mruby-string-ext/string.c: new method String#byteslice

This commit is contained in:
Yukihiro "Matz" Matsumoto
2023-01-27 23:00:05 +09:00
parent 7b27346386
commit 52746479a3
+81
View File
@@ -1278,6 +1278,86 @@ mrb_str_uminus(mrb_state *mrb, mrb_value str)
return mrb_obj_freeze(mrb, mrb_str_dup(mrb, str));
}
static mrb_value
str_bytesplice(mrb_state *mrb, mrb_value str, mrb_int idx1, mrb_int len1, mrb_value replace, mrb_int idx2, mrb_int len2)
{
struct RString *s = RSTRING(str);
if (RSTR_LEN(s) <= idx1 || RSTRING_LEN(replace) <= idx2) {
mrb_raise(mrb, E_INDEX_ERROR, "index out of string");
}
if (RSTR_LEN(s) <= idx1+len1) {
len1 = RSTR_LEN(s) - idx1;
}
if (RSTRING_LEN(replace) <= idx2+len2) {
len2 = RSTRING_LEN(replace) - idx2;
}
if (len2 == 0) return replace;
mrb_str_modify(mrb, s);
if (len1 >= len2) {
memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
if (len1 > len2) {
memmove(RSTR_PTR(s)+idx1+len2, RSTR_PTR(s)+idx1+len1, RSTR_LEN(s)-(idx1+len1));
RSTR_SET_LEN(s, RSTR_LEN(s)-(len1-len2));
}
}
else { /* len1 < len2 */
mrb_int slen = RSTR_LEN(s);
mrb_str_resize(mrb, str, slen+len2-len1);
memmove(RSTR_PTR(s)+idx1+len2, RSTR_PTR(s)+idx1+len1, slen-(idx1+len1));
memmove(RSTR_PTR(s)+idx1, RSTRING_PTR(replace)+idx2, len2);
}
return replace;
}
/*
* call-seq:
* bytesplice(index, length, str) -> string
* bytesplice(index, length, str, str_index, str_length) -> string
* bytesplice(range, str) -> string
* bytesplice(range, str, str_range) -> string
*
* Replaces some or all of the content of +self+ with +str+, and returns +self+.
* The portion of the string affected is determined using
* the same criteria as String#byteslice, except that +length+ cannot be omitted.
* If the replacement string is not the same length as the text it is replacing,
* the string will be adjusted accordingly.
*
* 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.
*
* The form that take an Integer will raise an IndexError if the value is out
* of range; the Range form will raise a RangeError.
* If the beginning or ending offset does not land on character (codepoint)
* boundary, an IndexError will be raised.
*/
static mrb_value
mrb_str_bytesplice(mrb_state *mrb, mrb_value str)
{
mrb_int idx1, len1, idx2, len2;
mrb_value range1, range2, replace;
switch (mrb_get_argc(mrb)) {
case 3:
mrb_get_args(mrb, "ooo", &range1, &replace, &range2);
if (mrb_integer_p(range1)) {
mrb_get_args(mrb, "iiS", &idx1, &len1, &replace);
return str_bytesplice(mrb, str, idx1, len1, replace, 0, RSTRING_LEN(replace));
}
if (mrb_range_beg_len(mrb, range1, &idx1, &len1, RSTRING_LEN(str), FALSE) != MRB_RANGE_OK) break;
if (mrb_range_beg_len(mrb, range2, &idx2, &len2, RSTRING_LEN(replace), FALSE) != MRB_RANGE_OK) break;
return str_bytesplice(mrb, str, idx1, len1, replace, idx2, len2);
case 5:
mrb_get_args(mrb, "iiSii", &idx1, &len1, &replace, &idx2, &len2);
return str_bytesplice(mrb, str, idx1, len1, replace, idx2, len2);
case 2:
mrb_get_args(mrb, "oS", &range1, &replace);
if (mrb_range_beg_len(mrb, range1, &idx1, &len1, RSTRING_LEN(str), FALSE) == MRB_RANGE_OK) {
return str_bytesplice(mrb, str, idx1, len1, replace, 0, RSTRING_LEN(replace));
}
default:
break;
}
mrb_raise(mrb, E_ARGUMENT_ERROR, "wrong number of arumgnts");
}
void
mrb_mruby_string_ext_gem_init(mrb_state* mrb)
{
@@ -1315,6 +1395,7 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb)
mrb_define_method(mrb, s, "casecmp?", mrb_str_casecmp_p, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "+@", mrb_str_uplus, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "-@", mrb_str_uminus, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "bytesplice", mrb_str_bytesplice, MRB_ARGS_ANY());
mrb_define_method(mrb, s, "__lines", mrb_str_lines, MRB_ARGS_NONE());