Backport #809

closed

String#ord and String#[gs]etbyte for 1.8

Added by shinh (Shinichiro Hamaji) over 15 years ago. Updated almost 13 years ago.

Status:

Closed

Assignee:

knu (Akinori MUSHA)

[ruby-dev:37247]

Description

=begin
Ruby1.9 でコードを書いている時に、 1.8 でも動くようにしとくかなぁ…
と思う時に最も困るのが個人的には String#[] の挙動の変化なのですが、
1.9 の ord, getbyte, setbyte を backport しておくわけにはいけないもんでしょうか。

Index: string.c¶

--- string.c (revision 20448)
+++ string.c (working copy)
@@ -2473,6 +2473,51 @@

call-seq:

str.getbyte(index)          => 0 .. 255

- returns the indexth byte as an integer.
*/
+static VALUE
+rb_str_getbyte(VALUE str, VALUE index)
+{
long pos = NUM2LONG(index);
if (pos < 0)
pos += RSTRING_LEN(str);
if (pos < 0 || RSTRING_LEN(str) <= pos)
return Qnil;
return INT2FIX((unsigned char)RSTRING_PTR(str)[pos]);
+}

+/*

- call-seq:
- ```
str.setbyte(index, int) => int
```
- modifies the indexth byte as int.
*/
+static VALUE
+rb_str_setbyte(VALUE str, VALUE index, VALUE value)
+{
long pos = NUM2LONG(index);
int byte = NUM2INT(value);
rb_str_modify(str);
if (pos < -RSTRING_LEN(str) || RSTRING_LEN(str) <= pos)
rb_raise(rb_eIndexError, "index %ld out of string", pos);
if (pos < 0)
pos += RSTRING_LEN(str);
RSTRING_PTR(str)[pos] = byte;
return value;
+}

+/*

- call-seq:
- ```
str.reverse   => new_str
```
- Returns a new string with the characters from str in reverse order.
  @@ -4556,6 +4601,24 @@

call-seq:

- ```
str.ord   => integer
```
- Return the Integer ordinal of a one-character string.
- ```
"a".ord         #=> 97
```
*/

+VALUE
+rb_str_ord(VALUE s)
+{

if (RSTRING_LEN(s) <= 0)
rb_raise(rb_eArgError, "empty string");
return INT2FIX(*RSTRING_PTR(s) & 0xff);
+}

+/*

- call-seq:
- ```
str.sum(n=16)   => integer
```
- Returns a basic n-bit checksum of the characters in str,
  @@ -4959,6 +5022,8 @@
  rb_define_method(rb_cString, "index", rb_str_index_m, -1);
  rb_define_method(rb_cString, "rindex", rb_str_rindex_m, -1);
  rb_define_method(rb_cString, "replace", rb_str_replace, 1);
rb_define_method(rb_cString, "getbyte", rb_str_getbyte, 1);
rb_define_method(rb_cString, "setbyte", rb_str_setbyte, 2);

rb_define_method(rb_cString, "to_i", rb_str_to_i, -1);
rb_define_method(rb_cString, "to_f", rb_str_to_f, 0);
@@ -4987,6 +5052,7 @@
rb_define_method(rb_cString, "crypt", rb_str_crypt, 1);
rb_define_method(rb_cString, "intern", rb_str_intern, 0);
rb_define_method(rb_cString, "to_sym", rb_str_intern, 0);
rb_define_method(rb_cString, "ord", rb_str_ord, 0);

rb_define_method(rb_cString, "include?", rb_str_include, 1);
rb_define_method(rb_cString, "start_with?", rb_str_start_with, -1);
Index: test/ruby/test_string.rb
===================================================================
--- test/ruby/test_string.rb (revision 20448)
+++ test/ruby/test_string.rb (working copy)
@@ -77,4 +77,28 @@
assert_equal("aaaaaaaaaaaa", "zzzzzzzzzzz".succ!)
assert_equal("aaaaaaaaaaaaaaaaaaaaaaaa", "zzzzzzzzzzzzzzzzzzzzzzz".succ!)
end
def test_getbyte
assert_equal(0x82, "\xE3\x81\x82\xE3\x81\x84".getbyte(2))
assert_equal(0x82, "\xE3\x81\x82\xE3\x81\x84".getbyte(-4))
assert_nil("\xE3\x81\x82\xE3\x81\x84".getbyte(100))
end
def test_setbyte
s = "\xE3\x81\x82\xE3\x81\x84"
s.setbyte(2, 0x84)
assert_equal("\xE3\x81\x84\xE3\x81\x84", s)
s = "\xE3\x81\x82\xE3\x81\x84"
assert_raise(IndexError) { s.setbyte(100, 0) }
s = "\xE3\x81\x82\xE3\x81\x84"
s.setbyte(-4, 0x84)
assert_equal("\xE3\x81\x84\xE3\x81\x84", s)
end
def test_ord
assert_equal(0xe3, "\xE3\x81\x82\xE3\x81\x84".ord)
assert_raise(ArgumentError) { "".ord }
end
end
=end