dir.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "vi.h"
   5
   6 #define CR2L            "ءآأؤإئابةتثجحخدذرزسشصضطظعغـفقكلمنهوىييپچژکگی‌‍؛،»«؟"
   7 #define CNEUT           "-!\"#$%&'()*+,./:;<=>?@^_`{|}~ "
   8
   9 /* direction context patterns */
  10 static struct dcontext {
  11         int dir;
  12         char *pat;
  13 } dcontexts[] = {
  14         {-1, "^[" CR2L "]"},
  15         {+1, "^[a-zA-Z_0-9]"},
  16 };
  17
  18 /* direction marks */
  19 static struct dmark {
  20         int ctx;        /* the direction context for this mark; 0 means any */
  21         int dir;        /* the direction of matched text */
  22         int grp;        /* the nested subgroup; 0 means no groups */
  23         char *pat;
  24 } dmarks[] = {
  25         {+0, +1, 0, "$([^$]+)\\$"},
  26         {+0, +1, 1, "\\\\\\*\\[([^]]+)\\]"},
  27         {+1, -1, 0, "[" CR2L "][" CNEUT CR2L "]*[" CR2L "]"},
  28         {-1, +1, 0, "[a-zA-Z0-9_][^" CR2L "\\\\`$']*[a-zA-Z0-9_]"},
  29 };
  30
  31 static struct rset *dir_rslr;   /* pattern of marks for left-to-right strings */
  32 static struct rset *dir_rsrl;   /* pattern of marks for right-to-left strings */
  33 static struct rset *dir_rsctx;  /* direction context patterns */
  34
  35 static int dir_match(char **chrs, int beg, int end, int ctx, int *rec,
  36                 int *r_beg, int *r_end, int *c_beg, int *c_end, int *dir)
  37 {
  38         int subs[16 * 2];
  39         struct rset *rs = ctx < 0 ? dir_rsrl : dir_rslr;
  40         struct sbuf *str = sbuf_make();
  41         int flg = (beg ? RE_NOTBOL : 0) | (chrs[end][0] ? RE_NOTEOL : 0);
  42         int found;
  43         sbuf_mem(str, chrs[beg], chrs[end] - chrs[beg]);
  44         found = rset_find(rs, sbuf_buf(str), LEN(subs) / 2, subs, flg);
  45         if (found >= 0 && r_beg && r_end && c_beg && c_end) {
  46                 struct dmark *dm = &dmarks[found];
  47                 char *s = sbuf_buf(str);
  48                 int grp = dm->grp;
  49                 *r_beg = beg + uc_off(s, subs[0]);
  50                 *r_end = beg + uc_off(s, subs[1]);
  51                 *c_beg = subs[grp * 2 + 0] >= 0 ?
  52                         beg + uc_off(s, subs[grp * 2 + 0]) : *r_beg;
  53                 *c_end = subs[grp * 2 + 1] >= 0 ?
  54                         beg + uc_off(s, subs[grp * 2 + 1]) : *r_end;
  55                 *dir = dm->dir;
  56                 *rec = grp > 0;
  57         }
  58         sbuf_free(str);
  59         return found < 0;
  60 }
  61
  62 static void dir_reverse(int *ord, int beg, int end)
  63 {
  64         end--;
  65         while (beg < end) {
  66                 int tmp = ord[beg];
  67                 ord[beg] = ord[end];
  68                 ord[end] = tmp;
  69                 beg++;
  70                 end--;
  71         }
  72 }
  73
  74 /* reorder the characters based on direction marks and characters */
  75 static void dir_fix(char **chrs, int *ord, int dir, int beg, int end)
  76 {
  77         int r_beg, r_end, c_beg, c_end;
  78         int c_dir, c_rec;
  79         while (beg < end && !dir_match(chrs, beg, end, dir, &c_rec,
  80                                 &r_beg, &r_end, &c_beg, &c_end, &c_dir)) {
  81                 if (dir < 0)
  82                         dir_reverse(ord, r_beg, r_end);
  83                 if (c_dir < 0)
  84                         dir_reverse(ord, c_beg, c_end);
  85                 if (c_beg == r_beg)
  86                         c_beg++;
  87                 if (c_rec)
  88                         dir_fix(chrs, ord, c_dir, c_beg, c_end);
  89                 beg = r_end;
  90         }
  91 }
  92
  93 int dir_context(char *s)
  94 {
  95         int found;
  96         if (xdir == 'L')
  97                 return +1;
  98         if (xdir == 'R')
  99                 return -1;
 100         found = rset_find(dir_rsctx, s ? s : "", 0, NULL, 0);
 101         if (found >= 0)
 102                 return dcontexts[found].dir;
 103         return xdir == 'r' ? -1 : +1;
 104 }
 105
 106 /* reorder the characters in s */
 107 void dir_reorder(char *s, int *ord)
 108 {
 109         int n;
 110         char **chrs = uc_chop(s, &n);
 111         int dir = dir_context(s);
 112         if (n && chrs[n - 1][0] == '\n') {
 113                 ord[n - 1] = n - 1;
 114                 n--;
 115         }
 116         dir_fix(chrs, ord, dir, 0, n);
 117         free(chrs);
 118 }
 119
 120 void dir_init(void)
 121 {
 122         char *relr[128];
 123         char *rerl[128];
 124         char *ctx[128];
 125         int i;
 126         for (i = 0; i < LEN(dmarks); i++) {
 127                 relr[i] = dmarks[i].ctx >= 0 ? dmarks[i].pat : NULL;
 128                 rerl[i] = dmarks[i].ctx <= 0 ? dmarks[i].pat : NULL;
 129         }
 130         dir_rslr = rset_make(LEN(dmarks), relr, 0);
 131         dir_rsrl = rset_make(LEN(dmarks), rerl, 0);
 132         for (i = 0; i < LEN(dcontexts); i++)
 133                 ctx[i] = dcontexts[i].pat;
 134         dir_rsctx = rset_make(LEN(dcontexts), ctx, 0);
 135 }
 136
 137 void dir_done(void)
 138 {
 139         rset_free(dir_rslr);
 140         rset_free(dir_rsrl);
 141         rset_free(dir_rsctx);
 142 }