tabs and tab overview

misc.c

@@ -0,0 +1,63 @@
+#include "misc.h"
+#include "char32.h"
+#include <stdlib.h>
+
+bool
+isword(char32_t wc, bool spaces_only, const char32_t *delimiters)
+{
+    if (spaces_only)
+        return isc32graph(wc);
+
+    if (c32chr(delimiters, wc) != NULL)
+        return false;
+
+    return isc32graph(wc);
+}
+
+void
+timespec_add(const struct timespec *a, const struct timespec *b,
+             struct timespec *res)
+{
+    const long one_sec_in_ns = 1000000000;
+
+    res->tv_sec = a->tv_sec + b->tv_sec;
+    res->tv_nsec = a->tv_nsec + b->tv_nsec;
+    /* tv_nsec may be negative */
+    if (res->tv_nsec >= one_sec_in_ns) {
+        res->tv_sec++;
+        res->tv_nsec -= one_sec_in_ns;
+    }
+}
+
+void
+timespec_sub(const struct timespec *a, const struct timespec *b,
+             struct timespec *res)
+{
+    const long one_sec_in_ns = 1000000000;
+
+    res->tv_sec = a->tv_sec - b->tv_sec;
+    res->tv_nsec = a->tv_nsec - b->tv_nsec;
+    /* tv_nsec may be negative */
+    if (res->tv_nsec < 0) {
+        res->tv_sec--;
+        res->tv_nsec += one_sec_in_ns;
+    }
+}
+
+bool
+is_valid_utf8_and_printable(const char *value)
+{
+    char32_t *wide = ambstoc32(value);
+    if (wide == NULL)
+        return false;
+
+    for (const char32_t *c = wide; *c != U'\0'; c++) {
+        if (!isc32print(*c)) {
+            free(wide);
+            return false;
+        }
+    }
+
+    free(wide);
+    return true;
+}