text-util.c

   1 #include "text-util.h"
   2 #include "util.h"
   3 #include <wchar.h>
   4 #include <errno.h>
   5 #include <stdlib.h>
   6
   7 bool text_range_valid(const Filerange *r) {
   8         return r->start != EPOS && r->end != EPOS && r->start <= r->end;
   9 }
  10
  11 size_t text_range_size(const Filerange *r) {
  12         return text_range_valid(r) ? r->end - r->start : 0;
  13 }
  14
  15 Filerange text_range_empty(void) {
  16         return (Filerange){ .start = EPOS, .end = EPOS };
  17 }
  18
  19 Filerange text_range_union(const Filerange *r1, const Filerange *r2) {
  20         if (!text_range_valid(r1))
  21                 return *r2;
  22         if (!text_range_valid(r2))
  23                 return *r1;
  24         return (Filerange) {
  25                 .start = MIN(r1->start, r2->start),
  26                 .end = MAX(r1->end, r2->end),
  27         };
  28 }
  29
  30 Filerange text_range_intersect(const Filerange *r1, const Filerange *r2) {
  31         if (!text_range_overlap(r1, r2))
  32                 return text_range_empty();
  33         return text_range_new(MAX(r1->start, r2->start), MIN(r1->end, r2->end));
  34 }
  35
  36 Filerange text_range_new(size_t a, size_t b) {
  37         return (Filerange) {
  38                 .start = MIN(a, b),
  39                 .end = MAX(a, b),
  40         };
  41 }
  42
  43 bool text_range_equal(const Filerange *r1, const Filerange *r2) {
  44         if (!text_range_valid(r1) && !text_range_valid(r2))
  45                 return true;
  46         return r1->start == r2->start && r1->end == r2->end;
  47 }
  48
  49 bool text_range_overlap(const Filerange *r1, const Filerange *r2) {
  50         if (!text_range_valid(r1) || !text_range_valid(r2))
  51                 return false;
  52         return r1->start < r2->end && r2->start < r1->end;
  53 }
  54
  55 bool text_range_contains(const Filerange *r, size_t pos) {
  56         return text_range_valid(r) && r->start <= pos && pos <= r->end;
  57 }
  58
  59 int text_char_count(const char *data, size_t len) {
  60         int count = 0;
  61         mbstate_t ps = { 0 };
  62         while (len > 0) {
  63                 wchar_t wc;
  64                 size_t wclen = mbrtowc(&wc, data, len, &ps);
  65                 if (wclen == (size_t)-1 && errno == EILSEQ) {
  66                         ps = (mbstate_t){0};
  67                         count++;
  68                         while (!ISUTF8(*data))
  69                                 data++, len--;
  70                 } else if (wclen == (size_t)-2) {
  71                         break;
  72                 } else if (wclen == 0) {
  73                         count++;
  74                         data++;
  75                         len--;
  76                 } else {
  77                         int width = wcwidth(wc);
  78                         if (width != 0)
  79                                 count++;
  80                         data += wclen;
  81                         len -= wclen;
  82                 }
  83         }
  84         return count;
  85 }
  86
  87 int text_string_width(const char *data, size_t len) {
  88
  89         int width = 0;
  90         mbstate_t ps = { 0 };
  91         const char *s = data;
  92
  93         while (len > 0) {
  94                 wchar_t wc;
  95                 size_t wclen = mbrtowc(&wc, s, len, &ps);
  96                 if (wclen == (size_t)-1 && errno == EILSEQ) {
  97                         ps = (mbstate_t){0};
  98                         /* assume a replacement symbol will be displayed */
  99                         width++;
 100                         wclen = 1;
 101                 } else if (wclen == (size_t)-2) {
 102                         /* do nothing, advance to next character */
 103                         wclen = 1;
 104                 } else if (wclen == 0) {
 105                         /* assume NUL byte will be displayed as ^@ */
 106                         width += 2;
 107                         wclen = 1;
 108                 } else if (wc == L'\t') {
 109                         width++;
 110                         wclen = 1;
 111                 } else {
 112                         int w = wcwidth(wc);
 113                         if (w == -1)
 114                                 w = 2; /* assume non-printable will be displayed as ^{char} */
 115                         width += w;
 116                 }
 117                 len -= wclen;
 118                 s += wclen;
 119         }
 120
 121         return width;
 122 }