@@ -1278,6 +1278,86 @@ mrb_str_uminus(mrb_state *mrb, mrb_value str)
12781278return mrb_obj_freeze(mrb, mrb_str_dup(mrb, str));
12791279}
128012801281+static mrb_value
1282+str_bytesplice(mrb_state *mrb, mrb_value str, mrb_int idx1, mrb_int len1, mrb_value replace, mrb_int idx2, mrb_int len2)
1283+{
1284+struct RString *s = RSTRING(str);
1285+if (RSTR_LEN(s) <= idx1 || RSTRING_LEN(replace) <= idx2) {
1286+mrb_raise(mrb, E_INDEX_ERROR, "index out of string");
1287+ }
1288+if (RSTR_LEN(s) <= idx1+len1) {
1289+len1 = RSTR_LEN(s) - idx1;
1290+ }
1291+if (RSTRING_LEN(replace) <= idx2+len2) {
1292+len2 = RSTRING_LEN(replace) - idx2;
1293+ }
1294+if (len2 == 0) return replace;
1295+mrb_str_modify(mrb, s);
1296+if (len1 >= len2) {
1297+memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
1298+if (len1 > len2) {
1299+memmove(RSTR_PTR(s)+idx1+len2, RSTR_PTR(s)+idx1+len1, RSTR_LEN(s)-(idx1+len1));
1300+RSTR_SET_LEN(s, RSTR_LEN(s)-(len1-len2));
1301+ }
1302+ }
1303+else { /* len1 < len2 */
1304+mrb_int slen = RSTR_LEN(s);
1305+mrb_str_resize(mrb, str, slen+len2-len1);
1306+memmove(RSTR_PTR(s)+idx1+len2, RSTR_PTR(s)+idx1+len1, slen-(idx1+len1));
1307+memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
1308+ }
1309+return replace;
1310+}
1311+1312+/*
1313+ * call-seq:
1314+ * bytesplice(index, length, str) -> string
1315+ * bytesplice(index, length, str, str_index, str_length) -> string
1316+ * bytesplice(range, str) -> string
1317+ * bytesplice(range, str, str_range) -> string
1318+ *
1319+ * Replaces some or all of the content of +self+ with +str+, and returns +self+.
1320+ * The portion of the string affected is determined using
1321+ * the same criteria as String#byteslice, except that +length+ cannot be omitted.
1322+ * If the replacement string is not the same length as the text it is replacing,
1323+ * the string will be adjusted accordingly.
1324+ *
1325+ * If +str_index+ and +str_length+, or +str_range+ are given, the content of +self+ is replaced by str.byteslice(str_index, str_length) or str.byteslice(str_range); however the substring of +str+ is not allocated as a new string.
1326+ *
1327+ * The form that take an Integer will raise an IndexError if the value is out
1328+ * of range; the Range form will raise a RangeError.
1329+ * If the beginning or ending offset does not land on character (codepoint)
1330+ * boundary, an IndexError will be raised.
1331+ */
1332+static mrb_value
1333+mrb_str_bytesplice(mrb_state *mrb, mrb_value str)
1334+{
1335+mrb_int idx1, len1, idx2, len2;
1336+mrb_value range1, range2, replace;
1337+switch (mrb_get_argc(mrb)) {
1338+case 3:
1339+mrb_get_args(mrb, "ooo", &range1, &replace, &range2);
1340+if (mrb_integer_p(range1)) {
1341+mrb_get_args(mrb, "iiS", &idx1, &len1, &replace);
1342+return str_bytesplice(mrb, str, idx1, len1, replace, 0, RSTRING_LEN(replace));
1343+ }
1344+if (mrb_range_beg_len(mrb, range1, &idx1, &len1, RSTRING_LEN(str), FALSE) != MRB_RANGE_OK) break;
1345+if (mrb_range_beg_len(mrb, range2, &idx2, &len2, RSTRING_LEN(replace), FALSE) != MRB_RANGE_OK) break;
1346+return str_bytesplice(mrb, str, idx1, len1, replace, idx2, len2);
1347+case 5:
1348+mrb_get_args(mrb, "iiSii", &idx1, &len1, &replace, &idx2, &len2);
1349+return str_bytesplice(mrb, str, idx1, len1, replace, idx2, len2);
1350+case 2:
1351+mrb_get_args(mrb, "oS", &range1, &replace);
1352+if (mrb_range_beg_len(mrb, range1, &idx1, &len1, RSTRING_LEN(str), FALSE) == MRB_RANGE_OK) {
1353+return str_bytesplice(mrb, str, idx1, len1, replace, 0, RSTRING_LEN(replace));
1354+ }
1355+default:
1356+break;
1357+ }
1358+mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong number of arumgnts");
1359+}
1360+12811361void
12821362mrb_mruby_string_ext_gem_init(mrb_state* mrb)
12831363{
@@ -1315,6 +1395,7 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb)
13151395mrb_define_method(mrb, s, "casecmp?", mrb_str_casecmp_p, MRB_ARGS_REQ(1));
13161396mrb_define_method(mrb, s, "+@", mrb_str_uplus, MRB_ARGS_REQ(1));
13171397mrb_define_method(mrb, s, "-@", mrb_str_uminus, MRB_ARGS_REQ(1));
1398+mrb_define_method(mrb, s, "bytesplice", mrb_str_bytesplice, MRB_ARGS_ANY());
1318139913191400mrb_define_method(mrb, s, "__lines", mrb_str_lines, MRB_ARGS_NONE());
13201401