan body r w s m esew mod '())) | |
1027 | (lambda (exps) | |
1028 | (if (null? exps) | |
1029 | (build-void s) | |
1030 | (build-sequence s (reverse exps))))))) | |
1031 | ||
8fad25c2 AW |
1032 | (define chi-install-global |
1033 | (lambda (name e) | |
1034 | (build-global-definition | |
1035 | no-source | |
1036 | name | |
1037 | (build-application | |
1038 | no-source | |
1039 | (build-primref no-source 'make-syntax-transformer) | |
1040 | (list (build-data no-source name) | |
1041 | (build-data no-source 'macro) | |
1042 | e))))) | |
5f161164 | 1043 | |
8fad25c2 AW |
1044 | (define chi-when-list |
1045 | (lambda (e when-list w) | |
1046 | ;; when-list is syntax'd version of list of situations | |
1047 | (let f ((when-list when-list) (situations '())) | |
1048 | (if (null? when-list) | |
1049 | situations | |
1050 | (f (cdr when-list) | |
1051 | (cons (let ((x (car when-list))) | |
1052 | (cond | |
1053 | ((free-id=? x #'compile) 'compile) | |
1054 | ((free-id=? x #'load) 'load) | |
1055 | ((free-id=? x #'eval) 'eval) | |
1056 | ((free-id=? x #'expand) 'expand) | |
1057 | (else (syntax-violation 'eval-when | |
1058 | "invalid situation" | |
1059 | e (wrap x w #f))))) | |
1060 | situations)))))) | |
1061 | ||
1062 | ;; syntax-type returns six values: type, value, e, w, s, and mod. The | |
1063 | ;; first two are described in the table below. | |
1064 | ;; | |
1065 | ;; type value explanation | |
1066 | ;; ------------------------------------------------------------------- | |
1067 | ;; core procedure core singleton | |
1068 | ;; core-form procedure core form | |
1069 | ;; module-ref procedure @ or @@ singleton | |
1070 | ;; lexical name lexical variable reference | |
1071 | ;; global name global variable reference | |
1072 | ;; begin none begin keyword | |
1073 | ;; define none define keyword | |
1074 | ;; define-syntax none define-syntax keyword | |
1075 | ;; local-syntax rec? letrec-syntax/let-syntax keyword | |
1076 | ;; eval-when none eval-when keyword | |
1077 | ;; syntax level pattern variable | |
1078 | ;; displaced-lexical none displaced lexical identifier | |
1079 | ;; lexical-call name call to lexical variable | |
1080 | ;; global-call name call to global variable | |
1081 | ;; call none any other call | |
1082 | ;; begin-form none begin expression | |
1083 | ;; define-form id variable definition | |
1084 | ;; define-syntax-form id syntax definition | |
1085 | ;; local-syntax-form rec? syntax definition | |
1086 | ;; eval-when-form none eval-when form | |
1087 | ;; constant none self-evaluating datum | |
1088 | ;; other none anything else | |
1089 | ;; | |
1090 | ;; For define-form and define-syntax-form, e is the rhs expression. | |
1091 | ;; For all others, e is the entire form. w is the wrap for e. | |
1092 | ;; s is the source for the entire form. mod is the module for e. | |
1093 | ;; | |
1094 | ;; syntax-type expands macros and unwraps as necessary to get to | |
1095 | ;; one of the forms above. It also parses define and define-syntax | |
1096 | ;; forms, although perhaps this should be done by the consumer. | |
1097 | ||
1098 | (define syntax-type | |
1099 | (lambda (e r w s rib mod for-car?) | |
1100 | (cond | |
1101 | ((symbol? e) | |
1102 | (let* ((n (id-var-name e w)) | |
1103 | (b (lookup n r mod)) | |
1104 | (type (binding-type b))) | |
1105 | (case type | |
1106 | ((lexical) (values type (binding-value b) e w s mod)) | |
1107 | ((global) (values type n e w s mod)) | |
1108 | ((macro) | |
1109 | (if for-car? | |
1110 | (values type (binding-value b) e w s mod) | |
1111 | (syntax-type (chi-macro (binding-value b) e r w s rib mod) | |
1112 | r empty-wrap s rib mod #f))) | |
1113 | (else (values type (binding-value b) e w s mod))))) | |
1114 | ((pair? e) | |
1115 | (let ((first (car e))) | |
1116 | (call-with-values | |
1117 | (lambda () (syntax-type first r w s rib mod #t)) | |
1118 | (lambda (ftype fval fe fw fs fmod) | |
1119 | (case ftype | |
1120 | ((lexical) | |
1121 | (values 'lexical-call fval e w s mod)) | |
1122 | ((global) | |
1123 | ;; If we got here via an (@@ ...) expansion, we need to | |
1124 | ;; make sure the fmod information is propagated back | |
1125 | ;; correctly -- hence this consing. | |
1126 | (values 'global-call (make-syntax-object fval w fmod) | |
1127 | e w s mod)) | |
1128 | ((macro) | |
1129 | (syntax-type (chi-macro fval e r w s rib mod) | |
1130 | r empty-wrap s rib mod for-car?)) | |
1131 | ((module-ref) | |
1132 | (call-with-values (lambda () (fval e r w)) | |
1133 | (lambda (e r w s mod) | |
1134 | (syntax-type e r w s rib mod for-car?)))) | |
1135 | ((core) | |
1136 | (values 'core-form fval e w s mod)) | |
1137 | ((local-syntax) | |
1138 | (values 'local-syntax-form fval e w s mod)) | |
1139 | ((begin) | |
1140 | (values 'begin-form #f e w s mod)) | |
1141 | ((eval-when) | |
1142 | (values 'eval-when-form #f e w s mod)) | |
1143 | ((define) | |
1144 | (syntax-case e () | |
1145 | ((_ name val) | |
1146 | (id? #'name) | |
1147 | (values 'define-form #'name #'val w s mod)) | |
1148 | ((_ (name . args) e1 e2 ...) | |
1149 | (and (id? #'name) | |
1150 | (valid-bound-ids? (lambda-var-list #'args))) | |
1151 | ;; need lambda here... | |
1152 | (values 'define-form (wrap #'name w mod) | |
1153 | (decorate-source | |
1154 | (cons #'lambda (wrap #'(args e1 e2 ...) w mod)) | |
1155 | s) | |
1156 | empty-wrap s mod)) | |
1157 | ((_ name) | |
1158 | (id? #'name) | |
1159 | (values 'define-form (wrap #'name w mod) | |
1160 | #'(if #f #f) | |
1161 | empty-wrap s mod)))) | |
1162 | ((define-syntax) | |
1163 | (syntax-case e () | |
1164 | ((_ name val) | |
1165 | (id? #'name) | |
1166 | (values 'define-syntax-form #'name | |
1167 | #'val w s mod)))) | |
1168 | (else | |
1169 | (values 'call #f e w s mod))))))) | |
1170 | ((syntax-object? e) | |
1171 | (syntax-type (syntax-object-expression e) | |
1172 | r | |
1173 | (join-wraps w (syntax-object-wrap e)) | |
1174 | (or (source-annotation e) s) rib | |
1175 | (or (syntax-object-module e) mod) for-car?)) | |
1176 | ((self-evaluating? e) (values 'constant #f e w s mod)) | |
1177 | (else (values 'other #f e w s mod))))) | |
1178 | ||
8fad25c2 AW |
1179 | (define chi |
1180 | (lambda (e r w mod) | |
1181 | (call-with-values | |
1182 | (lambda () (syntax-type e r w (source-annotation e) #f mod #f)) | |
1183 | (lambda (type value e w s mod) | |
1184 | (chi-expr type value e r w s mod))))) | |
1185 | ||
1186 | (define chi-expr | |
1187 | (lambda (type value e r w s mod) | |
1188 | (case type | |
1189 | ((lexical) | |
1190 | (build-lexical-reference 'value s e value)) | |
1191 | ((core core-form) | |
1192 | ;; apply transformer | |
1193 | (value e r w s mod)) | |
1194 | ((module-ref) | |
1195 | (call-with-values (lambda () (value e r w)) | |
1196 | (lambda (e r w s mod) | |
1197 | (chi e r w mod)))) | |
1198 | ((lexical-call) | |
1199 | (chi-application | |
1200 | (let ((id (car e))) | |
1201 | (build-lexical-reference 'fun (source-annotation id) | |
1202 | (if (syntax-object? id) | |
1203 | (syntax->datum id) | |
1204 | id) | |
1205 | value)) | |
1206 | e r w s mod)) | |
1207 | ((global-call) | |
1208 | (chi-application | |
1209 | (build-global-reference (source-annotation (car e)) | |
1210 | (if (syntax-object? value) | |
1211 | (syntax-object-expression value) | |
1212 | value) | |
1213 | (if (syntax-object? value) | |
1214 | (syntax-object-module value) | |
1215 | mod)) | |
1216 | e r w s mod)) | |
1217 | ((constant) (build-data s (strip (source-wrap e w s mod) empty-wrap))) | |
1218 | ((global) (build-global-reference s value mod)) | |
1219 | ((call) (chi-application (chi (car e) r w mod) e r w s mod)) | |
1220 | ((begin-form) | |
1221 | (syntax-case e () | |
1222 | ((_ e1 e2 ...) (chi-sequence #'(e1 e2 ...) r w s mod)))) | |
1223 | ((local-syntax-form) | |
1224 | (chi-local-syntax value e r w s mod chi-sequence)) | |
1225 | ((eval-when-form) | |
1226 | (syntax-case e () | |
1227 | ((_ (x ...) e1 e2 ...) | |
1228 | (let ((when-list (chi-when-list e #'(x ...) w))) | |
1229 | (if (memq 'eval when-list) | |
1230 | (chi-sequence #'(e1 e2 ...) r w s mod) | |
1231 | (chi-void)))))) | |
1232 | ((define-form define-syntax-form) | |
1233 | (syntax-violation #f "definition in expression context" | |
1234 | e (wrap value w mod))) | |
1235 | ((syntax) | |
1236 | (syntax-violation #f "reference to pattern variable outside syntax form" | |
1237 | (source-wrap e w s mod))) | |
1238 | ((displaced-lexical) | |
1239 | (syntax-violation #f "reference to identifier outside its scope" | |
1240 | (source-wrap e w s mod))) | |
1241 | (else (syntax-violation #f "unexpected syntax" | |
1242 | (source-wrap e w s mod)))))) | |
1243 | ||
1244 | (define chi-application | |
1245 | (lambda (x e r w s mod) | |
1246 | (syntax-case e () | |
1247 | ((e0 e1 ...) | |
1248 | (build-application s x | |
1249 | (map (lambda (e) (chi e r w mod)) #'(e1 ...))))))) | |
1250 | ||
1251 | ;; (What follows is my interpretation of what's going on here -- Andy) | |
1252 | ;; | |
1253 | ;; A macro takes an expression, a tree, the leaves of which are identifiers | |
1254 | ;; and datums. Identifiers are symbols along with a wrap and a module. For | |
1255 | ;; efficiency, subtrees that share wraps and modules may be grouped as one | |
1256 | ;; syntax object. | |
c3ae0ed4 | 1257 | ;; |
8fad25c2 AW |
1258 | ;; Going into the expansion, the expression is given an anti-mark, which |
1259 | ;; logically propagates to all leaves. Then, in the new expression returned | |
1260 | ;; from the transfomer, if we see an expression with an anti-mark, we know it | |
1261 | ;; pertains to the original expression; conversely, expressions without the | |
1262 | ;; anti-mark are known to be introduced by the transformer. | |
c3ae0ed4 | 1263 | ;; |
8fad25c2 AW |
1264 | ;; OK, good until now. We know this algorithm does lexical scoping |
1265 | ;; appropriately because it's widely known in the literature, and psyntax is | |
1266 | ;; widely used. But what about modules? Here we're on our own. What we do is | |
1267 | ;; to mark the module of expressions produced by a macro as pertaining to the | |
1268 | ;; module that was current when the macro was defined -- that is, free | |
1269 | ;; identifiers introduced by a macro are scoped in the macro's module, not in | |
1270 | ;; the expansion's module. Seems to work well. | |
c3ae0ed4 | 1271 | ;; |
8fad25c2 AW |
1272 | ;; The only wrinkle is when we want a macro to expand to code in another |
1273 | ;; module, as is the case for the r6rs `library' form -- the body expressions | |
1274 | ;; should be scoped relative the the new module, the one defined by the macro. | |
1275 | ;; For that, use `(@@ mod-name body)'. | |
c3ae0ed4 | 1276 | ;; |
8fad25c2 AW |
1277 | ;; Part of the macro output will be from the site of the macro use and part |
1278 | ;; from the macro definition. We allow source information from the macro use | |
1279 | ;; to pass through, but we annotate the parts coming from the macro with the | |
1280 | ;; source location information corresponding to the macro use. It would be | |
1281 | ;; really nice if we could also annotate introduced expressions with the | |
1282 | ;; locations corresponding to the macro definition, but that is not yet | |
1283 | ;; possible. | |
1284 | (define chi-macro | |
1285 | (lambda (p e r w s rib mod) | |
1286 | (define rebuild-macro-output | |
1287 | (lambda (x m) | |
1288 | (cond ((pair? x) | |
1289 | (decorate-source | |
1290 | (cons (rebuild-macro-output (car x) m) | |
1291 | (rebuild-macro-output (cdr x) m)) | |
1292 | s)) | |
1293 | ((syntax-object? x) | |
1294 | (let ((w (syntax-object-wrap x))) | |
1295 | (let ((ms (wrap-marks w)) (s (wrap-subst w))) | |
1296 | (if (and (pair? ms) (eq? (car ms) the-anti-mark)) | |
1297 | ;; output is from original text | |
1298 | (make-syntax-object | |
1299 | (syntax-object-expression x) | |
1300 | (make-wrap (cdr ms) (if rib (cons rib (cdr s)) (cdr s))) | |
1301 | (syntax-object-module x)) | |
1302 | ;; output introduced by macro | |
1303 | (make-syntax-object | |
1304 | (decorate-source (syntax-object-expression x) s) | |
1305 | (make-wrap (cons m ms) | |
1306 | (if rib | |
1307 | (cons rib (cons 'shift s)) | |
1308 | (cons 'shift s))) | |
1309 | (syntax-object-module x)))))) | |
1310 | ||
1311 | ((vector? x) | |
1312 | (let* ((n (vector-length x)) | |
1313 | (v (decorate-source (make-vector n) x))) | |
1314 | (do ((i 0 (fx+ i 1))) | |
1315 | ((fx= i n) v) | |
1316 | (vector-set! v i | |
1317 | (rebuild-macro-output (vector-ref x i) m))))) | |
1318 | ((symbol? x) | |
1319 | (syntax-violation #f "encountered raw symbol in macro output" | |
1320 | (source-wrap e w (wrap-subst w) mod) x)) | |
1321 | (else (decorate-source x s))))) | |
1322 | (rebuild-macro-output (p (source-wrap e (anti-mark w) s mod)) | |
1323 | (new-mark)))) | |
1324 | ||
1325 | (define chi-body | |
1326 | ;; In processing the forms of the body, we create a new, empty wrap. | |
1327 | ;; This wrap is augmented (destructively) each time we discover that | |
1328 | ;; the next form is a definition. This is done: | |
1329 | ;; | |
1330 | ;; (1) to allow the first nondefinition form to be a call to | |
1331 | ;; one of the defined ids even if the id previously denoted a | |
1332 | ;; definition keyword or keyword for a macro expanding into a | |
1333 | ;; definition; | |
1334 | ;; (2) to prevent subsequent definition forms (but unfortunately | |
1335 | ;; not earlier ones) and the first nondefinition form from | |
1336 | ;; confusing one of the bound identifiers for an auxiliary | |
1337 | ;; keyword; and | |
1338 | ;; (3) so that we do not need to restart the expansion of the | |
1339 | ;; first nondefinition form, which is problematic anyway | |
1340 | ;; since it might be the first element of a begin that we | |
1341 | ;; have just spliced into the body (meaning if we restarted, | |
1342 | ;; we'd really need to restart with the begin or the macro | |
1343 | ;; call that expanded into the begin, and we'd have to give | |
1344 | ;; up allowing (begin <defn>+ <expr>+), which is itself | |
1345 | ;; problematic since we don't know if a begin contains only | |
1346 | ;; definitions until we've expanded it). | |
1347 | ;; | |
1348 | ;; Before processing the body, we also create a new environment | |
1349 | ;; containing a placeholder for the bindings we will add later and | |
1350 | ;; associate this environment with each form. In processing a | |
1351 | ;; let-syntax or letrec-syntax, the associated environment may be | |
1352 | ;; augmented with local keyword bindings, so the environment may | |
1353 | ;; be different for different forms in the body. Once we have | |
1354 | ;; gathered up all of the definitions, we evaluate the transformer | |
1355 | ;; expressions and splice into r at the placeholder the new variable | |
1356 | ;; and keyword bindings. This allows let-syntax or letrec-syntax | |
1357 | ;; forms local to a portion or all of the body to shadow the | |
1358 | ;; definition bindings. | |
1359 | ;; | |
1360 | ;; Subforms of a begin, let-syntax, or letrec-syntax are spliced | |
1361 | ;; into the body. | |
1362 | ;; | |
1363 | ;; outer-form is fully wrapped w/source | |
1364 | (lambda (body outer-form r w mod) | |
1365 | (let* ((r (cons '("placeholder" . (placeholder)) r)) | |
1366 | (ribcage (make-empty-ribcage)) | |
1367 | (w (make-wrap (wrap-marks w) (cons ribcage (wrap-subst w))))) | |
1368 | (let parse ((body (map (lambda (x) (cons r (wrap x w mod))) body)) | |
1369 | (ids '()) (labels '()) | |
1370 | (var-ids '()) (vars '()) (vals '()) (bindings '())) | |
1371 | (if (null? body) | |
1372 | (syntax-violation #f "no expressions in body" outer-form) | |
1373 | (let ((e (cdar body)) (er (caar body))) | |
1374 | (call-with-values | |
1375 | (lambda () (syntax-type e er empty-wrap (source-annotation er) ribcage mod #f)) | |
1376 | (lambda (type value e w s mod) | |
1377 | (case type | |
1378 | ((define-form) | |
1379 | (let ((id (wrap value w mod)) (label (gen-label))) | |
1380 | (let ((var (gen-var id))) | |
1381 | (extend-ribcage! ribcage id label) | |
1382 | (parse (cdr body) | |
1383 | (cons id ids) (cons label labels) | |
1384 | (cons id var-ids) | |
1385 | (cons var vars) (cons (cons er (wrap e w mod)) vals) | |
1386 | (cons (make-binding 'lexical var) bindings))))) | |
1387 | ((define-syntax-form) | |
1388 | (let ((id (wrap value w mod)) (label (gen-label))) | |
c3ae0ed4 AW |
1389 | (extend-ribcage! ribcage id label) |
1390 | (parse (cdr body) | |
1391 | (cons id ids) (cons label labels) | |
8fad25c2 AW |
1392 | var-ids vars vals |
1393 | (cons (make-binding 'macro (cons er (wrap e w mod))) | |
1394 | bindings)))) | |
1395 | ((begin-form) | |
1396 | (syntax-case e () | |
1397 | ((_ e1 ...) | |
1398 | (parse (let f ((forms #'(e1 ...))) | |
1399 | (if (null? forms) | |
1400 | (cdr body) | |
1401 | (cons (cons er (wrap (car forms) w mod)) | |
1402 | (f (cdr forms))))) | |
1403 | ids labels var-ids vars vals bindings)))) | |
1404 | ((local-syntax-form) | |
1405 | (chi-local-syntax value e er w s mod | |
1406 | (lambda (forms er w s mod) | |
1407 | (parse (let f ((forms forms)) | |
1408 | (if (null? forms) | |
1409 | (cdr body) | |
1410 | (cons (cons er (wrap (car forms) w mod)) | |
1411 | (f (cdr forms))))) | |
1412 | ids labels var-ids vars vals bindings)))) | |
1413 | (else ; found a non-definition | |
1414 | (if (null? ids) | |
1415 | (build-sequence no-source | |
1416 | (map (lambda (x) | |
1417 | (chi (cdr x) (car x) empty-wrap mod)) | |
1418 | (cons (cons er (source-wrap e w s mod)) | |
1419 | (cdr body)))) | |
1420 | (begin | |
1421 | (if (not (valid-bound-ids? ids)) | |
1422 | (syntax-violation | |
1423 | #f "invalid or duplicate identifier in definition" | |
1424 | outer-form)) | |
1425 | (let loop ((bs bindings) (er-cache #f) (r-cache #f)) | |
1426 | (if (not (null? bs)) | |
1427 | (let* ((b (car bs))) | |
1428 | (if (eq? (car b) 'macro) | |
1429 | (let* ((er (cadr b)) | |
1430 | (r-cache | |
1431 | (if (eq? er er-cache) | |
1432 | r-cache | |
1433 | (macros-only-env er)))) | |
1434 | (set-cdr! b | |
1435 | (eval-local-transformer | |
1436 | (chi (cddr b) r-cache empty-wrap mod) | |
1437 | mod)) | |
1438 | (loop (cdr bs) er r-cache)) | |
1439 | (loop (cdr bs) er-cache r-cache))))) | |
1440 | (set-cdr! r (extend-env labels bindings (cdr r))) | |
1441 | (build-letrec no-source #t | |
1442 | (reverse (map syntax->datum var-ids)) | |
1443 | (reverse vars) | |
1444 | (map (lambda (x) | |
1445 | (chi (cdr x) (car x) empty-wrap mod)) | |
1446 | (reverse vals)) | |
1447 | (build-sequence no-source | |
1448 | (map (lambda (x) | |
1449 | (chi (cdr x) (car x) empty-wrap mod)) | |
1450 | (cons (cons er (source-wrap e w s mod)) | |
1451 | (cdr body))))))))))))))))) | |
1452 | ||
1453 | (define chi-local-syntax | |
1454 | (lambda (rec? e r w s mod k) | |
1455 | (syntax-case e () | |
1456 | ((_ ((id val) ...) e1 e2 ...) | |
1457 | (let ((ids #'(id ...))) | |
1458 | (if (not (valid-bound-ids? ids)) | |
1459 | (syntax-violation #f "duplicate bound keyword" e) | |
1460 | (let ((labels (gen-labels ids))) | |
1461 | (let ((new-w (make-binding-wrap ids labels w))) | |
1462 | (k #'(e1 e2 ...) | |
1463 | (extend-env | |
1464 | labels | |
1465 | (let ((w (if rec? new-w w)) | |
1466 | (trans-r (macros-only-env r))) | |
1467 | (map (lambda (x) | |
1468 | (make-binding 'macro | |
1469 | (eval-local-transformer | |
1470 | (chi x trans-r w mod) | |
1471 | mod))) | |
1472 | #'(val ...))) | |
1473 | r) | |
1474 | new-w | |
1475 | s | |
1476 | mod)))))) | |
1477 | (_ (syntax-violation #f "bad local syntax definition" | |
1478 | (source-wrap e w s mod)))))) | |
1479 | ||
1480 | (define eval-local-transformer | |
1481 | (lambda (expanded mod) | |
1482 | (let ((p (local-eval-hook expanded mod))) | |
1483 | (if (procedure? p) | |
1484 | p | |
1485 | (syntax-violation #f "nonprocedure transformer" p))))) | |
1486 | ||
1487 | (define chi-void | |
1488 | (lambda () | |
1489 | (build-void no-source))) | |
1490 | ||
1491 | (define ellipsis? | |
1492 | (lambda (x) | |
1493 | (and (nonsymbol-id? x) | |
1494 | (free-id=? x #'(... ...))))) | |
1495 | ||
1496 | (define lambda-formals | |
1497 | (lambda (orig-args) | |
1498 | (define (req args rreq) | |
1499 | (syntax-case args () | |
1500 | (() | |
1501 | (check (reverse rreq) #f)) | |
1502 | ((a . b) (id? #'a) | |
1503 | (req #'b (cons #'a rreq))) | |
1504 | (r (id? #'r) | |
1505 | (check (reverse rreq) #'r)) | |
1506 | (else | |
1507 | (syntax-violation 'lambda "invalid argument list" orig-args args)))) | |
1508 | (define (check req rest) | |
1509 | (cond | |
1510 | ((distinct-bound-ids? (if rest (cons rest req) req)) | |
1511 | (values req #f rest #f)) | |
1512 | (else | |
1513 | (syntax-violation 'lambda "duplicate identifier in argument list" | |
1514 | orig-args)))) | |
1515 | (req orig-args '()))) | |
1516 | ||
1517 | (define chi-simple-lambda | |
1518 | (lambda (e r w s mod req rest meta body) | |
1519 | (let* ((ids (if rest (append req (list rest)) req)) | |
1520 | (vars (map gen-var ids)) | |
1521 | (labels (gen-labels ids))) | |
1522 | (build-simple-lambda | |
1523 | s | |
1524 | (map syntax->datum req) (and rest (syntax->datum rest)) vars | |
1525 | meta | |
1526 | (chi-body body (source-wrap e w s mod) | |
1527 | (extend-var-env labels vars r) | |
1528 | (make-binding-wrap ids labels w) | |
1529 | mod))))) | |
1530 | ||
1531 | (define lambda*-formals | |
1532 | (lambda (orig-args) | |
1533 | (define (req args rreq) | |
1534 | (syntax-case args () | |
1535 | (() | |
1536 | (check (reverse rreq) '() #f '())) | |
1537 | ((a . b) (id? #'a) | |
1538 | (req #'b (cons #'a rreq))) | |
1539 | ((a . b) (eq? (syntax->datum #'a) #:optional) | |
1540 | (opt #'b (reverse rreq) '())) | |
1541 | ((a . b) (eq? (syntax->datum #'a) #:key) | |
1542 | (key #'b (reverse rreq) '() '())) | |
1543 | ((a b) (eq? (syntax->datum #'a) #:rest) | |
1544 | (rest #'b (reverse rreq) '() '())) | |
1545 | (r (id? #'r) | |
1546 | (rest #'r (reverse rreq) '() '())) | |
1547 | (else | |
1548 | (syntax-violation 'lambda* "invalid argument list" orig-args args)))) | |
1549 | (define (opt args req ropt) | |
1550 | (syntax-case args () | |
1551 | (() | |
1552 | (check req (reverse ropt) #f '())) | |
1553 | ((a . b) (id? #'a) | |
1554 | (opt #'b req (cons #'(a #f) ropt))) | |
1555 | (((a init) . b) (id? #'a) | |
1556 | (opt #'b req (cons #'(a init) ropt))) | |
1557 | ((a . b) (eq? (syntax->datum #'a) #:key) | |
1558 | (key #'b req (reverse ropt) '())) | |
1559 | ((a b) (eq? (syntax->datum #'a) #:rest) | |
1560 | (rest #'b req (reverse ropt) '())) | |
1561 | (r (id? #'r) | |
1562 | (rest #'r req (reverse ropt) '())) | |
1563 | (else | |
1564 | (syntax-violation 'lambda* "invalid optional argument list" | |
1565 | orig-args args)))) | |
1566 | (define (key args req opt rkey) | |
1567 | (syntax-case args () | |
1568 | (() | |
1569 | (check req opt #f (cons #f (reverse rkey)))) | |
1570 | ((a . b) (id? #'a) | |
1571 | (with-syntax ((k (symbol->keyword (syntax->datum #'a)))) | |
1572 | (key #'b req opt (cons #'(k a #f) rkey)))) | |
1573 | (((a init) . b) (id? #'a) | |
1574 | (with-syntax ((k (symbol->keyword (syntax->datum #'a)))) | |
1575 | (key #'b req opt (cons #'(k a init) rkey)))) | |
1576 | (((a init k) . b) (and (id? #'a) | |
1577 | (keyword? (syntax->datum #'k))) | |
1578 | (key #'b req opt (cons #'(k a init) rkey))) | |
1579 | ((aok) (eq? (syntax->datum #'aok) #:allow-other-keys) | |
1580 | (check req opt #f (cons #t (reverse rkey)))) | |
1581 | ((aok a b) (and (eq? (syntax->datum #'aok) #:allow-other-keys) | |
1582 | (eq? (syntax->datum #'a) #:rest)) | |
1583 | (rest #'b req opt (cons #t (reverse rkey)))) | |
1584 | ((aok . r) (and (eq? (syntax->datum #'aok) #:allow-other-keys) | |
1585 | (id? #'r)) | |
1586 | (rest #'r req opt (cons #t (reverse rkey)))) | |
1587 | ((a b) (eq? (syntax->datum #'a) #:rest) | |
1588 | (rest #'b req opt (cons #f (reverse rkey)))) | |
1589 | (r (id? #'r) | |
1590 | (rest #'r req opt (cons #f (reverse rkey)))) | |
1591 | (else | |
1592 | (syntax-violation 'lambda* "invalid keyword argument list" | |
1593 | orig-args args)))) | |
1594 | (define (rest args req opt kw) | |
1595 | (syntax-case args () | |
1596 | (r (id? #'r) | |
1597 | (check req opt #'r kw)) | |
1598 | (else | |
1599 | (syntax-violation 'lambda* "invalid rest argument" | |
1600 | orig-args args)))) | |
1601 | (define (check req opt rest kw) | |
1602 | (cond | |
1603 | ((distinct-bound-ids? | |
1604 | (append req (map car opt) (if rest (list rest) '()) | |
1605 | (if (pair? kw) (map cadr (cdr kw)) '()))) | |
1606 | (values req opt rest kw)) | |
1607 | (else | |
1608 | (syntax-violation 'lambda* "duplicate identifier in argument list" | |
1609 | orig-args)))) | |
1610 | (req orig-args '()))) | |
1611 | ||
1612 | (define chi-lambda-case | |
1613 | (lambda (e r w s mod get-formals clauses) | |
1614 | (define (expand-req req opt rest kw body) | |
1615 | (let ((vars (map gen-var req)) | |
1616 | (labels (gen-labels req))) | |
1617 | (let ((r* (extend-var-env labels vars r)) | |
1618 | (w* (make-binding-wrap req labels w))) | |
1619 | (expand-opt (map syntax->datum req) | |
1620 | opt rest kw body (reverse vars) r* w* '() '())))) | |
1621 | (define (expand-opt req opt rest kw body vars r* w* out inits) | |
1622 | (cond | |
1623 | ((pair? opt) | |
1624 | (syntax-case (car opt) () | |
1625 | ((id i) | |
1626 | (let* ((v (gen-var #'id)) | |
1627 | (l (gen-labels (list v))) | |
1628 | (r** (extend-var-env l (list v) r*)) | |
1629 | (w** (make-binding-wrap (list #'id) l w*))) | |
1630 | (expand-opt req (cdr opt) rest kw body (cons v vars) | |
1631 | r** w** (cons (syntax->datum #'id) out) | |
1632 | (cons (chi #'i r* w* mod) inits)))))) | |
1633 | (rest | |
1634 | (let* ((v (gen-var rest)) | |
1635 | (l (gen-labels (list v))) | |
1636 | (r* (extend-var-env l (list v) r*)) | |
1637 | (w* (make-binding-wrap (list rest) l w*))) | |
1638 | (expand-kw req (if (pair? out) (reverse out) #f) | |
1639 | (syntax->datum rest) | |
1640 | (if (pair? kw) (cdr kw) kw) | |
1641 | body (cons v vars) r* w* | |
1642 | (if (pair? kw) (car kw) #f) | |
1643 | '() inits))) | |
1644 | (else | |
1645 | (expand-kw req (if (pair? out) (reverse out) #f) #f | |
c3ae0ed4 | 1646 | (if (pair? kw) (cdr kw) kw) |
8fad25c2 | 1647 | body vars r* w* |
c3ae0ed4 | 1648 | (if (pair? kw) (car kw) #f) |
8fad25c2 AW |
1649 | '() inits)))) |
1650 | (define (expand-kw req opt rest kw body vars r* w* aok out inits) | |
1651 | (cond | |
1652 | ((pair? kw) | |
1653 | (syntax-case (car kw) () | |
1654 | ((k id i) | |
1655 | (let* ((v (gen-var #'id)) | |
1656 | (l (gen-labels (list v))) | |
1657 | (r** (extend-var-env l (list v) r*)) | |
1658 | (w** (make-binding-wrap (list #'id) l w*))) | |
1659 | (expand-kw req opt rest (cdr kw) body (cons v vars) | |
1660 | r** w** aok | |
1661 | (cons (list (syntax->datum #'k) | |
1662 | (syntax->datum #'id) | |
1663 | v) | |
1664 | out) | |
1665 | (cons (chi #'i r* w* mod) inits)))))) | |
1666 | (else | |
1667 | (expand-body req opt rest | |
1668 | (if (or aok (pair? out)) (cons aok (reverse out)) #f) | |
1669 | body (reverse vars) r* w* (reverse inits) '())))) | |
1670 | (define (expand-body req opt rest kw body vars r* w* inits meta) | |
1671 | (syntax-case body () | |
1672 | ((docstring e1 e2 ...) (string? (syntax->datum #'docstring)) | |
1673 | (expand-body req opt rest kw #'(e1 e2 ...) vars r* w* inits | |
1674 | (append meta | |
1675 | `((documentation | |
1676 | . ,(syntax->datum #'docstring)))))) | |
1677 | ((#((k . v) ...) e1 e2 ...) | |
1678 | (expand-body req opt rest kw #'(e1 e2 ...) vars r* w* inits | |
1679 | (append meta (syntax->datum #'((k . v) ...))))) | |
1680 | ((e1 e2 ...) | |
1681 | (values meta req opt rest kw inits vars | |
1682 | (chi-body #'(e1 e2 ...) (source-wrap e w s mod) | |
1683 | r* w* mod))))) | |
1684 | ||
1685 | (syntax-case clauses () | |
1686 | (() (values '() #f)) | |
1687 | (((args e1 e2 ...) (args* e1* e2* ...) ...) | |
1688 | (call-with-values (lambda () (get-formals #'args)) | |
1689 | (lambda (req opt rest kw) | |
1690 | (call-with-values (lambda () | |
1691 | (expand-req req opt rest kw #'(e1 e2 ...))) | |
1692 | (lambda (meta req opt rest kw inits vars body) | |
1693 | (call-with-values | |
1694 | (lambda () | |
1695 | (chi-lambda-case e r w s mod get-formals | |
1696 | #'((args* e1* e2* ...) ...))) | |
1697 | (lambda (meta* else*) | |
1698 | (values | |
1699 | (append meta meta*) | |
1700 | (build-lambda-case s req opt rest kw inits vars | |
1701 | body else*)))))))))))) | |
1702 | ||
1703 | ;; data | |
1704 | ||
1705 | ;; strips syntax-objects down to top-wrap | |
1706 | ;; | |
1707 | ;; since only the head of a list is annotated by the reader, not each pair | |
1708 | ;; in the spine, we also check for pairs whose cars are annotated in case | |
1709 | ;; we've been passed the cdr of an annotated list | |
1710 | ||
1711 | (define strip | |
1712 | (lambda (x w) | |
1713 | (if (top-marked? w) | |
1714 | x | |
1715 | (let f ((x x)) | |
1716 | (cond | |
1717 | ((syntax-object? x) | |
1718 | (strip (syntax-object-expression x) (syntax-object-wrap x))) | |
1719 | ((pair? x) | |
1720 | (let ((a (f (car x))) (d (f (cdr x)))) | |
1721 | (if (and (eq? a (car x)) (eq? d (cdr x))) | |
1722 | x | |
1723 | (cons a d)))) | |
1724 | ((vector? x) | |
1725 | (let ((old (vector->list x))) | |
1726 | (let ((new (map f old))) | |
1727 | (if (and-map* eq? old new) x (list->vector new))))) | |
1728 | (else x)))))) | |
1729 | ||
1730 | ;; lexical variables | |
1731 | ||
1732 | (define gen-var | |
1733 | (lambda (id) | |
1734 | (let ((id (if (syntax-object? id) (syntax-object-expression id) id))) | |
1735 | (build-lexical-var no-source id)))) | |
1736 | ||
1737 | ;; appears to return a reversed list | |
1738 | (define lambda-var-list | |
1739 | (lambda (vars) | |
1740 | (let lvl ((vars vars) (ls '()) (w empty-wrap)) | |
1741 | (cond | |
1742 | ((pair? vars) (lvl (cdr vars) (cons (wrap (car vars) w #f) ls) w)) | |
1743 | ((id? vars) (cons (wrap vars w #f) ls)) | |
1744 | ((null? vars) ls) | |
1745 | ((syntax-object? vars) | |
1746 | (lvl (syntax-object-expression vars) | |
1747 | ls | |
1748 | (join-wraps w (syntax-object-wrap vars)))) | |
1749 | ;; include anything else to be caught by subsequent error | |
1750 | ;; checking | |
1751 | (else (cons vars ls)))))) | |
1752 | ||
1753 | ;; core transformers | |
1754 | ||
1755 | (global-extend 'local-syntax 'letrec-syntax #t) | |
1756 | (global-extend 'local-syntax 'let-syntax #f) | |
1757 | ||
1758 | (global-extend 'core 'fluid-let-syntax | |
1759 | (lambda (e r w s mod) | |
1760 | (syntax-case e () | |
1761 | ((_ ((var val) ...) e1 e2 ...) | |
1762 | (valid-bound-ids? #'(var ...)) | |
1763 | (let ((names (map (lambda (x) (id-var-name x w)) #'(var ...)))) | |
1764 | (for-each | |
1765 | (lambda (id n) | |
1766 | (case (binding-type (lookup n r mod)) | |
1767 | ((displaced-lexical) | |
1768 | (syntax-violation 'fluid-let-syntax | |
1769 | "identifier out of context" | |
1770 | e | |
1771 | (source-wrap id w s mod))))) | |
1772 | #'(var ...) | |
1773 | names) | |
1774 | (chi-body | |
1775 | #'(e1 e2 ...) | |
1776 | (source-wrap e w s mod) | |
1777 | (extend-env | |
1778 | names | |
1779 | (let ((trans-r (macros-only-env r))) | |
1780 | (map (lambda (x) | |
1781 | (make-binding 'macro | |
1782 | (eval-local-transformer (chi x trans-r w mod) | |
1783 | mod))) | |
1784 | #'(val ...))) | |
1785 | r) | |
1786 | w | |
1787 | mod))) | |
1788 | (_ (syntax-violation 'fluid-let-syntax "bad syntax" | |
1789 | (source-wrap e w s mod)))))) | |
1790 | ||
1791 | (global-extend 'core 'quote | |
1792 | (lambda (e r w s mod) | |
1793 | (syntax-case e () | |
1794 | ((_ e) (build-data s (strip #'e w))) | |
1795 | (_ (syntax-violation 'quote "bad syntax" | |
1796 | (source-wrap e w s mod)))))) | |
1797 | ||
1798 | (global-extend 'core 'syntax | |
1799 | (let () | |
1800 | (define gen-syntax | |
1801 | (lambda (src e r maps ellipsis? mod) | |
1802 | (if (id? e) | |
1803 | (let ((label (id-var-name e empty-wrap))) | |
1804 | ;; Mod does not matter, we are looking to see if | |
1805 | ;; the id is lexical syntax. | |
1806 | (let ((b (lookup label r mod))) | |
1807 | (if (eq? (binding-type b) 'syntax) | |
1808 | (call-with-values | |
1809 | (lambda () | |
1810 | (let ((var.lev (binding-value b))) | |
1811 | (gen-ref src (car var.lev) (cdr var.lev) maps))) | |
1812 | (lambda (var maps) (values `(ref ,var) maps))) | |
1813 | (if (ellipsis? e) | |
1814 | (syntax-violation 'syntax "misplaced ellipsis" src) | |
1815 | (values `(quote ,e) maps))))) | |
1816 | (syntax-case e () | |
1817 | ((dots e) | |
1818 | (ellipsis? #'dots) | |
1819 | (gen-syntax src #'e r maps (lambda (x) #f) mod)) | |
1820 | ((x dots . y) | |
1821 | ;; this could be about a dozen lines of code, except that we | |
1822 | ;; choose to handle #'(x ... ...) forms | |
1823 | (ellipsis? #'dots) | |
1824 | (let f ((y #'y) | |
1825 | (k (lambda (maps) | |
1826 | (call-with-values | |
1827 | (lambda () | |
1828 | (gen-syntax src #'x r | |
1829 | (cons '() maps) ellipsis? mod)) | |
1830 | (lambda (x maps) | |
1831 | (if (null? (car maps)) | |
1832 | (syntax-violation 'syntax "extra ellipsis" | |
1833 | src) | |
1834 | (values (gen-map x (car maps)) | |
1835 | (cdr maps)))))))) | |
1836 | (syntax-case y () | |
1837 | ((dots . y) | |
1838 | (ellipsis? #'dots) | |
1839 | (f #'y | |
1840 | (lambda (maps) | |
1841 | (call-with-values | |
1842 | (lambda () (k (cons '() maps))) | |
1843 | (lambda (x maps) | |
1844 | (if (null? (car maps)) | |
1845 | (syntax-violation 'syntax "extra ellipsis" src) | |
1846 | (values (gen-mappend x (car maps)) | |
1847 | (cdr maps)))))))) | |
1848 | (_ (call-with-values | |
1849 | (lambda () (gen-syntax src y r maps ellipsis? mod)) | |
1850 | (lambda (y maps) | |
c3ae0ed4 | 1851 | (call-with-values |
8fad25c2 | 1852 | (lambda () (k maps)) |
c3ae0ed4 | 1853 | (lambda (x maps) |
8fad25c2 AW |
1854 | (values (gen-append x y) maps))))))))) |
1855 | ((x . y) | |
1856 | (call-with-values | |
1857 | (lambda () (gen-syntax src #'x r maps ellipsis? mod)) | |
1858 | (lambda (x maps) | |
1859 | (call-with-values | |
1860 | (lambda () (gen-syntax src #'y r maps ellipsis? mod)) | |
1861 | (lambda (y maps) (values (gen-cons x y) maps)))))) | |
1862 | (#(e1 e2 ...) | |
1863 | (call-with-values | |
1864 | (lambda () | |
1865 | (gen-syntax src #'(e1 e2 ...) r maps ellipsis? mod)) | |
1866 | (lambda (e maps) (values (gen-vector e) maps)))) | |
1867 | (_ (values `(quote ,e) maps)))))) | |
1868 | ||
1869 | (define gen-ref | |
1870 | (lambda (src var level maps) | |
1871 | (if (fx= level 0) | |
1872 | (values var maps) | |
1873 | (if (null? maps) | |
1874 | (syntax-violation 'syntax "missing ellipsis" src) | |
1875 | (call-with-values | |
1876 | (lambda () (gen-ref src var (fx- level 1) (cdr maps))) | |
1877 | (lambda (outer-var outer-maps) | |
1878 | (let ((b (assq outer-var (car maps)))) | |
1879 | (if b | |
1880 | (values (cdr b) maps) | |
1881 | (let ((inner-var (gen-var 'tmp))) | |
1882 | (values inner-var | |
1883 | (cons (cons (cons outer-var inner-var) | |
1884 | (car maps)) | |
1885 | outer-maps))))))))))) | |
1886 | ||
1887 | (define gen-mappend | |
1888 | (lambda (e map-env) | |
1889 | `(apply (primitive append) ,(gen-map e map-env)))) | |
1890 | ||
1891 | (define gen-map | |
1892 | (lambda (e map-env) | |
1893 | (let ((formals (map cdr map-env)) | |
1894 | (actuals (map (lambda (x) `(ref ,(car x))) map-env))) | |
1895 | (cond | |
1896 | ((eq? (car e) 'ref) | |
1897 | ;; identity map equivalence: | |
1898 | ;; (map (lambda (x) x) y) == y | |
1899 | (car actuals)) | |
1900 | ((and-map | |
1901 | (lambda (x) (and (eq? (car x) 'ref) (memq (cadr x) formals))) | |
1902 | (cdr e)) | |
1903 | ;; eta map equivalence: | |
1904 | ;; (map (lambda (x ...) (f x ...)) y ...) == (map f y ...) | |
1905 | `(map (primitive ,(car e)) | |
1906 | ,@(map (let ((r (map cons formals actuals))) | |
1907 | (lambda (x) (cdr (assq (cadr x) r)))) | |
1908 | (cdr e)))) | |
1909 | (else `(map (lambda ,formals ,e) ,@actuals)))))) | |
1910 | ||
1911 | (define gen-cons | |
1912 | (lambda (x y) | |
1913 | (case (car y) | |
1914 | ((quote) | |
1915 | (if (eq? (car x) 'quote) | |
1916 | `(quote (,(cadr x) . ,(cadr y))) | |
1917 | (if (eq? (cadr y) '()) | |
1918 | `(list ,x) | |
1919 | `(cons ,x ,y)))) | |
1920 | ((list) `(list ,x ,@(cdr y))) | |
1921 | (else `(cons ,x ,y))))) | |
1922 | ||
1923 | (define gen-append | |
1924 | (lambda (x y) | |
1925 | (if (equal? y '(quote ())) | |
1926 | x | |
1927 | `(append ,x ,y)))) | |
1928 | ||
1929 | (define gen-vector | |
1930 | (lambda (x) | |
c3ae0ed4 | 1931 | (cond |
8fad25c2 AW |
1932 | ((eq? (car x) 'list) `(vector ,@(cdr x))) |
1933 | ((eq? (car x) 'quote) `(quote #(,@(cadr x)))) | |
1934 | (else `(list->vector ,x))))) | |
1935 | ||
1936 | ||
1937 | (define regen | |
1938 | (lambda (x) | |
1939 | (case (car x) | |
1940 | ((ref) (build-lexical-reference 'value no-source (cadr x) (cadr x))) | |
1941 | ((primitive) (build-primref no-source (cadr x))) | |
1942 | ((quote) (build-data no-source (cadr x))) | |
1943 | ((lambda) | |
1944 | (if (list? (cadr x)) | |
1945 | (build-simple-lambda no-source (cadr x) #f (cadr x) '() (regen (caddr x))) | |
1946 | (error "how did we get here" x))) | |
1947 | (else (build-application no-source | |
1948 | (build-primref no-source (car x)) | |
1949 | (map regen (cdr x))))))) | |
1950 | ||
1951 | (lambda (e r w s mod) | |
1952 | (let ((e (source-wrap e w s mod))) | |
1953 | (syntax-case e () | |
1954 | ((_ x) | |
1955 | (call-with-values | |
1956 | (lambda () (gen-syntax e #'x r '() ellipsis? mod)) | |
1957 | (lambda (e maps) (regen e)))) | |
1958 | (_ (syntax-violation 'syntax "bad `syntax' form" e))))))) | |
1959 | ||
1960 | (global-extend 'core 'lambda | |
c3ae0ed4 | 1961 | (lambda (e r w s mod) |
8fad25c2 AW |
1962 | (syntax-case e () |
1963 | ((_ args e1 e2 ...) | |
1964 | (call-with-values (lambda () (lambda-formals #'args)) | |
1965 | (lambda (req opt rest kw) | |
1966 | (let lp ((body #'(e1 e2 ...)) (meta '())) | |
1967 | (syntax-case body () | |
1968 | ((docstring e1 e2 ...) (string? (syntax->datum #'docstring)) | |
1969 | (lp #'(e1 e2 ...) | |
1970 | (append meta | |
1971 | `((documentation | |
1972 | . ,(syntax->datum #'docstring)))))) | |
1973 | ((#((k . v) ...) e1 e2 ...) | |
1974 | (lp #'(e1 e2 ...) | |
1975 | (append meta (syntax->datum #'((k . v) ...))))) | |
1976 | (_ (chi-simple-lambda e r w s mod req rest meta body))))))) | |
1977 | (_ (syntax-violation 'lambda "bad lambda" e))))) | |
3785c5b2 | 1978 | |
8fad25c2 AW |
1979 | (global-extend 'core 'lambda* |
1980 | (lambda (e r w s mod) | |
1981 | (syntax-case e () | |
1982 | ((_ args e1 e2 ...) | |
1983 | (call-with-values | |
1984 | (lambda () | |
1985 | (chi-lambda-case e r w s mod | |
1986 | lambda*-formals #'((args e1 e2 ...)))) | |
1987 | (lambda (meta lcase) | |
1988 | (build-case-lambda s meta lcase)))) | |
1989 | (_ (syntax-violation 'lambda "bad lambda*" e))))) | |
1990 | ||
1991 | (global-extend 'core 'case-lambda | |
1992 | (lambda (e r w s mod) | |
1993 | (syntax-case e () | |
1994 | ((_ (args e1 e2 ...) (args* e1* e2* ...) ...) | |
1995 | (call-with-values | |
1996 | (lambda () | |
1997 | (chi-lambda-case e r w s mod | |
1998 | lambda-formals | |
1999 | #'((args e1 e2 ...) (args* e1* e2* ...) ...))) | |
2000 | (lambda (meta lcase) | |
2001 | (build-case-lambda s meta lcase)))) | |
2002 | (_ (syntax-violation 'case-lambda "bad case-lambda" e))))) | |
2003 | ||
2004 | (global-extend 'core 'case-lambda* | |
2005 | (lambda (e r w s mod) | |
2006 | (syntax-case e () | |
2007 | ((_ (args e1 e2 ...) (args* e1* e2* ...) ...) | |
2008 | (call-with-values | |
2009 | (lambda () | |
2010 | (chi-lambda-case e r w s mod | |
2011 | lambda*-formals | |
2012 | #'((args e1 e2 ...) (args* e1* e2* ...) ...))) | |
2013 | (lambda (meta lcase) | |
2014 | (build-case-lambda s meta lcase)))) | |
2015 | (_ (syntax-violation 'case-lambda "bad case-lambda*" e))))) | |
2016 | ||
2017 | (global-extend 'core 'let | |
2018 | (let () | |
2019 | (define (chi-let e r w s mod constructor ids vals exps) | |
2020 | (if (not (valid-bound-ids? ids)) | |
2021 | (syntax-violation 'let "duplicate bound variable" e) | |
2022 | (let ((labels (gen-labels ids)) | |
2023 | (new-vars (map gen-var ids))) | |
2024 | (let ((nw (make-binding-wrap ids labels w)) | |
2025 | (nr (extend-var-env labels new-vars r))) | |
2026 | (constructor s | |
2027 | (map syntax->datum ids) | |
2028 | new-vars | |
2029 | (map (lambda (x) (chi x r w mod)) vals) | |
2030 | (chi-body exps (source-wrap e nw s mod) | |
2031 | nr nw mod)))))) | |
2032 | (lambda (e r w s mod) | |
2033 | (syntax-case e () | |
2034 | ((_ ((id val) ...) e1 e2 ...) | |
2035 | (and-map id? #'(id ...)) | |
2036 | (chi-let e r w s mod | |
2037 | build-let | |
2038 | #'(id ...) | |
2039 | #'(val ...) | |
2040 | #'(e1 e2 ...))) | |
2041 | ((_ f ((id val) ...) e1 e2 ...) | |
2042 | (and (id? #'f) (and-map id? #'(id ...))) | |
2043 | (chi-let e r w s mod | |
2044 | build-named-let | |
2045 | #'(f id ...) | |
2046 | #'(val ...) | |
2047 | #'(e1 e2 ...))) | |
2048 | (_ (syntax-violation 'let "bad let" (source-wrap e w s mod))))))) | |
2049 | ||
2050 | ||
2051 | (global-extend 'core 'letrec | |
c3ae0ed4 AW |
2052 | (lambda (e r w s mod) |
2053 | (syntax-case e () | |
2054 | ((_ ((id val) ...) e1 e2 ...) | |
2055 | (and-map id? #'(id ...)) | |
8fad25c2 AW |
2056 | (let ((ids #'(id ...))) |
2057 | (if (not (valid-bound-ids? ids)) | |
2058 | (syntax-violation 'letrec "duplicate bound variable" e) | |
2059 | (let ((labels (gen-labels ids)) | |
2060 | (new-vars (map gen-var ids))) | |
2061 | (let ((w (make-binding-wrap ids labels w)) | |
2062 | (r (extend-var-env labels new-vars r))) | |
2063 | (build-letrec s #f | |
2064 | (map syntax->datum ids) | |
2065 | new-vars | |
2066 | (map (lambda (x) (chi x r w mod)) #'(val ...)) | |
2067 | (chi-body #'(e1 e2 ...) | |
2068 | (source-wrap e w s mod) r w mod))))))) | |
2069 | (_ (syntax-violation 'letrec "bad letrec" (source-wrap e w s mod)))))) | |
2070 | ||
2071 | ||
2072 | (global-extend 'core 'letrec* | |
2073 | (lambda (e r w s mod) | |
2074 | (syntax-case e () | |
2075 | ((_ ((id val) ...) e1 e2 ...) | |
2076 | (and-map id? #'(id ...)) | |
2077 | (let ((ids #'(id ...))) | |
2078 | (if (not (valid-bound-ids? ids)) | |
2079 | (syntax-violation 'letrec* "duplicate bound variable" e) | |
2080 | (let ((labels (gen-labels ids)) | |
2081 | (new-vars (map gen-var ids))) | |
2082 | (let ((w (make-binding-wrap ids labels w)) | |
2083 | (r (extend-var-env labels new-vars r))) | |
2084 | (build-letrec s #t | |
2085 | (map syntax->datum ids) | |
2086 | new-vars | |
2087 | (map (lambda (x) (chi x r w mod)) #'(val ...)) | |
2088 | (chi-body #'(e1 e2 ...) | |
2089 | (source-wrap e w s mod) r w mod))))))) | |
2090 | (_ (syntax-violation 'letrec* "bad letrec*" (source-wrap e w s mod)))))) | |
2091 | ||
2092 | ||
2093 | (global-extend 'core 'set! | |
2094 | (lambda (e r w s mod) | |
2095 | (syntax-case e () | |
2096 | ((_ id val) | |
2097 | (id? #'id) | |
2098 | (let ((n (id-var-name #'id w)) | |
2099 | ;; Lookup id in its module | |
2100 | (id-mod (if (syntax-object? #'id) | |
2101 | (syntax-object-module #'id) | |
2102 | mod))) | |
2103 | (let ((b (lookup n r id-mod))) | |
2104 | (case (binding-type b) | |
2105 | ((lexical) | |
2106 | (build-lexical-assignment s | |
2107 | (syntax->datum #'id) | |
2108 | (binding-value b) | |
2109 | (chi #'val r w mod))) | |
2110 | ((global) | |
2111 | (build-global-assignment s n (chi #'val r w mod) id-mod)) | |
2112 | ((macro) | |
2113 | (let ((p (binding-value b))) | |
2114 | (if (procedure-property p 'variable-transformer) | |
2115 | ;; As syntax-type does, call chi-macro with | |
2116 | ;; the mod of the expression. Hmm. | |
2117 | (chi (chi-macro p e r w s #f mod) r empty-wrap mod) | |
2118 | (syntax-violation 'set! "not a variable transformer" | |
2119 | (wrap e w mod) | |
2120 | (wrap #'id w id-mod))))) | |
2121 | ((displaced-lexical) | |
2122 | (syntax-violation 'set! "identifier out of context" | |
2123 | (wrap #'id w mod))) | |
2124 | (else (syntax-violation 'set! "bad set!" | |
2125 | (source-wrap e w s mod))))))) | |
2126 | ((_ (head tail ...) val) | |
2127 | (call-with-values | |
2128 | (lambda () (syntax-type #'head r empty-wrap no-source #f mod #t)) | |
2129 | (lambda (type value ee ww ss modmod) | |
2130 | (case type | |
2131 | ((module-ref) | |
2132 | (let ((val (chi #'val r w mod))) | |
2133 | (call-with-values (lambda () (value #'(head tail ...) r w)) | |
2134 | (lambda (e r w s* mod) | |
2135 | (syntax-case e () | |
2136 | (e (id? #'e) | |
2137 | (build-global-assignment s (syntax->datum #'e) | |
2138 | val mod))))))) | |
2139 | (else | |
2140 | (build-application s | |
2141 | (chi #'(setter head) r w mod) | |
2142 | (map (lambda (e) (chi e r w mod)) | |
2143 | #'(tail ... val)))))))) | |
2144 | (_ (syntax-violation 'set! "bad set!" (source-wrap e w s mod)))))) | |
2145 | ||
2146 | (global-extend 'module-ref '@ | |
2147 | (lambda (e r w) | |
2148 | (syntax-case e () | |
2149 | ((_ (mod ...) id) | |
2150 | (and (and-map id? #'(mod ...)) (id? #'id)) | |
2151 | (values (syntax->datum #'id) r w #f | |
2152 | (syntax->datum | |
2153 | #'(public mod ...))))))) | |
2154 | ||
2155 | (global-extend 'module-ref '@@ | |
2156 | (lambda (e r w) | |
2157 | (define remodulate | |
2158 | (lambda (x mod) | |
2159 | (cond ((pair? x) | |
2160 | (cons (remodulate (car x) mod) | |
2161 | (remodulate (cdr x) mod))) | |
2162 | ((syntax-object? x) | |
2163 | (make-syntax-object | |
2164 | (remodulate (syntax-object-expression x) mod) | |
2165 | (syntax-object-wrap x) | |
2166 | ;; hither the remodulation | |
2167 | mod)) | |
2168 | ((vector? x) | |
2169 | (let* ((n (vector-length x)) (v (make-vector n))) | |
2170 | (do ((i 0 (fx+ i 1))) | |
2171 | ((fx= i n) v) | |
2172 | (vector-set! v i (remodulate (vector-ref x i) mod))))) | |
2173 | (else x)))) | |
2174 | (syntax-case e () | |
2175 | ((_ (mod ...) exp) | |
2176 | (and-map id? #'(mod ...)) | |
2177 | (let ((mod (syntax->datum #'(private mod ...)))) | |
2178 | (values (remodulate #'exp mod) | |
2179 | r w (source-annotation #'exp) | |
2180 | mod)))))) | |
9365d8ad | 2181 | |
8fad25c2 AW |
2182 | (global-extend 'core 'if |
2183 | (lambda (e r w s mod) | |
2184 | (syntax-case e () | |
2185 | ((_ test then) | |
2186 | (build-conditional | |
2187 | s | |
2188 | (chi #'test r w mod) | |
2189 | (chi #'then r w mod) | |
2190 | (build-void no-source))) | |
2191 | ((_ test then else) | |
2192 | (build-conditional | |
2193 | s | |
2194 | (chi #'test r w mod) | |
2195 | (chi #'then r w mod) | |
2196 | (chi #'else r w mod)))))) | |
2197 | ||
2198 | (global-extend 'core 'with-fluids | |
2199 | (lambda (e r w s mod) | |
2200 | (syntax-case e () | |
2201 | ((_ ((fluid val) ...) b b* ...) | |
2202 | (build-dynlet | |
2203 | s | |
2204 | (map (lambda (x) (chi x r w mod)) #'(fluid ...)) | |
2205 | (map (lambda (x) (chi x r w mod)) #'(val ...)) | |
2206 | (chi-body #'(b b* ...) | |
2207 | (source-wrap e w s mod) r w mod)))))) | |
6360c1d4 | 2208 | |
8fad25c2 AW |
2209 | (global-extend 'begin 'begin '()) |
2210 | ||
2211 | (global-extend 'define 'define '()) | |
2212 | ||
2213 | (global-extend 'define-syntax 'define-syntax '()) | |
2214 | ||
2215 | (global-extend 'eval-when 'eval-when '()) | |
2216 | ||
2217 | (global-extend 'core 'syntax-case | |
2218 | (let () | |
2219 | (define convert-pattern | |
2220 | ;; accepts pattern & keys | |
2221 | ;; returns $sc-dispatch pattern & ids | |
2222 | (lambda (pattern keys) | |
2223 | (define cvt* | |
2224 | (lambda (p* n ids) | |
2225 | (if (null? p*) | |
2226 | (values '() ids) | |
2227 | (call-with-values | |
2228 | (lambda () (cvt* (cdr p*) n ids)) | |
2229 | (lambda (y ids) | |
2230 | (call-with-values | |
2231 | (lambda () (cvt (car p*) n ids)) | |
2232 | (lambda (x ids) | |
2233 | (values (cons x y) ids)))))))) | |
2234 | (define cvt | |
2235 | (lambda (p n ids) | |
2236 | (if (id? p) | |
2237 | (cond | |
2238 | ((bound-id-member? p keys) | |
2239 | (values (vector 'free-id p) ids)) | |
2240 | ((free-id=? p #'_) | |
2241 | (values '_ ids)) | |
2242 | (else | |
2243 | (values 'any (cons (cons p n) ids)))) | |
2244 | (syntax-case p () | |
2245 | ((x dots) | |
2246 | (ellipsis? (syntax dots)) | |
2247 | (call-with-values | |
2248 | (lambda () (cvt (syntax x) (fx+ n 1) ids)) | |
2249 | (lambda (p ids) | |
2250 | (values (if (eq? p 'any) 'each-any (vector 'each p)) | |
2251 | ids)))) | |
2252 | ((x dots ys ...) | |
2253 | (ellipsis? (syntax dots)) | |
2254 | (call-with-values | |
2255 | (lambda () (cvt* (syntax (ys ...)) n ids)) | |
2256 | (lambda (ys ids) | |
2257 | (call-with-values | |
2258 | (lambda () (cvt (syntax x) (+ n 1) ids)) | |
2259 | (lambda (x ids) | |
2260 | (values `#(each+ ,x ,(reverse ys) ()) ids)))))) | |
2261 | ((x . y) | |
2262 | (call-with-values | |
2263 | (lambda () (cvt (syntax y) n ids)) | |
2264 | (lambda (y ids) | |
2265 | (call-with-values | |
2266 | (lambda () (cvt (syntax x) n ids)) | |
2267 | (lambda (x ids) | |
2268 | (values (cons x y) ids)))))) | |
2269 | (() (values '() ids)) | |
2270 | (#(x ...) | |
2271 | (call-with-values | |
2272 | (lambda () (cvt (syntax (x ...)) n ids)) | |
2273 | (lambda (p ids) (values (vector 'vector p) ids)))) | |
2274 | (x (values (vector 'atom (strip p empty-wrap)) ids)))))) | |
2275 | (cvt pattern 0 '()))) | |
2276 | ||
2277 | (define build-dispatch-call | |
2278 | (lambda (pvars exp y r mod) | |
2279 | (let ((ids (map car pvars)) (levels (map cdr pvars))) | |
2280 | (let ((labels (gen-labels ids)) (new-vars (map gen-var ids))) | |
2281 | (build-application no-source | |
2282 | (build-primref no-source 'apply) | |
2283 | (list (build-simple-lambda no-source (map syntax->datum ids) #f new-vars '() | |
2284 | (chi exp | |
2285 | (extend-env | |
2286 | labels | |
2287 | (map (lambda (var level) | |
2288 | (make-binding 'syntax `(,var . ,level))) | |
2289 | new-vars | |
2290 | (map cdr pvars)) | |
2291 | r) | |
2292 | (make-binding-wrap ids labels empty-wrap) | |
2293 | mod)) | |
2294 | y)))))) | |
2295 | ||
2296 | (define gen-clause | |
2297 | (lambda (x keys clauses r pat fender exp mod) | |
2298 | (call-with-values | |
2299 | (lambda () (convert-pattern pat keys)) | |
2300 | (lambda (p pvars) | |
2301 | (cond | |
2302 | ((not (distinct-bound-ids? (map car pvars))) | |
2303 | (syntax-violation 'syntax-case "duplicate pattern variable" pat)) | |
2304 | ((not (and-map (lambda (x) (not (ellipsis? (car x)))) pvars)) | |
2305 | (syntax-violation 'syntax-case "misplaced ellipsis" pat)) | |
2306 | (else | |
2307 | (let ((y (gen-var 'tmp))) | |
2308 | ;; fat finger binding and references to temp variable y | |
2309 | (build-application no-source | |
2310 | (build-simple-lambda no-source (list 'tmp) #f (list y) '() | |
2311 | (let ((y (build-lexical-reference 'value no-source | |
2312 | 'tmp y))) | |
2313 | (build-conditional no-source | |
2314 | (syntax-case fender () | |
2315 | (#t y) | |
2316 | (_ (build-conditional no-source | |
2317 | y | |
2318 | (build-dispatch-call pvars fender y r mod) | |
2319 | (build-data no-source #f)))) | |
2320 | (build-dispatch-call pvars exp y r mod) | |
2321 | (gen-syntax-case x keys clauses r mod)))) | |
2322 | (list (if (eq? p 'any) | |
2323 | (build-application no-source | |
2324 | (build-primref no-source 'list) | |
2325 | (list x)) | |
2326 | (build-application no-source | |
2327 | (build-primref no-source '$sc-dispatch) | |
2328 | (list x (build-data no-source p))))))))))))) | |
2329 | ||
2330 | (define gen-syntax-case | |
2331 | (lambda (x keys clauses r mod) | |
2332 | (if (null? clauses) | |
2333 | (build-application no-source | |
2334 | (build-primref no-source 'syntax-violation) | |
2335 | (list (build-data no-source #f) | |
2336 | (build-data no-source | |
2337 | "source expression failed to match any pattern") | |
2338 | x)) | |
2339 | (syntax-case (car clauses) () | |
2340 | ((pat exp) | |
2341 | (if (and (id? #'pat) | |
2342 | (and-map (lambda (x) (not (free-id=? #'pat x))) | |
2343 | (cons #'(... ...) keys))) | |
2344 | (if (free-id=? #'pad #'_) | |
2345 | (chi #'exp r empty-wrap mod) | |
2346 | (let ((labels (list (gen-label))) | |
2347 | (var (gen-var #'pat))) | |
2348 | (build-application no-source | |
2349 | (build-simple-lambda | |
2350 | no-source (list (syntax->datum #'pat)) #f (list var) | |
2351 | '() | |
2352 | (chi #'exp | |
2353 | (extend-env labels | |
2354 | (list (make-binding 'syntax `(,var . 0))) | |
c3ae0ed4 | 2355 | r) |
8fad25c2 AW |
2356 | (make-binding-wrap #'(pat) |
2357 | labels empty-wrap) | |
2358 | mod)) | |
2359 | (list x)))) | |
2360 | (gen-clause x keys (cdr clauses) r | |
2361 | #'pat #t #'exp mod))) | |
2362 | ((pat fender exp) | |
2363 | (gen-clause x keys (cdr clauses) r | |
2364 | #'pat #'fender #'exp mod)) | |
2365 | (_ (syntax-violation 'syntax-case "invalid clause" | |
2366 | (car clauses))))))) | |
2367 | ||
2368 | (lambda (e r w s mod) | |
2369 | (let ((e (source-wrap e w s mod))) | |
2370 | (syntax-case e () | |
2371 | ((_ val (key ...) m ...) | |
2372 | (if (and-map (lambda (x) (and (id? x) (not (ellipsis? x)))) | |
2373 | #'(key ...)) | |
2374 | (let ((x (gen-var 'tmp))) | |
2375 | ;; fat finger binding and references to temp variable x | |
2376 | (build-application s | |
2377 | (build-simple-lambda no-source (list 'tmp) #f (list x) '() | |
2378 | (gen-syntax-case (build-lexical-reference 'value no-source | |
2379 | 'tmp x) | |
2380 | #'(key ...) #'(m ...) | |
2381 | r | |
2382 | mod)) | |
2383 | (list (chi #'val r empty-wrap mod)))) | |
2384 | (syntax-violation 'syntax-case "invalid literals list" e)))))))) | |
2385 | ||
2386 | ;; The portable macroexpand seeds chi-top's mode m with 'e (for | |
2387 | ;; evaluating) and esew (which stands for "eval syntax expanders | |
2388 | ;; when") with '(eval). In Chez Scheme, m is set to 'c instead of e | |
2389 | ;; if we are compiling a file, and esew is set to | |
2390 | ;; (eval-syntactic-expanders-when), which defaults to the list | |
2391 | ;; '(compile load eval). This means that, by default, top-level | |
2392 | ;; syntactic definitions are evaluated immediately after they are | |
2393 | ;; expanded, and the expanded definitions are also residualized into | |
2394 | ;; the object file if we are compiling a file. | |
2395 | (set! macroexpand | |
2396 | (lambda* (x #:optional (m 'e) (esew '(eval))) | |
4c2e13e5 AW |
2397 | (chi-top-sequence (list x) null-env top-wrap #f m esew |
2398 | (cons 'hygiene (module-name (current-module)))))) | |
8fad25c2 AW |
2399 | |
2400 | (set! identifier? | |
2401 | (lambda (x) | |
2402 | (nonsymbol-id? x))) | |
2403 | ||
2404 | (set! datum->syntax | |
2405 | (lambda (id datum) | |
2406 | (make-syntax-object datum (syntax-object-wrap id) | |
2407 | (syntax-object-module id)))) | |
2408 | ||
2409 | (set! syntax->datum | |
2410 | ;; accepts any object, since syntax objects may consist partially | |
2411 | ;; or entirely of unwrapped, nonsymbolic data | |
2412 | (lambda (x) | |
2413 | (strip x empty-wrap))) | |
2414 | ||
2415 | (set! syntax-source | |
2416 | (lambda (x) (source-annotation x))) | |
2417 | ||
2418 | (set! generate-temporaries | |
2419 | (lambda (ls) | |
2420 | (arg-check list? ls 'generate-temporaries) | |
2421 | (map (lambda (x) (wrap (gensym-hook) top-wrap #f)) ls))) | |
2422 | ||
2423 | (set! free-identifier=? | |
2424 | (lambda (x y) | |
2425 | (arg-check nonsymbol-id? x 'free-identifier=?) | |
2426 | (arg-check nonsymbol-id? y 'free-identifier=?) | |
2427 | (free-id=? x y))) | |
2428 | ||
2429 | (set! bound-identifier=? | |
2430 | (lambda (x y) | |
2431 | (arg-check nonsymbol-id? x 'bound-identifier=?) | |
2432 | (arg-check nonsymbol-id? y 'bound-identifier=?) | |
2433 | (bound-id=? x y))) | |
2434 | ||
2435 | (set! syntax-violation | |
8f1870f2 | 2436 | (lambda* (who message form #:optional subform) |
8fad25c2 AW |
2437 | (arg-check (lambda (x) (or (not x) (string? x) (symbol? x))) |
2438 | who 'syntax-violation) | |
2439 | (arg-check string? message 'syntax-violation) | |
8f1870f2 AW |
2440 | (throw 'syntax-error who message |
2441 | (source-annotation (or form subform)) | |
2442 | (strip form empty-wrap) | |
2443 | (and subform (strip subform empty-wrap))))) | |
8fad25c2 AW |
2444 | |
2445 | ;; $sc-dispatch expects an expression and a pattern. If the expression | |
2446 | ;; matches the pattern a list of the matching expressions for each | |
2447 | ;; "any" is returned. Otherwise, #f is returned. (This use of #f will | |
2448 | ;; not work on r4rs implementations that violate the ieee requirement | |
2449 | ;; that #f and () be distinct.) | |
2450 | ||
2451 | ;; The expression is matched with the pattern as follows: | |
2452 | ||
2453 | ;; pattern: matches: | |
2454 | ;; () empty list | |
2455 | ;; any anything | |
2456 | ;; (<pattern>1 . <pattern>2) (<pattern>1 . <pattern>2) | |
2457 | ;; each-any (any*) | |
2458 | ;; #(free-id <key>) <key> with free-identifier=? | |
2459 | ;; #(each <pattern>) (<pattern>*) | |
2460 | ;; #(each+ p1 (p2_1 ... p2_n) p3) (p1* (p2_n ... p2_1) . p3) | |
2461 | ;; #(vector <pattern>) (list->vector <pattern>) | |
2462 | ;; #(atom <object>) <object> with "equal?" | |
2463 | ||
2464 | ;; Vector cops out to pair under assumption that vectors are rare. If | |
2465 | ;; not, should convert to: | |
2466 | ;; #(vector <pattern>*) #(<pattern>*) | |
2467 | ||
2468 | (let () | |
2469 | ||
2470 | (define match-each | |
2471 | (lambda (e p w mod) | |
aa3819aa AR |
2472 | (cond |
2473 | ((pair? e) | |
8fad25c2 AW |
2474 | (let ((first (match (car e) p w '() mod))) |
2475 | (and first | |
2476 | (let ((rest (match-each (cdr e) p w mod))) | |
2477 | (and rest (cons first rest)))))) | |
2478 | ((null? e) '()) | |
aa3819aa | 2479 | ((syntax-object? e) |
8fad25c2 AW |
2480 | (match-each (syntax-object-expression e) |
2481 | p | |
2482 | (join-wraps w (syntax-object-wrap e)) | |
2483 | (syntax-object-module e))) | |
2484 | (else #f)))) | |
2485 | ||
2486 | (define match-each+ | |
2487 | (lambda (e x-pat y-pat z-pat w r mod) | |
2488 | (let f ((e e) (w w)) | |
c3ae0ed4 | 2489 | (cond |
8fad25c2 AW |
2490 | ((pair? e) |
2491 | (call-with-values (lambda () (f (cdr e) w)) | |
2492 | (lambda (xr* y-pat r) | |
2493 | (if r | |
2494 | (if (null? y-pat) | |
2495 | (let ((xr (match (car e) x-pat w '() mod))) | |
2496 | (if xr | |
2497 | (values (cons xr xr*) y-pat r) | |
2498 | (values #f #f #f))) | |
2499 | (values | |
2500 | '() | |
2501 | (cdr y-pat) | |
2502 | (match (car e) (car y-pat) w r mod))) | |
2503 | (values #f #f #f))))) | |
c3ae0ed4 | 2504 | ((syntax-object? e) |
8fad25c2 AW |
2505 | (f (syntax-object-expression e) (join-wraps w e))) |
2506 | (else | |
2507 | (values '() y-pat (match e z-pat w r mod))))))) | |
2508 | ||
2509 | (define match-each-any | |
2510 | (lambda (e w mod) | |
2511 | (cond | |
2512 | ((pair? e) | |
2513 | (let ((l (match-each-any (cdr e) w mod))) | |
2514 | (and l (cons (wrap (car e) w mod) l)))) | |
2515 | ((null? e) '()) | |
2516 | ((syntax-object? e) | |
2517 | (match-each-any (syntax-object-expression e) | |
2518 | (join-wraps w (syntax-object-wrap e)) | |
2519 | mod)) | |
2520 | (else #f)))) | |
2521 | ||
2522 | (define match-empty | |
2523 | (lambda (p r) | |
2524 | (cond | |
2525 | ((null? p) r) | |
2526 | ((eq? p '_) r) | |
2527 | ((eq? p 'any) (cons '() r)) | |
2528 | ((pair? p) (match-empty (car p) (match-empty (cdr p) r))) | |
2529 | ((eq? p 'each-any) (cons '() r)) | |
2530 | (else | |
2531 | (case (vector-ref p 0) | |
2532 | ((each) (match-empty (vector-ref p 1) r)) | |
2533 | ((each+) (match-empty (vector-ref p 1) | |
2534 | (match-empty | |
2535 | (reverse (vector-ref p 2)) | |
2536 | (match-empty (vector-ref p 3) r)))) | |
2537 | ((free-id atom) r) | |
2538 | ((vector) (match-empty (vector-ref p 1) r))))))) | |
2539 | ||
2540 | (define combine | |
2541 | (lambda (r* r) | |
2542 | (if (null? (car r*)) | |
2543 | r | |
2544 | (cons (map car r*) (combine (map cdr r*) r))))) | |
2545 | ||
2546 | (define match* | |
2547 | (lambda (e p w r mod) | |
2548 | (cond | |
2549 | ((null? p) (and (null? e) r)) | |
2550 | ((pair? p) | |
2551 | (and (pair? e) (match (car e) (car p) w | |
2552 | (match (cdr e) (cdr p) w r mod) | |
2553 | mod))) | |
2554 | ((eq? p 'each-any) | |
2555 | (let ((l (match-each-any e w mod))) (and l (cons l r)))) | |
2556 | (else | |
2557 | (case (vector-ref p 0) | |
2558 | ((each) | |
2559 | (if (null? e) | |
2560 | (match-empty (vector-ref p 1) r) | |
2561 | (let ((l (match-each e (vector-ref p 1) w mod))) | |
2562 | (and l | |
2563 | (let collect ((l l)) | |
2564 | (if (null? (car l)) | |
2565 | r | |
2566 | (cons (map car l) (collect (map cdr l))))))))) | |
2567 | ((each+) | |
2568 | (call-with-values | |
2569 | (lambda () | |
2570 | (match-each+ e (vector-ref p 1) (vector-ref p 2) (vector-ref p 3) w r mod)) | |
2571 | (lambda (xr* y-pat r) | |
2572 | (and r | |
2573 | (null? y-pat) | |
2574 | (if (null? xr*) | |
2575 | (match-empty (vector-ref p 1) r) | |
2576 | (combine xr* r)))))) | |
2577 | ((free-id) (and (id? e) (free-id=? (wrap e w mod) (vector-ref p 1)) r)) | |
2578 | ((atom) (and (equal? (vector-ref p 1) (strip e w)) r)) | |
2579 | ((vector) | |
2580 | (and (vector? e) | |
2581 | (match (vector->list e) (vector-ref p 1) w r mod)))))))) | |
2582 | ||
2583 | (define match | |
2584 | (lambda (e p w r mod) | |
2585 | (cond | |
2586 | ((not r) #f) | |
2587 | ((eq? p '_) r) | |
2588 | ((eq? p 'any) (cons (wrap e w mod) r)) | |
2589 | ((syntax-object? e) | |
2590 | (match* | |
2591 | (syntax-object-expression e) | |
2592 | p | |
2593 | (join-wraps w (syntax-object-wrap e)) | |
2594 | r | |
2595 | (syntax-object-module e))) | |
2596 | (else (match* e p w r mod))))) | |
2597 | ||
2598 | (set! $sc-dispatch | |
2599 | (lambda (e p) | |
2600 | (cond | |
2601 | ((eq? p 'any) (list e)) | |
2602 | ((eq? p '_) '()) | |
2603 | ((syntax-object? e) | |
2604 | (match* (syntax-object-expression e) | |
2605 | p (syntax-object-wrap e) '() (syntax-object-module e))) | |
2606 | (else (match* e p empty-wrap '() #f)))))))) | |
80f225df | 2607 | |
a63812a2 JB |
2608 | |
2609 | (define-syntax with-syntax | |
2610 | (lambda (x) | |
2611 | (syntax-case x () | |
2612 | ((_ () e1 e2 ...) | |
c3ae0ed4 | 2613 | #'(begin e1 e2 ...)) |
a63812a2 | 2614 | ((_ ((out in)) e1 e2 ...) |
c3ae0ed4 | 2615 | #'(syntax-case in () (out (begin e1 e2 ...)))) |
a63812a2 | 2616 | ((_ ((out in) ...) e1 e2 ...) |
c3ae0ed4 AW |
2617 | #'(syntax-case (list in ...) () |
2618 | ((out ...) (begin e1 e2 ...))))))) | |
a63812a2 JB |
2619 | |
2620 | (define-syntax syntax-rules | |
2621 | (lambda (x) | |
2622 | (syntax-case x () | |
2623 | ((_ (k ...) ((keyword . pattern) template) ...) | |
c3ae0ed4 | 2624 | #'(lambda (x) |
a5e95abe | 2625 | ;; embed patterns as procedure metadata |
44d65b23 AW |
2626 | #((macro-type . syntax-rules) |
2627 | (patterns pattern ...)) | |
2628 | (syntax-case x (k ...) | |
2629 | ((dummy . pattern) #'template) | |
2630 | ...))) | |
2631 | ((_ (k ...) docstring ((keyword . pattern) template) ...) | |
2632 | (string? (syntax->datum #'docstring)) | |
2633 | #'(lambda (x) | |
2634 | ;; the same, but allow a docstring | |
2635 | docstring | |
a5e95abe AW |
2636 | #((macro-type . syntax-rules) |
2637 | (patterns pattern ...)) | |
c3ae0ed4 AW |
2638 | (syntax-case x (k ...) |
2639 | ((dummy . pattern) #'template) | |
2640 | ...)))))) | |
a63812a2 JB |
2641 | |
2642 | (define-syntax let* | |
2643 | (lambda (x) | |
2644 | (syntax-case x () | |
2645 | ((let* ((x v) ...) e1 e2 ...) | |
c3ae0ed4 AW |
2646 | (and-map identifier? #'(x ...)) |
2647 | (let f ((bindings #'((x v) ...))) | |
a63812a2 | 2648 | (if (null? bindings) |
c3ae0ed4 | 2649 | #'(let () e1 e2 ...) |
a63812a2 JB |
2650 | (with-syntax ((body (f (cdr bindings))) |
2651 | (binding (car bindings))) | |
c3ae0ed4 | 2652 | #'(let (binding) body)))))))) |
a63812a2 JB |
2653 | |
2654 | (define-syntax do | |
2655 | (lambda (orig-x) | |
2656 | (syntax-case orig-x () | |
2657 | ((_ ((var init . step) ...) (e0 e1 ...) c ...) | |
2658 | (with-syntax (((step ...) | |
2659 | (map (lambda (v s) | |
c3ae0ed4 AW |
2660 | (syntax-case s () |
2661 | (() v) | |
2662 | ((e) #'e) | |
2663 | (_ (syntax-violation | |
2664 | 'do "bad step expression" | |
2665 | orig-x s)))) | |
2666 | #'(var ...) | |
2667 | #'(step ...)))) | |
2668 | (syntax-case #'(e1 ...) () | |
2669 | (() #'(let doloop ((var init) ...) | |
2670 | (if (not e0) | |
2671 | (begin c ... (doloop step ...))))) | |
2672 | ((e1 e2 ...) | |
2673 | #'(let doloop ((var init) ...) | |
2674 | (if e0 | |
2675 | (begin e1 e2 ...) | |
2676 | (begin c ... (doloop step ...))))))))))) | |
a63812a2 JB |
2677 | |
2678 | (define-syntax quasiquote | |
0f550375 AW |
2679 | (let () |
2680 | (define (quasi p lev) | |
2681 | (syntax-case p (unquote quasiquote) | |
2682 | ((unquote p) | |
2683 | (if (= lev 0) | |
2684 | #'("value" p) | |
2685 | (quasicons #'("quote" unquote) (quasi #'(p) (- lev 1))))) | |
2686 | ((quasiquote p) (quasicons #'("quote" quasiquote) (quasi #'(p) (+ lev 1)))) | |
2687 | ((p . q) | |
2688 | (syntax-case #'p (unquote unquote-splicing) | |
2689 | ((unquote p ...) | |
2690 | (if (= lev 0) | |
2691 | (quasilist* #'(("value" p) ...) (quasi #'q lev)) | |
2692 | (quasicons | |
2693 | (quasicons #'("quote" unquote) (quasi #'(p ...) (- lev 1))) | |
2694 | (quasi #'q lev)))) | |
2695 | ((unquote-splicing p ...) | |
2696 | (if (= lev 0) | |
2697 | (quasiappend #'(("value" p) ...) (quasi #'q lev)) | |
2698 | (quasicons | |
2699 | (quasicons #'("quote" unquote-splicing) (quasi #'(p ...) (- lev 1))) | |
2700 | (quasi #'q lev)))) | |
2701 | (_ (quasicons (quasi #'p lev) (quasi #'q lev))))) | |
2702 | (#(x ...) (quasivector (vquasi #'(x ...) lev))) | |
2703 | (p #'("quote" p)))) | |
2704 | (define (vquasi p lev) | |
2705 | (syntax-case p () | |
2706 | ((p . q) | |
2707 | (syntax-case #'p (unquote unquote-splicing) | |
2708 | ((unquote p ...) | |
2709 | (if (= lev 0) | |
2710 | (quasilist* #'(("value" p) ...) (vquasi #'q lev)) | |
2711 | (quasicons | |
2712 | (quasicons #'("quote" unquote) (quasi #'(p ...) (- lev 1))) | |
2713 | (vquasi #'q lev)))) | |
2714 | ((unquote-splicing p ...) | |
2715 | (if (= lev 0) | |
2716 | (quasiappend #'(("value" p) ...) (vquasi #'q lev)) | |
2717 | (quasicons | |
2718 | (quasicons | |
2719 | #'("quote" unquote-splicing) | |
2720 | (quasi #'(p ...) (- lev 1))) | |
2721 | (vquasi #'q lev)))) | |
2722 | (_ (quasicons (quasi #'p lev) (vquasi #'q lev))))) | |
2723 | (() #'("quote" ())))) | |
2724 | (define (quasicons x y) | |
2725 | (with-syntax ((x x) (y y)) | |
2726 | (syntax-case #'y () | |
2727 | (("quote" dy) | |
2728 | (syntax-case #'x () | |
2729 | (("quote" dx) #'("quote" (dx . dy))) | |
2730 | (_ (if (null? #'dy) #'("list" x) #'("list*" x y))))) | |
2731 | (("list" . stuff) #'("list" x . stuff)) | |
2732 | (("list*" . stuff) #'("list*" x . stuff)) | |
2733 | (_ #'("list*" x y))))) | |
2734 | (define (quasiappend x y) | |
2735 | (syntax-case y () | |
2736 | (("quote" ()) | |
2737 | (cond | |
2738 | ((null? x) #'("quote" ())) | |
2739 | ((null? (cdr x)) (car x)) | |
2740 | (else (with-syntax (((p ...) x)) #'("append" p ...))))) | |
2741 | (_ | |
2742 | (cond | |
2743 | ((null? x) y) | |
2744 | (else (with-syntax (((p ...) x) (y y)) #'("append" p ... y))))))) | |
2745 | (define (quasilist* x y) | |
2746 | (let f ((x x)) | |
2747 | (if (null? x) | |
2748 | y | |
2749 | (quasicons (car x) (f (cdr x)))))) | |
2750 | (define (quasivector x) | |
2751 | (syntax-case x () | |
2752 | (("quote" (x ...)) #'("quote" #(x ...))) | |
2753 | (_ | |
2754 | (let f ((y x) (k (lambda (ls) #`("vector" #,@ls)))) | |
2755 | (syntax-case y () | |
2756 | (("quote" (y ...)) (k #'(("quote" y) ...))) | |
2757 | (("list" y ...) (k #'(y ...))) | |
2758 | (("list*" y ... z) (f #'z (lambda (ls) (k (append #'(y ...) ls))))) | |
2759 | (else #`("list->vector" #,x))))))) | |
2760 | (define (emit x) | |
2761 | (syntax-case x () | |
2762 | (("quote" x) #''x) | |
2763 | (("list" x ...) #`(list #,@(map emit #'(x ...)))) | |
2764 | ;; could emit list* for 3+ arguments if implementation supports | |
2765 | ;; list* | |
2766 | (("list*" x ... y) | |
2767 | (let f ((x* #'(x ...))) | |
2768 | (if (null? x*) | |
2769 | (emit #'y) | |
2770 | #`(cons #,(emit (car x*)) #,(f (cdr x*)))))) | |
2771 | (("append" x ...) #`(append #,@(map emit #'(x ...)))) | |
2772 | (("vector" x ...) #`(vector #,@(map emit #'(x ...)))) | |
2773 | (("list->vector" x) #`(list->vector #,(emit #'x))) | |
2774 | (("value" x) #'x))) | |
a63812a2 | 2775 | (lambda (x) |
0f550375 AW |
2776 | (syntax-case x () |
2777 | ;; convert to intermediate language, combining introduced (but | |
2778 | ;; not unquoted source) quote expressions where possible and | |
2779 | ;; choosing optimal construction code otherwise, then emit | |
2780 | ;; Scheme code corresponding to the intermediate language forms. | |
2781 | ((_ e) (emit (quasi #'e 0))))))) | |
a63812a2 JB |
2782 | |
2783 | (define-syntax include | |
2784 | (lambda (x) | |
2785 | (define read-file | |
2786 | (lambda (fn k) | |
2787 | (let ((p (open-input-file fn))) | |
df0f5295 LC |
2788 | (let f ((x (read p)) |
2789 | (result '())) | |
a63812a2 | 2790 | (if (eof-object? x) |
df0f5295 LC |
2791 | (begin |
2792 | (close-input-port p) | |
2793 | (reverse result)) | |
2794 | (f (read p) | |
2795 | (cons (datum->syntax k x) result))))))) | |
a63812a2 JB |
2796 | (syntax-case x () |
2797 | ((k filename) | |
c3ae0ed4 | 2798 | (let ((fn (syntax->datum #'filename))) |
9846796b | 2799 | (with-syntax (((exp ...) (read-file fn #'filename))) |
c3ae0ed4 | 2800 | #'(begin exp ...))))))) |
a63812a2 | 2801 | |
d89fae24 AW |
2802 | (define-syntax include-from-path |
2803 | (lambda (x) | |
2804 | (syntax-case x () | |
2805 | ((k filename) | |
2806 | (let ((fn (syntax->datum #'filename))) | |
9846796b AW |
2807 | (with-syntax ((fn (datum->syntax |
2808 | #'filename | |
2809 | (or (%search-load-path fn) | |
2810 | (syntax-violation 'include-from-path | |
2811 | "file not found in path" | |
2812 | x #'filename))))) | |
d89fae24 AW |
2813 | #'(include fn))))))) |
2814 | ||
a63812a2 | 2815 | (define-syntax unquote |
6a952e0e | 2816 | (lambda (x) |
0f550375 AW |
2817 | (syntax-violation 'unquote |
2818 | "expression not valid outside of quasiquote" | |
2819 | x))) | |
a63812a2 JB |
2820 | |
2821 | (define-syntax unquote-splicing | |
6a952e0e | 2822 | (lambda (x) |
0f550375 AW |
2823 | (syntax-violation 'unquote-splicing |
2824 | "expression not valid outside of quasiquote" | |
2825 | x))) | |
a63812a2 JB |
2826 | |
2827 | (define-syntax case | |
2828 | (lambda (x) | |
2829 | (syntax-case x () | |
2830 | ((_ e m1 m2 ...) | |
2831 | (with-syntax | |
c3ae0ed4 AW |
2832 | ((body (let f ((clause #'m1) (clauses #'(m2 ...))) |
2833 | (if (null? clauses) | |
a63812a2 | 2834 | (syntax-case clause (else) |
c3ae0ed4 | 2835 | ((else e1 e2 ...) #'(begin e1 e2 ...)) |
a63812a2 | 2836 | (((k ...) e1 e2 ...) |
c3ae0ed4 AW |
2837 | #'(if (memv t '(k ...)) (begin e1 e2 ...))) |
2838 | (_ (syntax-violation 'case "bad clause" x clause))) | |
2839 | (with-syntax ((rest (f (car clauses) (cdr clauses)))) | |
2840 | (syntax-case clause (else) | |
2841 | (((k ...) e1 e2 ...) | |
2842 | #'(if (memv t '(k ...)) | |
2843 | (begin e1 e2 ...) | |
2844 | rest)) | |
2845 | (_ (syntax-violation 'case "bad clause" x | |
2846 | clause)))))))) | |
2847 | #'(let ((t e)) body)))))) | |
a63812a2 | 2848 | |
bfccdcd5 AW |
2849 | (define (make-variable-transformer proc) |
2850 | (if (procedure? proc) | |
2851 | (let ((trans (lambda (x) | |
2852 | #((macro-type . variable-transformer)) | |
2853 | (proc x)))) | |
2854 | (set-procedure-property! trans 'variable-transformer #t) | |
2855 | trans) | |
2856 | (error "variable transformer not a procedure" proc))) | |
2857 | ||
a63812a2 JB |
2858 | (define-syntax identifier-syntax |
2859 | (lambda (x) | |
bfccdcd5 | 2860 | (syntax-case x (set!) |
a63812a2 | 2861 | ((_ e) |
c3ae0ed4 | 2862 | #'(lambda (x) |
a5e95abe | 2863 | #((macro-type . identifier-syntax)) |
a63812a2 JB |
2864 | (syntax-case x () |
2865 | (id | |
c3ae0ed4 AW |
2866 | (identifier? #'id) |
2867 | #'e) | |
a63812a2 | 2868 | ((_ x (... ...)) |
bfccdcd5 AW |
2869 | #'(e x (... ...)))))) |
2870 | ((_ (id exp1) ((set! var val) exp2)) | |
2871 | (and (identifier? #'id) (identifier? #'var)) | |
2872 | #'(make-variable-transformer | |
2873 | (lambda (x) | |
2874 | #((macro-type . variable-transformer)) | |
2875 | (syntax-case x (set!) | |
2876 | ((set! var val) #'exp2) | |
2877 | ((id x (... ...)) #'(exp1 x (... ...))) | |
2878 | (id (identifier? #'id) #'exp1)))))))) | |
97bc28b6 AW |
2879 | |
2880 | (define-syntax define* | |
64fa96ef AW |
2881 | (lambda (x) |
2882 | (syntax-case x () | |
2883 | ((_ (id . args) b0 b1 ...) | |
2884 | #'(define id (lambda* args b0 b1 ...))) | |
2885 | ((_ id val) (identifier? #'x) | |
2886 | #'(define id val))))) |