2 * Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved.
4 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
5 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
7 * Permission is hereby granted to use or copy this program
8 * for any purpose, provided the above notices are retained on all copies.
9 * Permission to modify the code and to distribute modified code is granted,
10 * provided the above notices are retained, and a notice that the code was
11 * modified is included with the above copyright notice.
13 * Author: Hans-J. Boehm (boehm@parc.xerox.com)
15 /* Boehm, October 3, 1994 5:19 pm PDT */
22 /* An implementation of the cord primitives. These are the only */
23 /* Functions that understand the representation. We perform only */
24 /* minimal checks on arguments to these functions. Out of bounds */
25 /* arguments to the iteration functions may result in client functions */
26 /* invoked on garbage data. In most cases, client functions should be */
27 /* programmed defensively enough that this does not result in memory */
30 typedef void (* oom_fn)(void);
32 oom_fn CORD_oom_fn = (oom_fn) 0;
34 # define OUT_OF_MEMORY { if (CORD_oom_fn != (oom_fn) 0) (*CORD_oom_fn)(); \
35 ABORT("Out of memory\n"); }
36 # define ABORT(msg) { fprintf(stderr, "%s\n", msg); abort(); }
38 typedef unsigned long word;
41 struct Concatenation {
44 char depth; /* concatenation nesting depth. */
45 unsigned char left_len;
46 /* Length of left child if it is sufficiently */
47 /* short; 0 otherwise. */
48 # define MAX_LEFT_LEN 255
50 CORD left; /* length(left) > 0 */
51 CORD right; /* length(right) > 0 */
56 char depth; /* always 0 */
57 char left_len; /* always 0 */
76 /* Substring nodes are a special case of function nodes. */
77 /* The client_data field is known to point to a substr_args */
78 /* structure, and the function is either CORD_apply_access_fn */
79 /* or CORD_index_access_fn. */
81 /* The following may be applied only to function and concatenation nodes: */
82 #define IS_CONCATENATION(s) (((CordRep *)s)->generic.header == CONCAT_HDR)
84 #define IS_FUNCTION(s) ((((CordRep *)s)->generic.header & FN_HDR) != 0)
86 #define IS_SUBSTR(s) (((CordRep *)s)->generic.header == SUBSTR_HDR)
88 #define LEN(s) (((CordRep *)s) -> generic.len)
89 #define DEPTH(s) (((CordRep *)s) -> generic.depth)
90 #define GEN_LEN(s) (CORD_IS_STRING(s) ? strlen(s) : LEN(s))
92 #define LEFT_LEN(c) ((c) -> left_len != 0? \
94 : (CORD_IS_STRING((c) -> left) ? \
95 (c) -> len - GEN_LEN((c) -> right) \
98 #define SHORT_LIMIT (sizeof(CordRep) - 1)
99 /* Cords shorter than this are C strings */
102 /* Dump the internal representation of x to stdout, with initial */
103 /* indentation level n. */
104 void CORD_dump_inner(CORD x, unsigned n)
108 for (i = 0; i < (size_t)n; i++) {
112 fputs("NIL\n", stdout);
113 } else if (CORD_IS_STRING(x)) {
114 for (i = 0; i <= SHORT_LIMIT; i++) {
115 if (x[i] == '\0') break;
118 if (x[i] != '\0') fputs("...", stdout);
120 } else if (IS_CONCATENATION(x)) {
121 register struct Concatenation * conc =
122 &(((CordRep *)x) -> concatenation);
123 printf("Concatenation: %p (len: %d, depth: %d)\n",
124 x, (int)(conc -> len), (int)(conc -> depth));
125 CORD_dump_inner(conc -> left, n+1);
126 CORD_dump_inner(conc -> right, n+1);
127 } else /* function */{
128 register struct Function * func =
129 &(((CordRep *)x) -> function);
130 if (IS_SUBSTR(x)) printf("(Substring) ");
131 printf("Function: %p (len: %d): ", x, (int)(func -> len));
132 for (i = 0; i < 20 && i < func -> len; i++) {
133 putchar((*(func -> fn))(i, func -> client_data));
135 if (i < func -> len) fputs("...", stdout);
140 /* Dump the internal representation of x to stdout */
141 void CORD_dump(CORD x)
143 CORD_dump_inner(x, 0);
147 CORD CORD_cat_char_star(CORD x, const char * y, size_t leny)
149 register size_t result_len;
150 register size_t lenx;
153 if (x == CORD_EMPTY) return(y);
154 if (leny == 0) return(x);
155 if (CORD_IS_STRING(x)) {
157 result_len = lenx + leny;
158 if (result_len <= SHORT_LIMIT) {
159 register char * result = GC_MALLOC_ATOMIC(result_len+1);
161 if (result == 0) OUT_OF_MEMORY;
162 memcpy(result, x, lenx);
163 memcpy(result + lenx, y, leny);
164 result[result_len] = '\0';
165 return((CORD) result);
172 register char * new_right;
173 register size_t right_len;
177 if (leny <= SHORT_LIMIT/2
178 && IS_CONCATENATION(x)
179 && CORD_IS_STRING(right = ((CordRep *)x) -> concatenation.right)) {
180 /* Merge y into right part of x. */
181 if (!CORD_IS_STRING(left = ((CordRep *)x) -> concatenation.left)) {
182 right_len = lenx - LEN(left);
183 } else if (((CordRep *)x) -> concatenation.left_len != 0) {
184 right_len = lenx - ((CordRep *)x) -> concatenation.left_len;
186 right_len = strlen(right);
188 result_len = right_len + leny; /* length of new_right */
189 if (result_len <= SHORT_LIMIT) {
190 new_right = GC_MALLOC_ATOMIC(result_len + 1);
191 if (new_right == 0) OUT_OF_MEMORY;
192 memcpy(new_right, right, right_len);
193 memcpy(new_right + right_len, y, leny);
194 new_right[result_len] = '\0';
199 /* Now fall through to concatenate the two pieces: */
201 if (CORD_IS_STRING(x)) {
204 depth = DEPTH(x) + 1;
207 depth = DEPTH(x) + 1;
209 result_len = lenx + leny;
212 /* The general case; lenx, result_len is known: */
213 register struct Concatenation * result;
215 result = GC_NEW(struct Concatenation);
216 if (result == 0) OUT_OF_MEMORY;
217 result->header = CONCAT_HDR;
218 result->depth = depth;
219 if (lenx <= MAX_LEFT_LEN) result->left_len = lenx;
220 result->len = result_len;
223 if (depth >= MAX_DEPTH) {
224 return(CORD_balance((CORD)result));
226 return((CORD) result);
232 CORD CORD_cat(CORD x, CORD y)
234 register size_t result_len;
236 register size_t lenx;
238 if (x == CORD_EMPTY) return(y);
239 if (y == CORD_EMPTY) return(x);
240 if (CORD_IS_STRING(y)) {
241 return(CORD_cat_char_star(x, y, strlen(y)));
242 } else if (CORD_IS_STRING(x)) {
244 depth = DEPTH(y) + 1;
246 register int depthy = DEPTH(y);
249 depth = DEPTH(x) + 1;
250 if (depthy >= depth) depth = depthy + 1;
252 result_len = lenx + LEN(y);
254 register struct Concatenation * result;
256 result = GC_NEW(struct Concatenation);
257 if (result == 0) OUT_OF_MEMORY;
258 result->header = CONCAT_HDR;
259 result->depth = depth;
260 if (lenx <= MAX_LEFT_LEN) result->left_len = lenx;
261 result->len = result_len;
264 if (depth >= MAX_DEPTH) {
265 return(CORD_balance((CORD)result));
267 return((CORD) result);
274 CORD CORD_from_fn(CORD_fn fn, void * client_data, size_t len)
276 if (len <= 0) return(0);
277 if (len <= SHORT_LIMIT) {
278 register char * result;
280 char buf[SHORT_LIMIT+1];
283 for (i = 0; i < len; i++) {
284 c = (*fn)(i, client_data);
285 if (c == '\0') goto gen_case;
289 result = GC_MALLOC_ATOMIC(len+1);
290 if (result == 0) OUT_OF_MEMORY;
293 return((CORD) result);
297 register struct Function * result;
299 result = GC_NEW(struct Function);
300 if (result == 0) OUT_OF_MEMORY;
301 result->header = FN_HDR;
302 /* depth is already 0 */
305 result->client_data = client_data;
306 return((CORD) result);
310 size_t CORD_len(CORD x)
324 char CORD_index_access_fn(size_t i, void * client_data)
326 register struct substr_args *descr = (struct substr_args *)client_data;
328 return(((char *)(descr->sa_cord))[i + descr->sa_index]);
331 char CORD_apply_access_fn(size_t i, void * client_data)
333 register struct substr_args *descr = (struct substr_args *)client_data;
334 register struct Function * fn_cord = &(descr->sa_cord->function);
336 return((*(fn_cord->fn))(i + descr->sa_index, fn_cord->client_data));
339 /* A version of CORD_substr that simply returns a function node, thus */
340 /* postponing its work. The fourth argument is a function that may */
341 /* be used for efficient access to the ith character. */
342 /* Assumes i >= 0 and i + n < length(x). */
343 CORD CORD_substr_closure(CORD x, size_t i, size_t n, CORD_fn f)
345 register struct substr_args * sa = GC_NEW(struct substr_args);
348 if (sa == 0) OUT_OF_MEMORY;
349 sa->sa_cord = (CordRep *)x;
351 result = CORD_from_fn(f, (void *)sa, n);
352 ((CordRep *)result) -> function.header = SUBSTR_HDR;
356 # define SUBSTR_LIMIT (10 * SHORT_LIMIT)
357 /* Substrings of function nodes and flat strings shorter than */
358 /* this are flat strings. Othewise we use a functional */
359 /* representation, which is significantly slower to access. */
361 /* A version of CORD_substr that assumes i >= 0, n > 0, and i + n < length(x).*/
362 CORD CORD_substr_checked(CORD x, size_t i, size_t n)
364 if (CORD_IS_STRING(x)) {
365 if (n > SUBSTR_LIMIT) {
366 return(CORD_substr_closure(x, i, n, CORD_index_access_fn));
368 register char * result = GC_MALLOC_ATOMIC(n+1);
370 if (result == 0) OUT_OF_MEMORY;
371 strncpy(result, x+i, n);
375 } else if (IS_CONCATENATION(x)) {
376 register struct Concatenation * conc
377 = &(((CordRep *)x) -> concatenation);
378 register size_t left_len;
379 register size_t right_len;
381 left_len = LEFT_LEN(conc);
382 right_len = conc -> len - left_len;
384 if (n == right_len) return(conc -> right);
385 return(CORD_substr_checked(conc -> right, i - left_len, n));
386 } else if (i+n <= left_len) {
387 if (n == left_len) return(conc -> left);
388 return(CORD_substr_checked(conc -> left, i, n));
390 /* Need at least one character from each side. */
391 register CORD left_part;
392 register CORD right_part;
393 register size_t left_part_len = left_len - i;
396 left_part = conc -> left;
398 left_part = CORD_substr_checked(conc -> left, i, left_part_len);
400 if (i + n == right_len + left_len) {
401 right_part = conc -> right;
403 right_part = CORD_substr_checked(conc -> right, 0,
406 return(CORD_cat(left_part, right_part));
408 } else /* function */ {
409 if (n > SUBSTR_LIMIT) {
411 /* Avoid nesting substring nodes. */
412 register struct Function * f = &(((CordRep *)x) -> function);
413 register struct substr_args *descr =
414 (struct substr_args *)(f -> client_data);
416 return(CORD_substr_closure((CORD)descr->sa_cord,
420 return(CORD_substr_closure(x, i, n, CORD_apply_access_fn));
424 register struct Function * f = &(((CordRep *)x) -> function);
425 char buf[SUBSTR_LIMIT+1];
426 register char * p = buf;
429 register int lim = i + n;
431 for (j = i; j < lim; j++) {
432 c = (*(f -> fn))(j, f -> client_data);
434 return(CORD_substr_closure(x, i, n, CORD_apply_access_fn));
439 result = GC_MALLOC_ATOMIC(n+1);
440 if (result == 0) OUT_OF_MEMORY;
447 CORD CORD_substr(CORD x, size_t i, size_t n)
449 register size_t len = CORD_len(x);
451 if (i >= len || n <= 0) return(0);
452 /* n < 0 is impossible in a correct C implementation, but */
453 /* quite possible under SunOS 4.X. */
454 if (i + n > len) n = len - i;
456 if (i < 0) ABORT("CORD_substr: second arg. negative");
457 /* Possible only if both client and C implementation are buggy. */
458 /* But empirically this happens frequently. */
460 return(CORD_substr_checked(x, i, n));
463 /* See cord.h for definition. We assume i is in range. */
464 int CORD_iter5(CORD x, size_t i, CORD_iter_fn f1,
465 CORD_batched_iter_fn f2, void * client_data)
467 if (x == 0) return(0);
468 if (CORD_IS_STRING(x)) {
469 register const char *p = x+i;
471 if (*p == '\0') ABORT("2nd arg to CORD_iter5 too big");
472 if (f2 != CORD_NO_FN) {
473 return((*f2)(p, client_data));
476 if ((*f1)(*p, client_data)) return(1);
481 } else if (IS_CONCATENATION(x)) {
482 register struct Concatenation * conc
483 = &(((CordRep *)x) -> concatenation);
487 register size_t left_len = LEFT_LEN(conc);
490 return(CORD_iter5(conc -> right, i - left_len, f1, f2,
494 if (CORD_iter5(conc -> left, i, f1, f2, client_data)) {
497 return(CORD_iter5(conc -> right, 0, f1, f2, client_data));
498 } else /* function */ {
499 register struct Function * f = &(((CordRep *)x) -> function);
501 register size_t lim = f -> len;
503 for (j = i; j < lim; j++) {
504 if ((*f1)((*(f -> fn))(j, f -> client_data), client_data)) {
513 int CORD_iter(CORD x, CORD_iter_fn f1, void * client_data)
515 return(CORD_iter5(x, 0, f1, CORD_NO_FN, client_data));
518 int CORD_riter4(CORD x, size_t i, CORD_iter_fn f1, void * client_data)
520 if (x == 0) return(0);
521 if (CORD_IS_STRING(x)) {
522 register const char *p = x + i;
527 if (c == '\0') ABORT("2nd arg to CORD_riter4 too big");
528 if ((*f1)(c, client_data)) return(1);
533 } else if (IS_CONCATENATION(x)) {
534 register struct Concatenation * conc
535 = &(((CordRep *)x) -> concatenation);
536 register CORD left_part = conc -> left;
537 register size_t left_len;
539 left_len = LEFT_LEN(conc);
541 if (CORD_riter4(conc -> right, i - left_len, f1, client_data)) {
544 return(CORD_riter4(left_part, left_len - 1, f1, client_data));
546 return(CORD_riter4(left_part, i, f1, client_data));
548 } else /* function */ {
549 register struct Function * f = &(((CordRep *)x) -> function);
553 if ((*f1)((*(f -> fn))(j, f -> client_data), client_data)) {
556 if (j == 0) return(0);
561 int CORD_riter(CORD x, CORD_iter_fn f1, void * client_data)
563 size_t len = CORD_len(x);
564 if (len == 0) return(0);
565 return(CORD_riter4(x, len - 1, f1, client_data));
569 * The following functions are concerned with balancing cords.
571 * Scan the cord from left to right, keeping the cord scanned so far
572 * as a forest of balanced trees of exponentialy decreasing length.
573 * When a new subtree needs to be added to the forest, we concatenate all
574 * shorter ones to the new tree in the appropriate order, and then insert
575 * the result into the forest.
576 * Crucial invariants:
577 * 1. The concatenation of the forest (in decreasing order) with the
578 * unscanned part of the rope is equal to the rope being balanced.
579 * 2. All trees in the forest are balanced.
580 * 3. forest[i] has depth at most i.
585 size_t len; /* Actual length of c */
588 static size_t min_len [ MAX_DEPTH ];
590 static int min_len_init = 0;
594 typedef ForestElement Forest [ MAX_DEPTH ];
595 /* forest[i].len >= fib(i+1) */
596 /* The string is the concatenation */
597 /* of the forest in order of DECREASING */
600 void CORD_init_min_len()
603 register size_t last, previous, current;
605 min_len[0] = previous = 1;
606 min_len[1] = last = 2;
607 for (i = 2; i < MAX_DEPTH; i++) {
608 current = last + previous;
609 if (current < last) /* overflow */ current = last;
610 min_len[i] = current;
614 CORD_max_len = last - 1;
619 void CORD_init_forest(ForestElement * forest, size_t max_len)
623 for (i = 0; i < MAX_DEPTH; i++) {
625 if (min_len[i] > max_len) return;
627 ABORT("Cord too long");
630 /* Add a leaf to the appropriate level in the forest, cleaning */
631 /* out lower levels as necessary. */
632 /* Also works if x is a balanced tree of concatenations; however */
633 /* in this case an extra concatenation node may be inserted above x; */
634 /* This node should not be counted in the statement of the invariants. */
635 void CORD_add_forest(ForestElement * forest, CORD x, size_t len)
638 register CORD sum = CORD_EMPTY;
639 register size_t sum_len = 0;
641 while (len > min_len[i + 1]) {
642 if (forest[i].c != 0) {
643 sum = CORD_cat(forest[i].c, sum);
644 sum_len += forest[i].len;
649 /* Sum has depth at most 1 greter than what would be required */
651 sum = CORD_cat(sum, x);
653 /* If x was a leaf, then sum is now balanced. To see this */
654 /* consider the two cases in which forest[i-1] either is or is */
656 while (sum_len >= min_len[i]) {
657 if (forest[i].c != 0) {
658 sum = CORD_cat(forest[i].c, sum);
659 sum_len += forest[i].len;
660 /* This is again balanced, since sum was balanced, and has */
661 /* allowable depth that differs from i by at most 1. */
668 forest[i].len = sum_len;
671 CORD CORD_concat_forest(ForestElement * forest, size_t expected_len)
677 while (sum_len != expected_len) {
678 if (forest[i].c != 0) {
679 sum = CORD_cat(forest[i].c, sum);
680 sum_len += forest[i].len;
687 /* Insert the frontier of x into forest. Balanced subtrees are */
688 /* treated as leaves. This potentially adds one to the depth */
689 /* of the final tree. */
690 void CORD_balance_insert(CORD x, size_t len, ForestElement * forest)
694 if (CORD_IS_STRING(x)) {
695 CORD_add_forest(forest, x, len);
696 } else if (IS_CONCATENATION(x)
697 && ((depth = DEPTH(x)) >= MAX_DEPTH
698 || len < min_len[depth])) {
699 register struct Concatenation * conc
700 = &(((CordRep *)x) -> concatenation);
701 size_t left_len = LEFT_LEN(conc);
703 CORD_balance_insert(conc -> left, left_len, forest);
704 CORD_balance_insert(conc -> right, len - left_len, forest);
705 } else /* function or balanced */ {
706 CORD_add_forest(forest, x, len);
711 CORD CORD_balance(CORD x)
716 if (x == 0) return(0);
717 if (CORD_IS_STRING(x)) return(x);
718 if (!min_len_init) CORD_init_min_len();
720 CORD_init_forest(forest, len);
721 CORD_balance_insert(x, len, forest);
722 return(CORD_concat_forest(forest, len));
726 /* Position primitives */
728 /* Private routines to deal with the hard cases only: */
730 /* P contains a prefix of the path to cur_pos. Extend it to a full */
731 /* path and set up leaf info. */
732 /* Return 0 if past the end of cord, 1 o.w. */
733 void CORD__extend_path(register CORD_pos p)
735 register struct CORD_pe * current_pe = &(p[0].path[p[0].path_len]);
736 register CORD top = current_pe -> pe_cord;
737 register size_t pos = p[0].cur_pos;
738 register size_t top_pos = current_pe -> pe_start_pos;
739 register size_t top_len = GEN_LEN(top);
741 /* Fill in the rest of the path. */
742 while(!CORD_IS_STRING(top) && IS_CONCATENATION(top)) {
743 register struct Concatenation * conc =
744 &(((CordRep *)top) -> concatenation);
745 register size_t left_len;
747 left_len = LEFT_LEN(conc);
749 if (pos >= top_pos + left_len) {
750 current_pe -> pe_cord = top = conc -> right;
751 current_pe -> pe_start_pos = top_pos = top_pos + left_len;
754 current_pe -> pe_cord = top = conc -> left;
755 current_pe -> pe_start_pos = top_pos;
760 /* Fill in leaf description for fast access. */
761 if (CORD_IS_STRING(top)) {
763 p[0].cur_start = top_pos;
764 p[0].cur_end = top_pos + top_len;
768 if (pos >= top_pos + top_len) p[0].path_len = CORD_POS_INVALID;
771 char CORD__pos_fetch(register CORD_pos p)
773 /* Leaf is a function node */
774 struct CORD_pe * pe = &((p)[0].path[(p)[0].path_len]);
775 CORD leaf = pe -> pe_cord;
776 register struct Function * f = &(((CordRep *)leaf) -> function);
778 if (!IS_FUNCTION(leaf)) ABORT("CORD_pos_fetch: bad leaf");
779 return ((*(f -> fn))(p[0].cur_pos - pe -> pe_start_pos, f -> client_data));
782 void CORD__next(register CORD_pos p)
784 register size_t cur_pos = p[0].cur_pos + 1;
785 register struct CORD_pe * current_pe = &((p)[0].path[(p)[0].path_len]);
786 register CORD leaf = current_pe -> pe_cord;
788 /* Leaf is not a string or we're at end of leaf */
789 p[0].cur_pos = cur_pos;
790 if (!CORD_IS_STRING(leaf)) {
792 register struct Function * f = &(((CordRep *)leaf) -> function);
793 register size_t start_pos = current_pe -> pe_start_pos;
794 register size_t end_pos = start_pos + f -> len;
796 if (cur_pos < end_pos) {
797 /* Fill cache and return. */
799 register size_t limit = cur_pos + FUNCTION_BUF_SZ;
800 register CORD_fn fn = f -> fn;
801 register void * client_data = f -> client_data;
803 if (limit > end_pos) {
806 for (i = cur_pos; i < limit; i++) {
807 p[0].function_buf[i - cur_pos] =
808 (*fn)(i - start_pos, client_data);
810 p[0].cur_start = cur_pos;
811 p[0].cur_leaf = p[0].function_buf;
812 p[0].cur_end = limit;
817 /* Pop the stack until we find two concatenation nodes with the */
818 /* same start position: this implies we were in left part. */
820 while (p[0].path_len > 0
821 && current_pe[0].pe_start_pos != current_pe[-1].pe_start_pos) {
825 if (p[0].path_len == 0) {
826 p[0].path_len = CORD_POS_INVALID;
831 CORD__extend_path(p);
834 void CORD__prev(register CORD_pos p)
836 register struct CORD_pe * pe = &(p[0].path[p[0].path_len]);
838 if (p[0].cur_pos == 0) {
839 p[0].path_len = CORD_POS_INVALID;
843 if (p[0].cur_pos >= pe -> pe_start_pos) return;
845 /* Beginning of leaf */
847 /* Pop the stack until we find two concatenation nodes with the */
848 /* different start position: this implies we were in right part. */
850 register struct CORD_pe * current_pe = &((p)[0].path[(p)[0].path_len]);
852 while (p[0].path_len > 0
853 && current_pe[0].pe_start_pos == current_pe[-1].pe_start_pos) {
859 CORD__extend_path(p);
862 #undef CORD_pos_fetch
865 #undef CORD_pos_to_index
866 #undef CORD_pos_to_cord
867 #undef CORD_pos_valid
869 char CORD_pos_fetch(register CORD_pos p)
871 if (p[0].cur_start <= p[0].cur_pos && p[0].cur_pos < p[0].cur_end) {
872 return(p[0].cur_leaf[p[0].cur_pos - p[0].cur_start]);
874 return(CORD__pos_fetch(p));
878 void CORD_next(CORD_pos p)
880 if (p[0].cur_pos < p[0].cur_end - 1) {
887 void CORD_prev(CORD_pos p)
889 if (p[0].cur_end != 0 && p[0].cur_pos > p[0].cur_start) {
896 size_t CORD_pos_to_index(CORD_pos p)
898 return(p[0].cur_pos);
901 CORD CORD_pos_to_cord(CORD_pos p)
903 return(p[0].path[0].pe_cord);
906 int CORD_pos_valid(CORD_pos p)
908 return(p[0].path_len != CORD_POS_INVALID);
911 void CORD_set_pos(CORD_pos p, CORD x, size_t i)
913 if (x == CORD_EMPTY) {
914 p[0].path_len = CORD_POS_INVALID;
917 p[0].path[0].pe_cord = x;
918 p[0].path[0].pe_start_pos = 0;
921 CORD__extend_path(p);