2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2004, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
23 * related information and legal notices. It is expected that any future
24 * projects/authors will amend these files as needed.
28 * nstr.c: compile and execute the item selections on sectors
30 * Known contributors to this file:
33 * Markus Armbruster, 2004
41 #include "prototypes.h"
43 static char *nstr_parse_val(char *, struct valstr *);
44 static int nstr_match_ca(struct valstr *, struct castr *);
45 static int nstr_match_val(struct valstr *, int, struct castr *, int);
46 static struct valstr *nstr_resolve_sel(struct valstr *, struct castr *);
47 static struct valstr *nstr_mkselval(struct valstr *, int, struct castr *);
48 static struct valstr *nstr_resolve_id(struct valstr *, struct castr *, int);
49 static int nstr_promote(int);
53 * Compile conditions into array NP[LEN].
54 * Return number of conditions, or -1 on error.
55 * It is an error if there are more than LEN conditions.
56 * TYPE is the context type, a file type.
57 * STR is the condition string, in Empire syntax, without the leading
61 nstr_comp(struct nscstr *np, int len, int type, char *str)
63 struct castr *ca = ef_cadef(type);
68 int lft_caidx, rgt_caidx;
70 int lft_type, rgt_type;
73 for (i = 0; ; ++i, ++np) {
78 tail = nstr_parse_val(cond, &np->lft);
79 lft_caidx = nstr_match_ca(&np->lft, ca);
82 if (*tail != '<' && *tail != '=' && *tail != '>' && *tail != '#') {
84 pr("%s -- expected condition operator\n", cond);
86 pr("%s -- missing condition operator\n", cond);
93 tail = nstr_parse_val(tail, &np->rgt);
94 rgt_caidx = nstr_match_ca(&np->rgt, ca);
99 * An identifier can name a selector or, if the other operand
100 * is a selector, a value for that. The condition is
101 * ambiguous if both selector x value and value x selector are
102 * possible. Example: n<n for sectors could mean newdes<n or
105 lft_val = nstr_match_val(&np->lft, type, ca, rgt_caidx);
106 rgt_val = nstr_match_val(&np->rgt, type, ca, lft_caidx);
108 * if lft_val >= 0, then rhs names a selector and lhs names
109 * one of its values. Likewise for rgt_val.
111 if (lft_val >= 0 && rgt_val >= 0) {
112 pr("%.*s -- condition ambiguous\n", (int)(tail-cond), cond);
114 } else if (rgt_val >= 0) {
115 /* selector x value */
116 if (!nstr_resolve_sel(&np->lft, &ca[lft_caidx]))
118 nstr_mkselval(&np->rgt, rgt_val, &ca[lft_caidx]);
119 } else if (lft_val >= 0) {
120 /* value x selector */
121 nstr_mkselval(&np->lft, lft_val, &ca[rgt_caidx]);
122 if (!nstr_resolve_sel(&np->rgt, &ca[rgt_caidx]))
126 * Neither side works as selector value; any identifiers
127 * must name selectors.
129 if (!nstr_resolve_id(&np->lft, ca, lft_caidx))
131 if (!nstr_resolve_id(&np->rgt, ca, rgt_caidx))
135 /* find operator type, coerce operands */
136 lft_type = nstr_promote(np->lft.val_type);
137 rgt_type = nstr_promote(np->rgt.val_type);
138 np->optype = NSC_NOTYPE;
139 if (lft_type == NSC_TYPEID) {
140 if (!nstr_coerce_val(&np->rgt, NSC_TYPEID, str))
141 np->optype = NSC_TYPEID;
142 } else if (rgt_type == NSC_TYPEID) {
143 if (!nstr_coerce_val(&np->lft, NSC_TYPEID, str))
144 np->optype = NSC_TYPEID;
145 } else if (lft_type == NSC_STRING) {
146 if (!nstr_coerce_val(&np->rgt, NSC_STRING, str))
147 np->optype = NSC_STRING;
148 } else if (rgt_type == NSC_STRING) {
149 if (!nstr_coerce_val(&np->lft, NSC_STRING, str))
150 np->optype = NSC_STRING;
151 } else if (lft_type == NSC_DOUBLE) {
152 if (!nstr_coerce_val(&np->rgt, NSC_DOUBLE, str))
153 np->optype = NSC_DOUBLE;
154 } else if (rgt_type == NSC_DOUBLE) {
155 if (!nstr_coerce_val(&np->lft, NSC_DOUBLE, str))
156 np->optype = NSC_DOUBLE;
158 if (!nstr_coerce_val(&np->lft, NSC_LONG, str)
159 && !nstr_coerce_val(&np->rgt, NSC_LONG, str))
160 np->optype = NSC_LONG;
162 if (np->optype == NSC_NOTYPE)
165 /* another condition? */
169 pr("%s -- expected `&'\n", cond);
176 /* could just return I and let caller gripe or enlarge buffer */
177 pr("%s -- too many conditions\n", str);
184 /* Like strcmp(S1, S2), but limit length of S1 to SZ1 and of S2 to SZ2. */
186 strnncmp(char *s1, size_t sz1, char *s2, size_t sz2)
189 if (sz1 == sz2) return strncmp(s1, s2, sz2);
190 if (sz1 < sz2) return -strnncmp(s2, sz2, s1, sz1);
191 res = strncmp(s1, s2, sz2);
192 return res ? res : s1[sz2];
195 #define EVAL(op, lft, rgt) \
196 ((op) == '<' ? (lft) < (rgt) \
197 : (op) == '=' ? (lft) == (rgt) \
198 : (op) == '>' ? (lft) > (rgt) \
199 : (op) == '#' ? (lft) != (rgt) \
203 * Evaluate compiled conditions in array NP[NCOND].
204 * Return non-zero iff they are all true.
205 * PTR points to a context object of the type that was used to compile
209 nstr_exec(struct nscstr *np, int ncond, void *ptr)
211 int i, op, optype, cmp;
212 struct valstr lft, rgt;
214 for (i = 0; i < ncond; ++i) {
216 optype = np[i].optype;
217 if (np[i].lft.val_cat == NSC_NOCAT || np[i].rgt.val_cat == NSC_NOCAT)
220 nstr_exec_val(&lft, player->cnum, ptr, optype);
222 nstr_exec_val(&rgt, player->cnum, ptr, optype);
226 if (!EVAL(op, lft.val_as.lng, rgt.val_as.lng))
230 if (!EVAL(op, lft.val_as.dbl, rgt.val_as.dbl))
234 cmp = strnncmp(lft.val_as.str.base, lft.val_as.str.maxsz,
235 rgt.val_as.str.base, rgt.val_as.str.maxsz);
236 if (!EVAL(op, cmp, 0))
240 CANT_HAPPEN("bad OPTYPE");
249 * Parse a value in STR into VAL.
250 * Return a pointer to the first character after the value.
251 * Value is either evaluated (but not NSC_TYPEID) or an identifier.
254 nstr_parse_val(char *str, struct valstr *val)
261 if (str[0] == '\'') {
262 for (tail = str + 1; *tail && *tail != '\''; ++tail) ;
263 /* FIXME implement \ quoting */
264 val->val_type = NSC_STRING;
265 val->val_cat = NSC_VAL;
266 val->val_as.str.base = str + 1;
267 val->val_as.str.maxsz = tail - (str + 1);
273 l = strtol(str, &tail, 0);
274 d = strtod(str, &tail2);
276 val->val_type = NSC_DOUBLE;
277 val->val_cat = NSC_VAL;
282 val->val_type = NSC_LONG;
283 val->val_cat = NSC_VAL;
289 for (tail = str; isalnum(*tail) || *tail == '_'; ++tail) ;
290 if (tail == str) ++tail;
291 val->val_type = NSC_NOTYPE;
292 val->val_cat = NSC_ID;
293 val->val_as.str.base = str;
294 val->val_as.str.maxsz = tail - str;
299 * Match VAL in table of selector descriptors CA, return index.
300 * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
302 * A VAL that is not an identifier doesn't match anything. A null CA
303 * is considered empty.
306 nstr_match_ca(struct valstr *val, struct castr *ca)
310 if (val->val_cat != NSC_ID || val->val_as.str.maxsz >= sizeof(id))
316 memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
317 id[val->val_as.str.maxsz] = 0;
319 return stmtch(id, ca, offsetof(struct castr, ca_name),
320 sizeof(struct castr));
324 * Match VAL in a selector's values, return its (non-negative) value.
325 * TYPE is the context type, a file type.
326 * CA is ef_cadef(TYPE).
327 * Match values of selector descriptor CA[IDX], provided CA is not
328 * null and IDX is not negative.
329 * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
331 * TODO: This is just a stub and works only for NSC_TYPEID.
332 * Generalize: give struct castr enough info to find values, remove
336 nstr_match_val(struct valstr *val, int type, struct castr *ca, int idx)
340 if (val->val_cat != NSC_ID || val->val_as.str.maxsz >= sizeof(id))
343 if (idx < 0 || ca[idx].ca_type != NSC_TYPEID)
346 memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
347 id[val->val_as.str.maxsz] = 0;
349 return typematch(id, type);
353 * Change VAL to resolve identifier to selector or string.
354 * Return VAL on success, NULL on error.
355 * No change if VAL is not an identifier.
356 * Else error if IDX == M_NOTUNIQUE, string if IDX == M_NOTFOUND, and
357 * selector CA[IDX] otherwise.
359 static struct valstr *
360 nstr_resolve_id(struct valstr *val, struct castr *ca, int idx)
362 if (val->val_cat != NSC_ID)
365 if (idx == M_NOTUNIQUE) {
366 pr("%.*s -- ambiguous name\n",
367 (int)val->val_as.str.maxsz, val->val_as.str.base);
368 val->val_cat = NSC_NOCAT;
372 if (idx == M_NOTFOUND) {
373 /* interpret unbound identifier as string */
374 val->val_type = NSC_STRING;
375 val->val_cat = NSC_VAL;
379 return nstr_resolve_sel(val, &ca[idx]);
383 * Change VAL to resolve identifier to selector CA.
384 * Return VAL on success, NULL if the player is denied access to the
386 * VAL must be an identifier.
388 static struct valstr *
389 nstr_resolve_sel(struct valstr *val, struct castr *ca)
391 if (CANT_HAPPEN(val->val_cat != NSC_ID)) {
392 val->val_cat = NSC_NOCAT;
396 if ((ca->ca_flags & NSC_DEITY) && !player->god) {
397 pr("%.*s -- not accessible to mortals\n",
398 (int)val->val_as.str.maxsz, val->val_as.str.base);
399 val->val_cat = NSC_NOCAT;
403 val->val_type = ca->ca_type;
404 val->val_cat = NSC_OFF;
405 val->val_as.sym.off = ca->ca_off;
406 val->val_as.sym.len = ca->ca_len;
407 val->val_as.sym.idx = 0;
412 * Initialize VAL to value SELVAL for selector CA, return VAL.
414 static struct valstr *
415 nstr_mkselval(struct valstr *val, int selval, struct castr *ca)
417 if (CANT_HAPPEN(ca->ca_type != NSC_TYPEID)) {
418 val->val_type = NSC_NOTYPE;
419 val->val_cat = NSC_NOCAT;
423 val->val_type = ca->ca_type;
424 val->val_cat = NSC_VAL;
425 val->val_as.lng = selval;
430 * Compile a value in STR into VAL.
431 * Return a pointer to the first character after the value on success,
433 * TYPE is the context type, a file type.
434 * If STR names an array, VAL simply refers to the element with index
438 nstr_comp_val(char *str, struct valstr *val, int type)
440 struct castr *ca = ef_cadef(type);
441 char *tail = nstr_parse_val(str, val);
442 return nstr_resolve_id(val, ca, nstr_match_ca(val, ca)) ? tail : NULL;
448 * If VALTYPE is an integer type, return NSC_LONG.
449 * If VALTYPE is a floating-point type, return NSC_DOUBLE.
450 * If VALTYPE is NSC_STRINGY, return NSC_STRING.
451 * If VALTYPE is NSC_NOTYPE, NSC_STRING or NSC_TYPEID, return VALTYPE.
454 nstr_promote(int valtype)
474 valtype = NSC_DOUBLE;
477 valtype = NSC_STRING;
480 CANT_HAPPEN("bad VALTYPE");
481 valtype = NSC_NOTYPE;
487 cond_type_mismatch(char *str)
490 pr("%s -- condition operand type mismatch\n", str);
495 * Coerce VAL to promoted value type TO.
496 * Return 0 on success, -1 on error.
497 * If VAL is evaluated, convert it, else only check.
498 * STR is the condition text to be used for error messages. Suppress
499 * messages if it is a null pointer.
502 nstr_coerce_val(struct valstr *val, nsc_type to, char *str)
504 /* FIXME get rid of promotion? */
505 nsc_type from = nstr_promote(val->val_type);
507 if (from == NSC_NOTYPE)
513 return cond_type_mismatch(str);
515 return cond_type_mismatch(str); /* FIXME implement */
517 if (from == NSC_LONG) {
518 if (val->val_cat == NSC_VAL)
519 val->val_as.dbl = val->val_as.lng;
521 return cond_type_mismatch(str);
524 return cond_type_mismatch(str);
526 CANT_HAPPEN("bad TO argument");
531 if (val->val_cat == NSC_VAL) {
532 /* coord literals don't occur, conversion not implemented */
533 CANT_HAPPEN(val->val_type == NSC_XCOORD
534 || val->val_type == NSC_YCOORD);
543 * If VAL is symbolic, evaluate it into a promoted value type.
544 * Use coordinate system of country CNUM.
545 * PTR points to a context object of the type that was used to compile
547 * Unless WANT is NSC_NOTYPE, coerce the value to promoted value type
548 * WANT. VAL must be coercible. That's the case if a previous
549 * nstr_coerce_val(VAL, WANT, STR) succeeded.
552 nstr_exec_val(struct valstr *val, natid cnum, void *ptr, nsc_type want)
558 switch (val->val_cat) {
560 CANT_HAPPEN("Bad VAL category");
563 valtype = val->val_type;
568 memb_ptr += val->val_as.sym.off;
569 idx = val->val_as.sym.idx;
570 switch (val->val_type) {
572 val->val_as.lng = ((signed char *)memb_ptr)[idx];
575 val->val_as.lng = ((unsigned char *)memb_ptr)[idx];
578 val->val_as.lng = ((short *)memb_ptr)[idx];
581 val->val_as.lng = ((unsigned short *)memb_ptr)[idx];
584 val->val_as.lng = ((int *)memb_ptr)[idx];
587 val->val_as.lng = ((long *)memb_ptr)[idx];
590 val->val_as.lng = xrel(getnatp(cnum), ((short *)memb_ptr)[idx]);
593 val->val_as.lng = yrel(getnatp(cnum), ((short *)memb_ptr)[idx]);
596 val->val_as.dbl = ((float *)memb_ptr)[idx];
597 valtype = NSC_DOUBLE;
600 val->val_as.dbl = ((double *)memb_ptr)[idx];
601 valtype = NSC_DOUBLE;
605 val->val_as.str.maxsz = val->val_as.sym.len;
606 val->val_as.str.base = (char *)memb_ptr;
607 valtype = NSC_STRING;
610 val->val_as.str.base = ((char **)memb_ptr)[idx];
611 val->val_as.str.maxsz = INT_MAX;
612 valtype = NSC_STRING;
615 val->val_as.lng = ((time_t *)memb_ptr)[idx];
618 val->val_as.lng = ((signed char *)memb_ptr)[idx];
619 valtype = NSC_TYPEID;
622 CANT_HAPPEN("Bad VAL type");
625 val->val_cat = NSC_VAL;
630 else if (want == NSC_DOUBLE) {
631 if (valtype == NSC_LONG) {
633 val->val_as.dbl = val->val_as.lng;
635 } else if (want == NSC_STRING)
636 CANT_HAPPEN("unimplemented WANT"); /* FIXME */
638 if (CANT_HAPPEN(valtype != want && want != NSC_NOTYPE)) {
642 case NSC_LONG: val->val_as.lng = 0; break;
643 case NSC_DOUBLE: val->val_as.dbl = 0.0; break;
644 case NSC_STRING: val->val_as.str.base = NULL; break;
646 CANT_HAPPEN("bad WANT argument");
650 val->val_type = valtype;