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