这个和脚本本身没关系吧
确切的问题大概是 为什么 Fixnum 对象的 id 方法 返回其本身的两倍 + 1 这样
这个..ruby设计上就是这样子 别问我 我不知道 ruby-1.8.7-p302---gc.c--2083-2148
[pre lang="c"]/*
* Document-method: __id__
* Document-method: object_id
*
* call-seq:
* obj.__id__ => fixnum
* obj.object_id => fixnum
*
* Returns an integer identifier for <i>obj</i>. The same number will
* be returned on all calls to <code>id</code> for a given object, and
* no two active objects will share an id.
* <code>Object#object_id</code> is a different concept from the
* <code>:name</code> notation, which returns the symbol id of
* <code>name</code>. Replaces the deprecated <code>Object#id</code>.
*/
/*
* call-seq:
* obj.hash => fixnum
*
* Generates a <code>Fixnum</code> hash value for this object. This
* function must have the property that <code>a.eql?(b)</code> implies
* <code>a.hash == b.hash</code>. The hash value is used by class
* <code>Hash</code>. Any hash value that exceeds the capacity of a
* <code>Fixnum</code> will be truncated before being used.
*/
VALUE
rb_obj_id(VALUE obj)
{
/*
* 32-bit VALUE space
* MSB ------------------------ LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol ssssssssssssssssssssssss00001110
* object oooooooooooooooooooooooooooooo00 = 0 (mod sizeof(RVALUE))
* fixnum fffffffffffffffffffffffffffffff1
*
* object_id space
* LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol 000SSSSSSSSSSSSSSSSSSSSSSSSSSS0 S...S % A = 4 (S...S = s...s * A + 4)
* object oooooooooooooooooooooooooooooo0 o...o % A = 0
* fixnum fffffffffffffffffffffffffffffff1 bignum if required
*
* where A = sizeof(RVALUE)/4
*
* sizeof(RVALUE) is
* 20 if 32-bit, double is 4-byte aligned
* 24 if 32-bit, double is 8-byte aligned
* 40 if 64-bit
*/
if (TYPE(obj) == T_SYMBOL) {
return (SYM2ID(obj) * sizeof(RVALUE) + (4 << 2)) | FIXNUM_FLAG;
}
if (SPECIAL_CONST_P(obj)) {
return LONG2NUM((long)obj);
}
return (VALUE)((long)obj|FIXNUM_FLAG);
}[/pre]
ruby内一切对象即VALUE 参考上面
TYPE(xx) 返回 xx 的类型
SYM2ID(xx) 将xx右移8位
FIXNUM_FLAG = 1
SPECIAL_CONST_P(xx) xx是否为false true nil undef symbol or fixnum
LONG2NUM(xx) 把c数据xx转换为ruby数值对象
RVALUE 同文件309行起
[pre lang="c"]#if defined(_MSC_VER) || defined(__BORLANDC__) || defined(__CYGWIN__)
#pragma pack(push, 1) /* magic for reducing sizeof(RVALUE): 24 -> 20 */
#endif