+const char *
+uc_name (ucs4_t uc, char buffer[16])
+{
+ if (uc >= 0x20 && uc < 0x7f)
+ snprintf (buffer, 16, "`%c'", uc);
+ else
+ snprintf (buffer, 16, "U+%04X", uc);
+ return buffer;
+}
+\f
+bool
+get_encoding_info (struct encoding_info *e, const char *name)
+{
+ const struct substring in = SS_LITERAL_INITIALIZER (
+ "\t\n\v\f\r "
+ "!\"#$%&'()*+,-./0123456789:;<=>?@"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`"
+ "abcdefghijklmnopqrstuvwxyz{|}~");
+
+ struct substring out, cr, lf;
+ bool ok;
+
+ memset (e, 0, sizeof *e);
+
+ cr = recode_substring_pool (name, "UTF-8", ss_cstr ("\r"), NULL);
+ lf = recode_substring_pool (name, "UTF-8", ss_cstr ("\n"), NULL);
+ ok = cr.length >= 1 && cr.length <= MAX_UNIT && cr.length == lf.length;
+ if (!ok)
+ {
+ fprintf (stderr, "warning: encoding `%s' is not supported.\n", name);
+ ss_dealloc (&cr);
+ ss_dealloc (&lf);
+ ss_alloc_substring (&cr, ss_cstr ("\r"));
+ ss_alloc_substring (&lf, ss_cstr ("\n"));
+ }
+
+ e->unit = cr.length;
+ memcpy (e->cr, cr.string, e->unit);
+ memcpy (e->lf, lf.string, e->unit);
+
+ ss_dealloc (&cr);
+ ss_dealloc (&lf);
+
+ out = recode_substring_pool ("UTF-8", name, in, NULL);
+ e->is_ascii_compatible = ss_equals (in, out);
+ ss_dealloc (&out);
+
+ return ok;
+}
+
+bool
+is_encoding_ascii_compatible (const char *encoding)
+{
+ struct encoding_info e;
+
+ get_encoding_info (&e, encoding);
+ return e.is_ascii_compatible;
+}