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dc3e203e AW |
1 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010 |
2 | * Free Software Foundation, Inc. | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU Lesser General Public License | |
6 | * as published by the Free Software Foundation; either version 3 of | |
7 | * the License, or (at your option) any later version. | |
8 | * | |
9 | * This library is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * Lesser General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public | |
15 | * License along with this library; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
17 | * 02110-1301 USA | |
18 | */ | |
19 | ||
20 | \f | |
21 | ||
22 | #ifdef HAVE_CONFIG_H | |
23 | # include <config.h> | |
24 | #endif | |
25 | ||
26 | #include "libguile/__scm.h" | |
27 | #include "libguile/_scm.h" | |
28 | #include "libguile/continuations.h" | |
29 | #include "libguile/eq.h" | |
30 | #include "libguile/list.h" | |
31 | #include "libguile/macros.h" | |
32 | #include "libguile/expand.h" | |
33 | #include "libguile/modules.h" | |
34 | #include "libguile/srcprop.h" | |
35 | #include "libguile/ports.h" | |
36 | #include "libguile/print.h" | |
37 | #include "libguile/strings.h" | |
38 | #include "libguile/throw.h" | |
39 | #include "libguile/validate.h" | |
40 | ||
41 | ||
42 | \f | |
43 | ||
44 | ||
45 | SCM scm_exp_vtable_vtable; | |
46 | static SCM exp_vtables[SCM_NUM_EXPANDED_TYPES]; | |
47 | static size_t exp_nfields[SCM_NUM_EXPANDED_TYPES]; | |
48 | static const char* exp_names[SCM_NUM_EXPANDED_TYPES]; | |
49 | static const char** exp_field_names[SCM_NUM_EXPANDED_TYPES]; | |
50 | ||
51 | ||
52 | #define VOID(src) \ | |
53 | SCM_MAKE_EXPANDED_VOID(src) | |
54 | #define CONST(src, exp) \ | |
55 | SCM_MAKE_EXPANDED_CONST(src, exp) | |
56 | #define PRIMITIVE_REF_TYPE(src, name) \ | |
57 | SCM_MAKE_EXPANDED_PRIMITIVE_REF_TYPE(src, name) | |
58 | #define LEXICAL_REF(src, name, gensym) \ | |
59 | SCM_MAKE_EXPANDED_LEXICAL_REF(src, name, gensym) | |
60 | #define LEXICAL_SET(src, name, gensym, exp) \ | |
61 | SCM_MAKE_EXPANDED_LEXICAL_SET(src, name, gensym, exp) | |
62 | #define MODULE_REF(src, mod, name, public) \ | |
63 | SCM_MAKE_EXPANDED_MODULE_REF(src, mod, name, public) | |
64 | #define MODULE_SET(src, mod, name, public, exp) \ | |
65 | SCM_MAKE_EXPANDED_MODULE_SET(src, mod, name, public, exp) | |
66 | #define TOPLEVEL_REF(src, name) \ | |
67 | SCM_MAKE_EXPANDED_TOPLEVEL_REF(src, name) | |
68 | #define TOPLEVEL_SET(src, name, exp) \ | |
69 | SCM_MAKE_EXPANDED_TOPLEVEL_SET(src, name, exp) | |
70 | #define TOPLEVEL_DEFINE(src, name, exp) \ | |
71 | SCM_MAKE_EXPANDED_TOPLEVEL_DEFINE(src, name, exp) | |
72 | #define CONDITIONAL(src, test, consequent, alternate) \ | |
73 | SCM_MAKE_EXPANDED_CONDITIONAL(src, test, consequent, alternate) | |
74 | #define APPLICATION(src, proc, exps) \ | |
75 | SCM_MAKE_EXPANDED_APPLICATION(src, proc, exps) | |
76 | #define SEQUENCE(src, exps) \ | |
77 | SCM_MAKE_EXPANDED_SEQUENCE(src, exps) | |
78 | #define LAMBDA(src, meta, body) \ | |
79 | SCM_MAKE_EXPANDED_LAMBDA(src, meta, body) | |
80 | #define LAMBDA_CASE(src, req, opt, rest, kw, inits, gensyms, body, alternate) \ | |
81 | SCM_MAKE_EXPANDED_LAMBDA_CASE(src, req, opt, rest, kw, inits, gensyms, body, alternate) | |
82 | #define LET(src, names, gensyms, vals, body) \ | |
83 | SCM_MAKE_EXPANDED_LET(src, names, gensyms, vals, body) | |
fb6e61ca AW |
84 | #define LETREC(src, in_order_p, names, gensyms, vals, body) \ |
85 | SCM_MAKE_EXPANDED_LETREC(src, in_order_p, names, gensyms, vals, body) | |
dc3e203e AW |
86 | #define DYNLET(src, fluids, vals, body) \ |
87 | SCM_MAKE_EXPANDED_DYNLET(src, fluids, vals, body) | |
88 | ||
89 | #define CAR(x) SCM_CAR(x) | |
90 | #define CDR(x) SCM_CDR(x) | |
91 | #define CAAR(x) SCM_CAAR(x) | |
92 | #define CADR(x) SCM_CADR(x) | |
93 | #define CDAR(x) SCM_CDAR(x) | |
94 | #define CDDR(x) SCM_CDDR(x) | |
95 | #define CADDR(x) SCM_CADDR(x) | |
96 | #define CDDDR(x) SCM_CDDDR(x) | |
97 | #define CADDDR(x) SCM_CADDDR(x) | |
98 | ||
99 | ||
100 | static const char s_bad_expression[] = "Bad expression"; | |
101 | static const char s_expression[] = "Missing or extra expression in"; | |
102 | static const char s_missing_expression[] = "Missing expression in"; | |
103 | static const char s_extra_expression[] = "Extra expression in"; | |
104 | static const char s_empty_combination[] = "Illegal empty combination"; | |
105 | static const char s_missing_body_expression[] = "Missing body expression in"; | |
106 | static const char s_mixed_body_forms[] = "Mixed definitions and expressions in"; | |
107 | static const char s_bad_define[] = "Bad define placement"; | |
108 | static const char s_missing_clauses[] = "Missing clauses"; | |
109 | static const char s_misplaced_else_clause[] = "Misplaced else clause"; | |
110 | static const char s_bad_case_clause[] = "Bad case clause"; | |
111 | static const char s_bad_case_labels[] = "Bad case labels"; | |
112 | static const char s_duplicate_case_label[] = "Duplicate case label"; | |
113 | static const char s_bad_cond_clause[] = "Bad cond clause"; | |
114 | static const char s_missing_recipient[] = "Missing recipient in"; | |
115 | static const char s_bad_variable[] = "Bad variable"; | |
116 | static const char s_bad_bindings[] = "Bad bindings"; | |
117 | static const char s_bad_binding[] = "Bad binding"; | |
118 | static const char s_duplicate_binding[] = "Duplicate binding"; | |
119 | static const char s_bad_exit_clause[] = "Bad exit clause"; | |
120 | static const char s_bad_formals[] = "Bad formals"; | |
121 | static const char s_bad_formal[] = "Bad formal"; | |
122 | static const char s_duplicate_formal[] = "Duplicate formal"; | |
123 | static const char s_splicing[] = "Non-list result for unquote-splicing"; | |
124 | static const char s_bad_slot_number[] = "Bad slot number"; | |
125 | ||
126 | static void syntax_error (const char* const, const SCM, const SCM) SCM_NORETURN; | |
127 | ||
128 | SCM_SYMBOL (syntax_error_key, "syntax-error"); | |
129 | ||
130 | /* Shortcut macros to simplify syntax error handling. */ | |
131 | #define ASSERT_SYNTAX(cond, message, form) \ | |
132 | { if (SCM_UNLIKELY (!(cond))) \ | |
133 | syntax_error (message, form, SCM_UNDEFINED); } | |
134 | #define ASSERT_SYNTAX_2(cond, message, form, expr) \ | |
135 | { if (SCM_UNLIKELY (!(cond))) \ | |
136 | syntax_error (message, form, expr); } | |
137 | ||
138 | ||
139 | \f | |
140 | ||
141 | /* Primitive syntax. */ | |
142 | ||
143 | #define SCM_SYNTAX(STR, CFN) \ | |
144 | SCM_SNARF_HERE(static SCM CFN (SCM xorig, SCM env)) \ | |
145 | SCM_SNARF_INIT(scm_c_define (STR, scm_i_make_primitive_macro (STR, CFN))) | |
146 | ||
147 | ||
148 | /* True primitive syntax */ | |
149 | SCM_SYNTAX ("@", expand_at); | |
150 | SCM_SYNTAX ("@@", expand_atat); | |
151 | SCM_SYNTAX ("begin", expand_begin); | |
152 | SCM_SYNTAX ("define", expand_define); | |
153 | SCM_SYNTAX ("with-fluids", expand_with_fluids); | |
154 | SCM_SYNTAX ("eval-when", expand_eval_when); | |
155 | SCM_SYNTAX ("if", expand_if); | |
156 | SCM_SYNTAX ("lambda", expand_lambda); | |
157 | SCM_SYNTAX ("let", expand_let); | |
158 | SCM_SYNTAX ("quote", expand_quote); | |
159 | SCM_SYNTAX ("set!", expand_set_x); | |
160 | ||
161 | /* Convenient syntax during boot, expands to primitive syntax. Replaced after | |
162 | psyntax boots. */ | |
163 | SCM_SYNTAX ("and", expand_and); | |
164 | SCM_SYNTAX ("cond", expand_cond); | |
165 | SCM_SYNTAX ("letrec", expand_letrec); | |
826373a2 | 166 | SCM_SYNTAX ("letrec*", expand_letrec_star); |
dc3e203e AW |
167 | SCM_SYNTAX ("let*", expand_letstar); |
168 | SCM_SYNTAX ("or", expand_or); | |
169 | SCM_SYNTAX ("lambda*", expand_lambda_star); | |
170 | SCM_SYNTAX ("case-lambda", expand_case_lambda); | |
171 | SCM_SYNTAX ("case-lambda*", expand_case_lambda_star); | |
172 | ||
173 | ||
174 | SCM_GLOBAL_SYMBOL (scm_sym_apply, "apply"); | |
175 | SCM_GLOBAL_SYMBOL (scm_sym_arrow, "=>"); | |
176 | SCM_GLOBAL_SYMBOL (scm_sym_at, "@"); | |
177 | SCM_GLOBAL_SYMBOL (scm_sym_atat, "@@"); | |
178 | SCM_GLOBAL_SYMBOL (scm_sym_at_call_with_values, "@call-with-values"); | |
179 | SCM_GLOBAL_SYMBOL (scm_sym_atapply, "@apply"); | |
180 | SCM_GLOBAL_SYMBOL (scm_sym_atcall_cc, "@call-with-current-continuation"); | |
181 | SCM_GLOBAL_SYMBOL (scm_sym_begin, "begin"); | |
182 | SCM_GLOBAL_SYMBOL (scm_sym_case, "case"); | |
183 | SCM_GLOBAL_SYMBOL (scm_sym_cond, "cond"); | |
184 | SCM_GLOBAL_SYMBOL (scm_sym_define, "define"); | |
185 | SCM_GLOBAL_SYMBOL (scm_sym_at_dynamic_wind, "@dynamic-wind"); | |
186 | SCM_GLOBAL_SYMBOL (scm_sym_with_fluids, "with-fluids"); | |
187 | SCM_GLOBAL_SYMBOL (scm_sym_else, "else"); | |
188 | SCM_GLOBAL_SYMBOL (scm_sym_eval_when, "eval-when"); | |
189 | SCM_GLOBAL_SYMBOL (scm_sym_if, "if"); | |
190 | SCM_GLOBAL_SYMBOL (scm_sym_lambda, "lambda"); | |
191 | SCM_GLOBAL_SYMBOL (scm_sym_let, "let"); | |
192 | SCM_GLOBAL_SYMBOL (scm_sym_letrec, "letrec"); | |
193 | SCM_GLOBAL_SYMBOL (scm_sym_letstar, "let*"); | |
194 | SCM_GLOBAL_SYMBOL (scm_sym_or, "or"); | |
195 | SCM_GLOBAL_SYMBOL (scm_sym_at_prompt, "@prompt"); | |
196 | SCM_GLOBAL_SYMBOL (scm_sym_quote, "quote"); | |
197 | SCM_GLOBAL_SYMBOL (scm_sym_set_x, "set!"); | |
198 | SCM_SYMBOL (sym_lambda_star, "lambda*"); | |
199 | SCM_SYMBOL (sym_eval, "eval"); | |
200 | SCM_SYMBOL (sym_load, "load"); | |
201 | ||
202 | SCM_GLOBAL_SYMBOL (scm_sym_unquote, "unquote"); | |
203 | SCM_GLOBAL_SYMBOL (scm_sym_quasiquote, "quasiquote"); | |
204 | SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing, "unquote-splicing"); | |
205 | ||
206 | SCM_KEYWORD (kw_allow_other_keys, "allow-other-keys"); | |
207 | SCM_KEYWORD (kw_optional, "optional"); | |
208 | SCM_KEYWORD (kw_key, "key"); | |
209 | SCM_KEYWORD (kw_rest, "rest"); | |
210 | ||
211 | ||
212 | \f | |
213 | ||
214 | ||
215 | /* Signal a syntax error. We distinguish between the form that caused the | |
216 | * error and the enclosing expression. The error message will print out as | |
217 | * shown in the following pattern. The file name and line number are only | |
218 | * given when they can be determined from the erroneous form or from the | |
219 | * enclosing expression. | |
220 | * | |
221 | * <filename>: In procedure memoization: | |
222 | * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */ | |
223 | ||
224 | static void | |
225 | syntax_error (const char* const msg, const SCM form, const SCM expr) | |
226 | { | |
227 | SCM msg_string = scm_from_locale_string (msg); | |
228 | SCM filename = SCM_BOOL_F; | |
229 | SCM linenr = SCM_BOOL_F; | |
230 | const char *format; | |
231 | SCM args; | |
232 | ||
233 | if (scm_is_pair (form)) | |
234 | { | |
235 | filename = scm_source_property (form, scm_sym_filename); | |
236 | linenr = scm_source_property (form, scm_sym_line); | |
237 | } | |
238 | ||
239 | if (scm_is_false (filename) && scm_is_false (linenr) && scm_is_pair (expr)) | |
240 | { | |
241 | filename = scm_source_property (expr, scm_sym_filename); | |
242 | linenr = scm_source_property (expr, scm_sym_line); | |
243 | } | |
244 | ||
245 | if (!SCM_UNBNDP (expr)) | |
246 | { | |
247 | if (scm_is_true (filename)) | |
248 | { | |
249 | format = "In file ~S, line ~S: ~A ~S in expression ~S."; | |
250 | args = scm_list_5 (filename, linenr, msg_string, form, expr); | |
251 | } | |
252 | else if (scm_is_true (linenr)) | |
253 | { | |
254 | format = "In line ~S: ~A ~S in expression ~S."; | |
255 | args = scm_list_4 (linenr, msg_string, form, expr); | |
256 | } | |
257 | else | |
258 | { | |
259 | format = "~A ~S in expression ~S."; | |
260 | args = scm_list_3 (msg_string, form, expr); | |
261 | } | |
262 | } | |
263 | else | |
264 | { | |
265 | if (scm_is_true (filename)) | |
266 | { | |
267 | format = "In file ~S, line ~S: ~A ~S."; | |
268 | args = scm_list_4 (filename, linenr, msg_string, form); | |
269 | } | |
270 | else if (scm_is_true (linenr)) | |
271 | { | |
272 | format = "In line ~S: ~A ~S."; | |
273 | args = scm_list_3 (linenr, msg_string, form); | |
274 | } | |
275 | else | |
276 | { | |
277 | format = "~A ~S."; | |
278 | args = scm_list_2 (msg_string, form); | |
279 | } | |
280 | } | |
281 | ||
282 | scm_error (syntax_error_key, "memoization", format, args, SCM_BOOL_F); | |
283 | } | |
284 | ||
285 | ||
286 | \f | |
287 | ||
288 | ||
289 | static int | |
290 | expand_env_var_is_free (SCM env, SCM x) | |
291 | { | |
292 | for (; scm_is_pair (env); env = CDR (env)) | |
293 | if (scm_is_eq (x, CAAR (env))) | |
294 | return 0; /* bound */ | |
295 | return 1; /* free */ | |
296 | } | |
297 | ||
298 | static SCM | |
299 | expand_env_ref_macro (SCM env, SCM x) | |
300 | { | |
301 | SCM var; | |
302 | if (!expand_env_var_is_free (env, x)) | |
303 | return SCM_BOOL_F; /* lexical */ | |
304 | ||
305 | var = scm_module_variable (scm_current_module (), x); | |
306 | if (scm_is_true (var) && scm_is_true (scm_variable_bound_p (var)) | |
307 | && scm_is_true (scm_macro_p (scm_variable_ref (var)))) | |
308 | return scm_variable_ref (var); | |
309 | else | |
310 | return SCM_BOOL_F; /* anything else */ | |
311 | } | |
312 | ||
313 | static SCM | |
314 | expand_env_lexical_gensym (SCM env, SCM name) | |
315 | { | |
316 | for (; scm_is_pair (env); env = CDR (env)) | |
317 | if (scm_is_eq (name, CAAR (env))) | |
318 | return CDAR (env); /* bound */ | |
319 | return SCM_BOOL_F; /* free */ | |
320 | } | |
321 | ||
322 | static SCM | |
323 | expand_env_extend (SCM env, SCM names, SCM vars) | |
324 | { | |
325 | while (scm_is_pair (names)) | |
326 | { | |
327 | env = scm_acons (CAR (names), CAR (vars), env); | |
328 | names = CDR (names); | |
329 | vars = CDR (vars); | |
330 | } | |
331 | return env; | |
332 | } | |
333 | ||
334 | static SCM | |
335 | expand (SCM exp, SCM env) | |
336 | { | |
337 | if (scm_is_pair (exp)) | |
338 | { | |
339 | SCM car; | |
340 | scm_t_macro_primitive trans = NULL; | |
341 | SCM macro = SCM_BOOL_F; | |
342 | ||
343 | car = CAR (exp); | |
344 | if (scm_is_symbol (car)) | |
345 | macro = expand_env_ref_macro (env, car); | |
346 | ||
347 | if (scm_is_true (macro)) | |
348 | trans = scm_i_macro_primitive (macro); | |
349 | ||
350 | if (trans) | |
351 | return trans (exp, env); | |
352 | else | |
353 | { | |
354 | SCM arg_exps = SCM_EOL; | |
355 | SCM args = SCM_EOL; | |
356 | SCM proc = CAR (exp); | |
357 | ||
358 | for (arg_exps = CDR (exp); scm_is_pair (arg_exps); | |
359 | arg_exps = CDR (arg_exps)) | |
360 | args = scm_cons (expand (CAR (arg_exps), env), args); | |
361 | if (scm_is_null (arg_exps)) | |
362 | return APPLICATION (scm_source_properties (exp), | |
363 | expand (proc, env), | |
364 | scm_reverse_x (args, SCM_UNDEFINED)); | |
365 | else | |
366 | syntax_error ("expected a proper list", exp, SCM_UNDEFINED); | |
367 | } | |
368 | } | |
369 | else if (scm_is_symbol (exp)) | |
370 | { | |
371 | SCM gensym = expand_env_lexical_gensym (env, exp); | |
372 | if (scm_is_true (gensym)) | |
373 | return LEXICAL_REF (SCM_BOOL_F, exp, gensym); | |
374 | else | |
375 | return TOPLEVEL_REF (SCM_BOOL_F, exp); | |
376 | } | |
377 | else | |
378 | return CONST (SCM_BOOL_F, exp); | |
379 | } | |
380 | ||
381 | static SCM | |
382 | expand_exprs (SCM forms, const SCM env) | |
383 | { | |
384 | SCM ret = SCM_EOL; | |
385 | ||
386 | for (; !scm_is_null (forms); forms = CDR (forms)) | |
387 | ret = scm_cons (expand (CAR (forms), env), ret); | |
388 | return scm_reverse_x (ret, SCM_UNDEFINED); | |
389 | } | |
390 | ||
391 | static SCM | |
392 | expand_sequence (const SCM forms, const SCM env) | |
393 | { | |
394 | ASSERT_SYNTAX (scm_ilength (forms) >= 1, s_bad_expression, | |
395 | scm_cons (scm_sym_begin, forms)); | |
396 | if (scm_is_null (CDR (forms))) | |
397 | return expand (CAR (forms), env); | |
398 | else | |
399 | return SEQUENCE (SCM_BOOL_F, expand_exprs (forms, env)); | |
400 | } | |
401 | ||
402 | ||
403 | \f | |
404 | ||
405 | ||
406 | static SCM | |
407 | expand_at (SCM expr, SCM env SCM_UNUSED) | |
408 | { | |
409 | ASSERT_SYNTAX (scm_ilength (expr) == 3, s_bad_expression, expr); | |
410 | ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr); | |
411 | ASSERT_SYNTAX (scm_is_symbol (CADDR (expr)), s_bad_expression, expr); | |
412 | ||
413 | return MODULE_REF (scm_source_properties (expr), | |
414 | CADR (expr), CADDR (expr), SCM_BOOL_T); | |
415 | } | |
416 | ||
417 | static SCM | |
418 | expand_atat (SCM expr, SCM env SCM_UNUSED) | |
419 | { | |
420 | ASSERT_SYNTAX (scm_ilength (expr) == 3, s_bad_expression, expr); | |
421 | ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr); | |
422 | ASSERT_SYNTAX (scm_is_symbol (CADDR (expr)), s_bad_expression, expr); | |
423 | ||
424 | return MODULE_REF (scm_source_properties (expr), | |
425 | CADR (expr), CADDR (expr), SCM_BOOL_F); | |
426 | } | |
427 | ||
428 | static SCM | |
429 | expand_and (SCM expr, SCM env) | |
430 | { | |
431 | const SCM cdr_expr = CDR (expr); | |
432 | ||
433 | if (scm_is_null (cdr_expr)) | |
434 | return CONST (SCM_BOOL_F, SCM_BOOL_T); | |
435 | ||
436 | ASSERT_SYNTAX (scm_is_pair (cdr_expr), s_bad_expression, expr); | |
437 | ||
438 | if (scm_is_null (CDR (cdr_expr))) | |
439 | return expand (CAR (cdr_expr), env); | |
440 | else | |
441 | return CONDITIONAL (scm_source_properties (expr), | |
442 | expand (CAR (cdr_expr), env), | |
443 | expand_and (cdr_expr, env), | |
444 | CONST (SCM_BOOL_F, SCM_BOOL_F)); | |
445 | } | |
446 | ||
447 | static SCM | |
448 | expand_begin (SCM expr, SCM env) | |
449 | { | |
450 | const SCM cdr_expr = CDR (expr); | |
451 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 1, s_bad_expression, expr); | |
452 | return expand_sequence (cdr_expr, env); | |
453 | } | |
454 | ||
455 | static SCM | |
456 | expand_cond_clauses (SCM clause, SCM rest, int elp, int alp, SCM env) | |
457 | { | |
458 | SCM test; | |
459 | const long length = scm_ilength (clause); | |
460 | ASSERT_SYNTAX (length >= 1, s_bad_cond_clause, clause); | |
461 | ||
462 | test = CAR (clause); | |
463 | if (scm_is_eq (test, scm_sym_else) && elp) | |
464 | { | |
465 | const int last_clause_p = scm_is_null (rest); | |
466 | ASSERT_SYNTAX (length >= 2, s_bad_cond_clause, clause); | |
467 | ASSERT_SYNTAX (last_clause_p, s_misplaced_else_clause, clause); | |
468 | return expand_sequence (CDR (clause), env); | |
469 | } | |
470 | ||
471 | if (scm_is_null (rest)) | |
472 | rest = VOID (SCM_BOOL_F); | |
473 | else | |
474 | rest = expand_cond_clauses (CAR (rest), CDR (rest), elp, alp, env); | |
475 | ||
476 | if (length >= 2 | |
477 | && scm_is_eq (CADR (clause), scm_sym_arrow) | |
478 | && alp) | |
479 | { | |
480 | SCM tmp = scm_gensym (scm_from_locale_string ("cond ")); | |
481 | SCM new_env = scm_acons (tmp, tmp, env); | |
482 | ASSERT_SYNTAX (length > 2, s_missing_recipient, clause); | |
483 | ASSERT_SYNTAX (length == 3, s_extra_expression, clause); | |
484 | return LET (SCM_BOOL_F, | |
485 | scm_list_1 (tmp), | |
486 | scm_list_1 (tmp), | |
487 | scm_list_1 (expand (test, env)), | |
488 | CONDITIONAL (SCM_BOOL_F, | |
489 | LEXICAL_REF (SCM_BOOL_F, tmp, tmp), | |
490 | APPLICATION (SCM_BOOL_F, | |
491 | expand (CADDR (clause), new_env), | |
492 | scm_list_1 (LEXICAL_REF (SCM_BOOL_F, | |
493 | tmp, tmp))), | |
494 | rest)); | |
495 | } | |
496 | /* FIXME length == 1 case */ | |
497 | else | |
498 | return CONDITIONAL (SCM_BOOL_F, | |
499 | expand (test, env), | |
500 | expand_sequence (CDR (clause), env), | |
501 | rest); | |
502 | } | |
503 | ||
504 | static SCM | |
505 | expand_cond (SCM expr, SCM env) | |
506 | { | |
507 | const int else_literal_p = expand_env_var_is_free (env, scm_sym_else); | |
508 | const int arrow_literal_p = expand_env_var_is_free (env, scm_sym_arrow); | |
509 | const SCM clauses = CDR (expr); | |
510 | ||
511 | ASSERT_SYNTAX (scm_ilength (clauses) >= 0, s_bad_expression, expr); | |
512 | ASSERT_SYNTAX (scm_ilength (clauses) >= 1, s_missing_clauses, expr); | |
513 | ||
514 | return expand_cond_clauses (CAR (clauses), CDR (clauses), | |
515 | else_literal_p, arrow_literal_p, env); | |
516 | } | |
517 | ||
518 | /* lone forward decl */ | |
519 | static SCM expand_lambda (SCM expr, SCM env); | |
520 | ||
521 | /* According to Section 5.2.1 of R5RS we first have to make sure that the | |
522 | variable is bound, and then perform the `(set! variable expression)' | |
523 | operation. However, EXPRESSION _can_ be evaluated before VARIABLE is | |
524 | bound. This means that EXPRESSION won't necessarily be able to assign | |
525 | values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'. */ | |
526 | static SCM | |
527 | expand_define (SCM expr, SCM env) | |
528 | { | |
529 | const SCM cdr_expr = CDR (expr); | |
530 | SCM body; | |
531 | SCM variable; | |
532 | ||
533 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr); | |
534 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 2, s_missing_expression, expr); | |
535 | ASSERT_SYNTAX (!scm_is_pair (env), s_bad_define, expr); | |
536 | ||
537 | body = CDR (cdr_expr); | |
538 | variable = CAR (cdr_expr); | |
539 | ||
540 | if (scm_is_pair (variable)) | |
541 | { | |
542 | ASSERT_SYNTAX_2 (scm_is_symbol (CAR (variable)), s_bad_variable, variable, expr); | |
543 | return TOPLEVEL_DEFINE | |
544 | (scm_source_properties (expr), | |
545 | CAR (variable), | |
546 | expand_lambda (scm_cons (scm_sym_lambda, scm_cons (CDR (variable), body)), | |
547 | env)); | |
548 | } | |
549 | ASSERT_SYNTAX_2 (scm_is_symbol (variable), s_bad_variable, variable, expr); | |
550 | ASSERT_SYNTAX (scm_ilength (body) == 1, s_expression, expr); | |
551 | return TOPLEVEL_DEFINE (scm_source_properties (expr), variable, | |
552 | expand (CAR (body), env)); | |
553 | } | |
554 | ||
555 | static SCM | |
556 | expand_with_fluids (SCM expr, SCM env) | |
557 | { | |
558 | SCM binds, fluids, vals; | |
559 | ASSERT_SYNTAX (scm_ilength (expr) >= 3, s_bad_expression, expr); | |
560 | binds = CADR (expr); | |
561 | ASSERT_SYNTAX_2 (scm_ilength (binds) >= 0, s_bad_bindings, binds, expr); | |
562 | for (fluids = SCM_EOL, vals = SCM_EOL; | |
563 | scm_is_pair (binds); | |
564 | binds = CDR (binds)) | |
565 | { | |
566 | SCM binding = CAR (binds); | |
567 | ASSERT_SYNTAX_2 (scm_ilength (CAR (binds)) == 2, s_bad_binding, | |
568 | binding, expr); | |
569 | fluids = scm_cons (expand (CAR (binding), env), fluids); | |
570 | vals = scm_cons (expand (CADR (binding), env), vals); | |
571 | } | |
572 | ||
573 | return DYNLET (scm_source_properties (expr), | |
574 | scm_reverse_x (fluids, SCM_UNDEFINED), | |
575 | scm_reverse_x (vals, SCM_UNDEFINED), | |
576 | expand_sequence (CDDR (expr), env)); | |
577 | } | |
578 | ||
579 | static SCM | |
580 | expand_eval_when (SCM expr, SCM env) | |
581 | { | |
582 | ASSERT_SYNTAX (scm_ilength (expr) >= 3, s_bad_expression, expr); | |
583 | ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr); | |
584 | ||
585 | if (scm_is_true (scm_memq (sym_eval, CADR (expr))) | |
586 | || scm_is_true (scm_memq (sym_load, CADR (expr)))) | |
587 | return expand_sequence (CDDR (expr), env); | |
588 | else | |
589 | return VOID (scm_source_properties (expr)); | |
590 | } | |
591 | ||
592 | static SCM | |
593 | expand_if (SCM expr, SCM env SCM_UNUSED) | |
594 | { | |
595 | const SCM cdr_expr = CDR (expr); | |
596 | const long length = scm_ilength (cdr_expr); | |
597 | ASSERT_SYNTAX (length == 2 || length == 3, s_expression, expr); | |
598 | return CONDITIONAL (scm_source_properties (expr), | |
599 | expand (CADR (expr), env), | |
600 | expand (CADDR (expr), env), | |
601 | ((length == 3) | |
602 | ? expand (CADDDR (expr), env) | |
603 | : VOID (SCM_BOOL_F))); | |
604 | } | |
605 | ||
606 | /* A helper function for expand_lambda to support checking for duplicate | |
607 | * formal arguments: Return true if OBJ is `eq?' to one of the elements of | |
608 | * LIST or to the CDR of the last cons. Therefore, LIST may have any of the | |
609 | * forms that a formal argument can have: | |
610 | * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */ | |
611 | static int | |
612 | c_improper_memq (SCM obj, SCM list) | |
613 | { | |
614 | for (; scm_is_pair (list); list = CDR (list)) | |
615 | { | |
616 | if (scm_is_eq (CAR (list), obj)) | |
617 | return 1; | |
618 | } | |
619 | return scm_is_eq (list, obj); | |
620 | } | |
621 | ||
622 | static SCM | |
623 | expand_lambda_case (SCM clause, SCM alternate, SCM env) | |
624 | { | |
625 | SCM formals; | |
626 | SCM rest; | |
627 | SCM req = SCM_EOL; | |
628 | SCM vars = SCM_EOL; | |
629 | SCM body; | |
630 | int nreq = 0; | |
631 | ||
632 | ASSERT_SYNTAX (scm_is_pair (clause) && scm_is_pair (CDR (clause)), | |
633 | s_bad_expression, scm_cons (scm_sym_lambda, clause)); | |
634 | ||
635 | /* Before iterating the list of formal arguments, make sure the formals | |
636 | * actually are given as either a symbol or a non-cyclic list. */ | |
637 | formals = CAR (clause); | |
638 | if (scm_is_pair (formals)) | |
639 | { | |
640 | /* Dirk:FIXME:: We should check for a cyclic list of formals, and if | |
641 | * detected, report a 'Bad formals' error. */ | |
642 | } | |
643 | else | |
644 | ASSERT_SYNTAX_2 (scm_is_symbol (formals) || scm_is_null (formals), | |
645 | s_bad_formals, formals, scm_cons (scm_sym_lambda, clause)); | |
646 | ||
647 | /* Now iterate the list of formal arguments to check if all formals are | |
648 | * symbols, and that there are no duplicates. */ | |
649 | while (scm_is_pair (formals)) | |
650 | { | |
651 | const SCM formal = CAR (formals); | |
652 | formals = CDR (formals); | |
653 | ASSERT_SYNTAX_2 (scm_is_symbol (formal), s_bad_formal, formal, | |
654 | scm_cons (scm_sym_lambda, clause)); | |
655 | ASSERT_SYNTAX_2 (!c_improper_memq (formal, formals), s_duplicate_formal, | |
656 | formal, scm_cons (scm_sym_lambda, clause)); | |
657 | nreq++; | |
658 | req = scm_cons (formal, req); | |
659 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
660 | env = scm_acons (formal, CAR (vars), env); | |
661 | } | |
662 | ||
663 | ASSERT_SYNTAX_2 (scm_is_null (formals) || scm_is_symbol (formals), | |
664 | s_bad_formal, formals, scm_cons (scm_sym_lambda, clause)); | |
665 | if (scm_is_symbol (formals)) | |
666 | { | |
667 | rest = formals; | |
668 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
669 | env = scm_acons (rest, CAR (vars), env); | |
670 | } | |
671 | else | |
672 | rest = SCM_BOOL_F; | |
673 | ||
674 | body = expand_sequence (CDR (clause), env); | |
675 | req = scm_reverse_x (req, SCM_UNDEFINED); | |
676 | vars = scm_reverse_x (vars, SCM_UNDEFINED); | |
677 | ||
678 | if (scm_is_true (alternate) && !(SCM_EXPANDED_P (alternate) && SCM_EXPANDED_TYPE (alternate) == SCM_EXPANDED_LAMBDA_CASE)) | |
679 | abort (); | |
680 | ||
681 | return LAMBDA_CASE (SCM_BOOL_F, req, SCM_BOOL_F, rest, SCM_BOOL_F, | |
682 | SCM_EOL, vars, body, alternate); | |
683 | } | |
684 | ||
685 | static SCM | |
686 | expand_lambda (SCM expr, SCM env) | |
687 | { | |
688 | return LAMBDA (scm_source_properties (expr), | |
689 | SCM_EOL, | |
690 | expand_lambda_case (CDR (expr), SCM_BOOL_F, env)); | |
691 | } | |
692 | ||
693 | static SCM | |
694 | expand_lambda_star_case (SCM clause, SCM alternate, SCM env) | |
695 | { | |
696 | SCM req, opt, kw, allow_other_keys, rest, formals, vars, body, tmp; | |
632ddbf0 | 697 | SCM inits; |
dc3e203e AW |
698 | int nreq, nopt; |
699 | ||
700 | const long length = scm_ilength (clause); | |
701 | ASSERT_SYNTAX (length >= 1, s_bad_expression, | |
702 | scm_cons (sym_lambda_star, clause)); | |
703 | ASSERT_SYNTAX (length >= 2, s_missing_expression, | |
704 | scm_cons (sym_lambda_star, clause)); | |
705 | ||
706 | formals = CAR (clause); | |
707 | body = CDR (clause); | |
708 | ||
709 | nreq = nopt = 0; | |
710 | req = opt = kw = SCM_EOL; | |
711 | rest = allow_other_keys = SCM_BOOL_F; | |
712 | ||
713 | while (scm_is_pair (formals) && scm_is_symbol (CAR (formals))) | |
714 | { | |
715 | nreq++; | |
716 | req = scm_cons (CAR (formals), req); | |
717 | formals = scm_cdr (formals); | |
718 | } | |
719 | ||
720 | if (scm_is_pair (formals) && scm_is_eq (CAR (formals), kw_optional)) | |
721 | { | |
722 | formals = CDR (formals); | |
723 | while (scm_is_pair (formals) | |
724 | && (scm_is_symbol (CAR (formals)) || scm_is_pair (CAR (formals)))) | |
725 | { | |
726 | nopt++; | |
727 | opt = scm_cons (CAR (formals), opt); | |
728 | formals = scm_cdr (formals); | |
729 | } | |
730 | } | |
731 | ||
732 | if (scm_is_pair (formals) && scm_is_eq (CAR (formals), kw_key)) | |
733 | { | |
734 | formals = CDR (formals); | |
735 | while (scm_is_pair (formals) | |
736 | && (scm_is_symbol (CAR (formals)) || scm_is_pair (CAR (formals)))) | |
737 | { | |
738 | kw = scm_cons (CAR (formals), kw); | |
739 | formals = scm_cdr (formals); | |
740 | } | |
741 | } | |
742 | ||
743 | if (scm_is_pair (formals) && scm_is_eq (CAR (formals), kw_allow_other_keys)) | |
744 | { | |
745 | formals = CDR (formals); | |
746 | allow_other_keys = SCM_BOOL_T; | |
747 | } | |
748 | ||
749 | if (scm_is_pair (formals) && scm_is_eq (CAR (formals), kw_rest)) | |
750 | { | |
751 | ASSERT_SYNTAX (scm_ilength (formals) == 2, s_bad_formals, | |
752 | CAR (clause)); | |
753 | rest = CADR (formals); | |
754 | } | |
755 | else if (scm_is_symbol (formals)) | |
756 | rest = formals; | |
757 | else | |
758 | { | |
759 | ASSERT_SYNTAX (scm_is_null (formals), s_bad_formals, CAR (clause)); | |
760 | rest = SCM_BOOL_F; | |
761 | } | |
762 | ||
763 | /* Now, iterate through them a second time, building up an expansion-time | |
764 | environment, checking, expanding and canonicalizing the opt/kw init forms, | |
765 | and eventually memoizing the body as well. Note that the rest argument, if | |
766 | any, is expanded before keyword args, thus necessitating the second | |
767 | pass. | |
768 | ||
769 | Also note that the specific environment during expansion of init | |
770 | expressions here needs to coincide with the environment when psyntax | |
771 | expands. A lot of effort for something that is only used in the bootstrap | |
772 | expandr, you say? Yes. Yes it is. | |
773 | */ | |
774 | ||
775 | vars = SCM_EOL; | |
776 | req = scm_reverse_x (req, SCM_EOL); | |
777 | for (tmp = req; scm_is_pair (tmp); tmp = scm_cdr (tmp)) | |
778 | { | |
779 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
780 | env = scm_acons (CAR (tmp), CAR (vars), env); | |
781 | } | |
782 | ||
783 | /* Build up opt inits and env */ | |
784 | inits = SCM_EOL; | |
785 | opt = scm_reverse_x (opt, SCM_EOL); | |
786 | for (tmp = opt; scm_is_pair (tmp); tmp = scm_cdr (tmp)) | |
787 | { | |
788 | SCM x = CAR (tmp); | |
789 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
790 | env = scm_acons (x, CAR (vars), env); | |
791 | if (scm_is_symbol (x)) | |
792 | inits = scm_cons (CONST (SCM_BOOL_F, SCM_BOOL_F), inits); | |
793 | else | |
794 | { | |
795 | ASSERT_SYNTAX (scm_ilength (x) == 2 && scm_is_symbol (CAR (x)), | |
796 | s_bad_formals, CAR (clause)); | |
797 | inits = scm_cons (expand (CADR (x), env), inits); | |
798 | } | |
799 | env = scm_acons (scm_is_symbol (x) ? x : CAR (x), CAR (vars), env); | |
800 | } | |
801 | if (scm_is_null (opt)) | |
802 | opt = SCM_BOOL_F; | |
803 | ||
804 | /* Process rest before keyword args */ | |
805 | if (scm_is_true (rest)) | |
806 | { | |
807 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
808 | env = scm_acons (rest, CAR (vars), env); | |
809 | } | |
810 | ||
632ddbf0 | 811 | /* Build up kw inits, env, and kw-canon list */ |
dc3e203e AW |
812 | if (scm_is_null (kw)) |
813 | kw = SCM_BOOL_F; | |
814 | else | |
815 | { | |
632ddbf0 | 816 | SCM kw_canon = SCM_EOL; |
dc3e203e AW |
817 | kw = scm_reverse_x (kw, SCM_UNDEFINED); |
818 | for (tmp = kw; scm_is_pair (tmp); tmp = scm_cdr (tmp)) | |
819 | { | |
820 | SCM x, sym, k, init; | |
821 | x = CAR (tmp); | |
822 | if (scm_is_symbol (x)) | |
823 | { | |
824 | sym = x; | |
825 | init = SCM_BOOL_F; | |
826 | k = scm_symbol_to_keyword (sym); | |
827 | } | |
828 | else if (scm_ilength (x) == 2 && scm_is_symbol (CAR (x))) | |
829 | { | |
830 | sym = CAR (x); | |
831 | init = CADR (x); | |
832 | k = scm_symbol_to_keyword (sym); | |
833 | } | |
834 | else if (scm_ilength (x) == 3 && scm_is_symbol (CAR (x)) | |
835 | && scm_is_keyword (CADDR (x))) | |
836 | { | |
837 | sym = CAR (x); | |
838 | init = CADR (x); | |
839 | k = CADDR (x); | |
840 | } | |
841 | else | |
842 | syntax_error (s_bad_formals, CAR (clause), SCM_UNDEFINED); | |
843 | ||
dc3e203e AW |
844 | inits = scm_cons (expand (init, env), inits); |
845 | vars = scm_cons (scm_gensym (SCM_UNDEFINED), vars); | |
632ddbf0 | 846 | kw_canon = scm_cons (scm_list_3 (k, sym, CAR (vars)), kw_canon); |
dc3e203e AW |
847 | env = scm_acons (sym, CAR (vars), env); |
848 | } | |
632ddbf0 AW |
849 | kw_canon = scm_reverse_x (kw_canon, SCM_UNDEFINED); |
850 | kw = scm_cons (allow_other_keys, kw_canon); | |
dc3e203e AW |
851 | } |
852 | ||
853 | /* We should check for no duplicates, but given that psyntax does this | |
854 | already, we can punt on it here... */ | |
855 | ||
856 | vars = scm_reverse_x (vars, SCM_UNDEFINED); | |
857 | inits = scm_reverse_x (inits, SCM_UNDEFINED); | |
858 | body = expand_sequence (body, env); | |
859 | ||
860 | return LAMBDA_CASE (SCM_BOOL_F, req, opt, rest, kw, inits, vars, body, | |
861 | alternate); | |
862 | } | |
863 | ||
864 | static SCM | |
865 | expand_lambda_star (SCM expr, SCM env) | |
866 | { | |
867 | return LAMBDA (scm_source_properties (expr), | |
868 | SCM_EOL, | |
869 | expand_lambda_star_case (CDR (expr), SCM_BOOL_F, env)); | |
870 | } | |
871 | ||
872 | static SCM | |
873 | expand_case_lambda_clauses (SCM expr, SCM rest, SCM env) | |
874 | { | |
875 | SCM alt; | |
876 | ||
877 | if (scm_is_pair (rest)) | |
878 | alt = expand_case_lambda_clauses (CAR (rest), CDR (rest), env); | |
879 | else | |
880 | alt = SCM_BOOL_F; | |
881 | ||
882 | return expand_lambda_case (expr, alt, env); | |
883 | } | |
884 | ||
885 | static SCM | |
886 | expand_case_lambda (SCM expr, SCM env) | |
887 | { | |
888 | ASSERT_SYNTAX (scm_is_pair (CDR (expr)), s_missing_expression, expr); | |
889 | ||
890 | return LAMBDA (scm_source_properties (expr), | |
891 | SCM_EOL, | |
892 | expand_case_lambda_clauses (CADR (expr), CDDR (expr), env)); | |
893 | } | |
894 | ||
895 | static SCM | |
896 | expand_case_lambda_star_clauses (SCM expr, SCM rest, SCM env) | |
897 | { | |
898 | SCM alt; | |
899 | ||
900 | if (scm_is_pair (rest)) | |
901 | alt = expand_case_lambda_star_clauses (CAR (rest), CDR (rest), env); | |
902 | else | |
903 | alt = SCM_BOOL_F; | |
904 | ||
905 | return expand_lambda_star_case (expr, alt, env); | |
906 | } | |
907 | ||
908 | static SCM | |
909 | expand_case_lambda_star (SCM expr, SCM env) | |
910 | { | |
911 | ASSERT_SYNTAX (scm_is_pair (CDR (expr)), s_missing_expression, expr); | |
912 | ||
913 | return LAMBDA (scm_source_properties (expr), | |
914 | SCM_EOL, | |
915 | expand_case_lambda_star_clauses (CADR (expr), CDDR (expr), env)); | |
916 | } | |
917 | ||
918 | /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */ | |
919 | static void | |
920 | check_bindings (const SCM bindings, const SCM expr) | |
921 | { | |
922 | SCM binding_idx; | |
923 | ||
924 | ASSERT_SYNTAX_2 (scm_ilength (bindings) >= 0, | |
925 | s_bad_bindings, bindings, expr); | |
926 | ||
927 | binding_idx = bindings; | |
928 | for (; !scm_is_null (binding_idx); binding_idx = CDR (binding_idx)) | |
929 | { | |
930 | SCM name; /* const */ | |
931 | ||
932 | const SCM binding = CAR (binding_idx); | |
933 | ASSERT_SYNTAX_2 (scm_ilength (binding) == 2, | |
934 | s_bad_binding, binding, expr); | |
935 | ||
936 | name = CAR (binding); | |
937 | ASSERT_SYNTAX_2 (scm_is_symbol (name), s_bad_variable, name, expr); | |
938 | } | |
939 | } | |
940 | ||
941 | /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are | |
942 | * transformed to the lists (vn .. v2 v1) and (i1 i2 ... in). If a duplicate | |
943 | * variable name is detected, an error is signalled. */ | |
944 | static void | |
945 | transform_bindings (const SCM bindings, const SCM expr, | |
946 | SCM *const names, SCM *const vars, SCM *const initptr) | |
947 | { | |
948 | SCM rnames = SCM_EOL; | |
949 | SCM rvars = SCM_EOL; | |
950 | SCM rinits = SCM_EOL; | |
951 | SCM binding_idx = bindings; | |
952 | for (; !scm_is_null (binding_idx); binding_idx = CDR (binding_idx)) | |
953 | { | |
954 | const SCM binding = CAR (binding_idx); | |
955 | const SCM CDR_binding = CDR (binding); | |
956 | const SCM name = CAR (binding); | |
957 | ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name, rnames)), | |
958 | s_duplicate_binding, name, expr); | |
959 | rnames = scm_cons (name, rnames); | |
960 | rvars = scm_cons (scm_gensym (SCM_UNDEFINED), rvars); | |
961 | rinits = scm_cons (CAR (CDR_binding), rinits); | |
962 | } | |
963 | *names = scm_reverse_x (rnames, SCM_UNDEFINED); | |
964 | *vars = scm_reverse_x (rvars, SCM_UNDEFINED); | |
965 | *initptr = scm_reverse_x (rinits, SCM_UNDEFINED); | |
966 | } | |
967 | ||
968 | /* FIXME: Remove named let in this boot expander. */ | |
969 | static SCM | |
970 | expand_named_let (const SCM expr, SCM env) | |
971 | { | |
972 | SCM var_names, var_syms, inits; | |
973 | SCM inner_env; | |
974 | SCM name_sym; | |
975 | ||
976 | const SCM cdr_expr = CDR (expr); | |
977 | const SCM name = CAR (cdr_expr); | |
978 | const SCM cddr_expr = CDR (cdr_expr); | |
979 | const SCM bindings = CAR (cddr_expr); | |
980 | check_bindings (bindings, expr); | |
981 | ||
982 | transform_bindings (bindings, expr, &var_names, &var_syms, &inits); | |
983 | name_sym = scm_gensym (SCM_UNDEFINED); | |
984 | inner_env = scm_acons (name, name_sym, env); | |
985 | inner_env = expand_env_extend (inner_env, var_names, var_syms); | |
986 | ||
987 | return LETREC | |
fb6e61ca | 988 | (scm_source_properties (expr), SCM_BOOL_F, |
dc3e203e AW |
989 | scm_list_1 (name), scm_list_1 (name_sym), |
990 | scm_list_1 (LAMBDA (SCM_BOOL_F, | |
991 | SCM_EOL, | |
992 | LAMBDA_CASE (SCM_BOOL_F, var_names, SCM_BOOL_F, SCM_BOOL_F, | |
993 | SCM_BOOL_F, SCM_BOOL_F, var_syms, | |
994 | expand_sequence (CDDDR (expr), inner_env), | |
995 | SCM_BOOL_F))), | |
996 | APPLICATION (SCM_BOOL_F, | |
997 | LEXICAL_REF (SCM_BOOL_F, name, name_sym), | |
998 | expand_exprs (inits, env))); | |
999 | } | |
1000 | ||
1001 | static SCM | |
1002 | expand_let (SCM expr, SCM env) | |
1003 | { | |
1004 | SCM bindings; | |
1005 | ||
1006 | const SCM cdr_expr = CDR (expr); | |
1007 | const long length = scm_ilength (cdr_expr); | |
1008 | ASSERT_SYNTAX (length >= 0, s_bad_expression, expr); | |
1009 | ASSERT_SYNTAX (length >= 2, s_missing_expression, expr); | |
1010 | ||
1011 | bindings = CAR (cdr_expr); | |
1012 | if (scm_is_symbol (bindings)) | |
1013 | { | |
1014 | ASSERT_SYNTAX (length >= 3, s_missing_expression, expr); | |
1015 | return expand_named_let (expr, env); | |
1016 | } | |
1017 | ||
1018 | check_bindings (bindings, expr); | |
1019 | if (scm_is_null (bindings)) | |
1020 | return expand_sequence (CDDR (expr), env); | |
1021 | else | |
1022 | { | |
1023 | SCM var_names, var_syms, inits; | |
1024 | transform_bindings (bindings, expr, &var_names, &var_syms, &inits); | |
1025 | return LET (SCM_BOOL_F, | |
1026 | var_names, var_syms, expand_exprs (inits, env), | |
1027 | expand_sequence (CDDR (expr), | |
1028 | expand_env_extend (env, var_names, | |
1029 | var_syms))); | |
1030 | } | |
1031 | } | |
1032 | ||
1033 | static SCM | |
826373a2 | 1034 | expand_letrec_helper (SCM expr, SCM env, SCM in_order_p) |
dc3e203e AW |
1035 | { |
1036 | SCM bindings; | |
1037 | ||
1038 | const SCM cdr_expr = CDR (expr); | |
1039 | const long length = scm_ilength (cdr_expr); | |
1040 | ASSERT_SYNTAX (length >= 0, s_bad_expression, expr); | |
1041 | ASSERT_SYNTAX (length >= 2, s_missing_expression, expr); | |
1042 | ||
1043 | bindings = CAR (cdr_expr); | |
1044 | check_bindings (bindings, expr); | |
1045 | if (scm_is_null (bindings)) | |
1046 | return expand_sequence (CDDR (expr), env); | |
1047 | else | |
1048 | { | |
1049 | SCM var_names, var_syms, inits; | |
1050 | transform_bindings (bindings, expr, &var_names, &var_syms, &inits); | |
1051 | env = expand_env_extend (env, var_names, var_syms); | |
826373a2 | 1052 | return LETREC (SCM_BOOL_F, in_order_p, |
dc3e203e AW |
1053 | var_names, var_syms, expand_exprs (inits, env), |
1054 | expand_sequence (CDDR (expr), env)); | |
1055 | } | |
1056 | } | |
1057 | ||
826373a2 AW |
1058 | static SCM |
1059 | expand_letrec (SCM expr, SCM env) | |
1060 | { | |
1061 | return expand_letrec_helper (expr, env, SCM_BOOL_F); | |
1062 | } | |
1063 | ||
1064 | static SCM | |
1065 | expand_letrec_star (SCM expr, SCM env) | |
1066 | { | |
1067 | return expand_letrec_helper (expr, env, SCM_BOOL_T); | |
1068 | } | |
1069 | ||
dc3e203e AW |
1070 | static SCM |
1071 | expand_letstar_clause (SCM bindings, SCM body, SCM env SCM_UNUSED) | |
1072 | { | |
1073 | if (scm_is_null (bindings)) | |
1074 | return expand_sequence (body, env); | |
1075 | else | |
1076 | { | |
1077 | SCM bind, name, sym, init; | |
1078 | ||
1079 | ASSERT_SYNTAX (scm_is_pair (bindings), s_bad_expression, bindings); | |
1080 | bind = CAR (bindings); | |
1081 | ASSERT_SYNTAX (scm_ilength (bind) == 2, s_bad_binding, bind); | |
1082 | name = CAR (bind); | |
1083 | sym = scm_gensym (SCM_UNDEFINED); | |
1084 | init = CADR (bind); | |
1085 | ||
1086 | return LET (SCM_BOOL_F, scm_list_1 (name), scm_list_1 (sym), | |
1087 | scm_list_1 (expand (init, env)), | |
1088 | expand_letstar_clause (CDR (bindings), body, | |
1089 | scm_acons (name, sym, env))); | |
1090 | } | |
1091 | } | |
1092 | ||
1093 | static SCM | |
1094 | expand_letstar (SCM expr, SCM env SCM_UNUSED) | |
1095 | { | |
1096 | const SCM cdr_expr = CDR (expr); | |
1097 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr); | |
1098 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 2, s_missing_expression, expr); | |
1099 | ||
1100 | return expand_letstar_clause (CADR (expr), CDDR (expr), env); | |
1101 | } | |
1102 | ||
1103 | static SCM | |
1104 | expand_or (SCM expr, SCM env SCM_UNUSED) | |
1105 | { | |
1106 | SCM tail = CDR (expr); | |
1107 | const long length = scm_ilength (tail); | |
1108 | ||
1109 | ASSERT_SYNTAX (length >= 0, s_bad_expression, expr); | |
1110 | ||
1111 | if (scm_is_null (CDR (expr))) | |
1112 | return CONST (SCM_BOOL_F, SCM_BOOL_F); | |
1113 | else | |
1114 | { | |
1115 | SCM tmp = scm_gensym (SCM_UNDEFINED); | |
1116 | return LET (SCM_BOOL_F, | |
1117 | scm_list_1 (tmp), scm_list_1 (tmp), | |
1118 | scm_list_1 (expand (CADR (expr), env)), | |
1119 | CONDITIONAL (SCM_BOOL_F, | |
1120 | LEXICAL_REF (SCM_BOOL_F, tmp, tmp), | |
1121 | LEXICAL_REF (SCM_BOOL_F, tmp, tmp), | |
1122 | expand_or (CDR (expr), | |
1123 | scm_acons (tmp, tmp, env)))); | |
1124 | } | |
1125 | } | |
1126 | ||
1127 | static SCM | |
1128 | expand_quote (SCM expr, SCM env SCM_UNUSED) | |
1129 | { | |
1130 | SCM quotee; | |
1131 | ||
1132 | const SCM cdr_expr = CDR (expr); | |
1133 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr); | |
1134 | ASSERT_SYNTAX (scm_ilength (cdr_expr) == 1, s_expression, expr); | |
1135 | quotee = CAR (cdr_expr); | |
1136 | return CONST (scm_source_properties (expr), quotee); | |
1137 | } | |
1138 | ||
1139 | static SCM | |
1140 | expand_set_x (SCM expr, SCM env) | |
1141 | { | |
1142 | SCM variable; | |
1143 | SCM vmem; | |
1144 | ||
1145 | const SCM cdr_expr = CDR (expr); | |
1146 | ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr); | |
1147 | ASSERT_SYNTAX (scm_ilength (cdr_expr) == 2, s_expression, expr); | |
1148 | variable = CAR (cdr_expr); | |
1149 | vmem = expand (variable, env); | |
1150 | ||
1151 | switch (SCM_EXPANDED_TYPE (vmem)) | |
1152 | { | |
1153 | case SCM_EXPANDED_LEXICAL_REF: | |
1154 | return LEXICAL_SET (scm_source_properties (expr), | |
1155 | SCM_EXPANDED_REF (vmem, LEXICAL_REF, NAME), | |
1156 | SCM_EXPANDED_REF (vmem, LEXICAL_REF, GENSYM), | |
1157 | expand (CADDR (expr), env)); | |
1158 | case SCM_EXPANDED_TOPLEVEL_REF: | |
1159 | return TOPLEVEL_SET (scm_source_properties (expr), | |
1160 | SCM_EXPANDED_REF (vmem, TOPLEVEL_REF, NAME), | |
1161 | expand (CADDR (expr), env)); | |
1162 | case SCM_EXPANDED_MODULE_REF: | |
1163 | return MODULE_SET (scm_source_properties (expr), | |
1164 | SCM_EXPANDED_REF (vmem, MODULE_REF, MOD), | |
1165 | SCM_EXPANDED_REF (vmem, MODULE_REF, NAME), | |
1166 | SCM_EXPANDED_REF (vmem, MODULE_REF, PUBLIC), | |
1167 | expand (CADDR (expr), env)); | |
1168 | default: | |
1169 | syntax_error (s_bad_variable, variable, expr); | |
1170 | } | |
1171 | } | |
1172 | ||
1173 | ||
1174 | \f | |
1175 | ||
a310a1d1 AW |
1176 | /* This is the boot expander. It is later replaced with psyntax's sc-expand. */ |
1177 | SCM_DEFINE (scm_macroexpand, "macroexpand", 1, 0, 0, | |
dc3e203e AW |
1178 | (SCM exp), |
1179 | "Expand the expression @var{exp}.") | |
1180 | #define FUNC_NAME s_scm_macroexpand | |
1181 | { | |
1182 | return expand (exp, scm_current_module ()); | |
1183 | } | |
1184 | #undef FUNC_NAME | |
1185 | ||
a310a1d1 AW |
1186 | SCM_DEFINE (scm_macroexpanded_p, "macroexpanded?", 1, 0, 0, |
1187 | (SCM exp), | |
1188 | "Return @code{#t} if @var{exp} is an expanded expression.") | |
1189 | #define FUNC_NAME s_scm_macroexpanded_p | |
1190 | { | |
1191 | return scm_from_bool (SCM_EXPANDED_P (exp)); | |
1192 | } | |
1193 | #undef FUNC_NAME | |
1194 | ||
dc3e203e AW |
1195 | |
1196 | \f | |
1197 | ||
1198 | #define DEFINE_NAMES(type) \ | |
1199 | { \ | |
1200 | static const char *fields[] = SCM_EXPANDED_##type##_FIELD_NAMES; \ | |
1201 | exp_field_names[SCM_EXPANDED_##type] = fields; \ | |
1202 | exp_names[SCM_EXPANDED_##type] = SCM_EXPANDED_##type##_TYPE_NAME; \ | |
1203 | exp_nfields[SCM_EXPANDED_##type] = SCM_NUM_EXPANDED_##type##_FIELDS; \ | |
1204 | } | |
1205 | ||
1206 | static SCM | |
1207 | make_exp_vtable (size_t n) | |
1208 | { | |
1209 | SCM layout, printer, name, code, fields; | |
1210 | ||
1211 | layout = scm_string_to_symbol | |
1212 | (scm_string_append (scm_make_list (scm_from_size_t (exp_nfields[n]), | |
1213 | scm_from_locale_string ("pw")))); | |
1214 | printer = SCM_BOOL_F; | |
1215 | name = scm_from_locale_symbol (exp_names[n]); | |
1216 | code = scm_from_size_t (n); | |
1217 | fields = SCM_EOL; | |
1218 | { | |
1219 | size_t m = exp_nfields[n]; | |
1220 | while (m--) | |
1221 | fields = scm_cons (scm_from_locale_symbol (exp_field_names[n][m]), fields); | |
1222 | } | |
1223 | ||
1224 | return scm_c_make_struct (scm_exp_vtable_vtable, 0, 5, | |
1225 | SCM_UNPACK (layout), SCM_UNPACK (printer), SCM_UNPACK (name), | |
1226 | SCM_UNPACK (code), SCM_UNPACK (fields)); | |
1227 | } | |
1228 | ||
1229 | void | |
1230 | scm_init_expand () | |
1231 | { | |
1232 | size_t n; | |
1233 | SCM exp_vtable_list = SCM_EOL; | |
1234 | ||
1235 | DEFINE_NAMES (VOID); | |
1236 | DEFINE_NAMES (CONST); | |
1237 | DEFINE_NAMES (PRIMITIVE_REF); | |
1238 | DEFINE_NAMES (LEXICAL_REF); | |
1239 | DEFINE_NAMES (LEXICAL_SET); | |
1240 | DEFINE_NAMES (MODULE_REF); | |
1241 | DEFINE_NAMES (MODULE_SET); | |
1242 | DEFINE_NAMES (TOPLEVEL_REF); | |
1243 | DEFINE_NAMES (TOPLEVEL_SET); | |
1244 | DEFINE_NAMES (TOPLEVEL_DEFINE); | |
1245 | DEFINE_NAMES (CONDITIONAL); | |
1246 | DEFINE_NAMES (APPLICATION); | |
1247 | DEFINE_NAMES (SEQUENCE); | |
1248 | DEFINE_NAMES (LAMBDA); | |
1249 | DEFINE_NAMES (LAMBDA_CASE); | |
1250 | DEFINE_NAMES (LET); | |
1251 | DEFINE_NAMES (LETREC); | |
1252 | DEFINE_NAMES (DYNLET); | |
1253 | ||
1254 | scm_exp_vtable_vtable = | |
1255 | scm_make_vtable (scm_from_locale_string (SCM_VTABLE_BASE_LAYOUT "pwuwpw"), | |
1256 | SCM_BOOL_F); | |
1257 | ||
1258 | for (n = 0; n < SCM_NUM_EXPANDED_TYPES; n++) | |
1259 | exp_vtables[n] = make_exp_vtable (n); | |
1260 | ||
1261 | /* Now walk back down, consing in reverse. */ | |
1262 | while (n--) | |
1263 | exp_vtable_list = scm_cons (exp_vtables[n], exp_vtable_list); | |
1264 | ||
ccbc25f3 | 1265 | scm_c_define ("%expanded-vtables", scm_vector (exp_vtable_list)); |
dc3e203e AW |
1266 | |
1267 | #include "libguile/expand.x" | |
1268 | } | |
1269 | ||
1270 | /* | |
1271 | Local Variables: | |
1272 | c-file-style: "gnu" | |
1273 | End: | |
1274 | */ |