2.4.4.17.5 Literal Tokens
|
Token Type |
Byte-Code |
Token Data Encoding |
|---|---|---|
|
Invalid token |
0x00 |
Padding value. |
|
Signed int8 |
0x01 |
1 QWORD, least significant byte first, for the value, 2's complement, -128 to +127. 1 BYTE for sign. (possible values for sign in the following table) . 1 BYTE for base. (possible values for base in the following table). |
|
Signed int16 |
0x02 |
1 QWORD, least significant byte first, 2's complement, -32768 to +32767. 1 BYTE for sign. 1 BYTE for base. |
|
Signed int32 |
0x03 |
1 QWORD, least significant byte first, 2's complement. 1 BYTE for sign. 1 BYTE for base. |
|
Signed int64 |
0x04 |
1 QWORD, least significant byte first, 2's complement. 1 BYTE for sign. 1 BYTE for base. |
|
Unicode String |
0x10 |
1 DWORD for the length in bytes. 1 WORD for each Unicode character. Characters are stored LSB first. Strings are not null-terminated. |
|
Octet String |
0x18 |
Custom data is represented as a contiguous sequence of bytes. 1 DWORD for the length in bytes. 1 BYTE for each data octet. |
|
Composite |
0x50 |
1 DWORD that specifies the entire length in bytes of the entire set of elements. List type--can be heterogeneous. Elements are stored in contiguous fashion according to the built-in data type storage rules. |
|
SID |
0x51 |
1 DWORD that specifies the entire length in bytes of the SID. SID in binary representation (as specified in section 2.4.2.2.) |
Tokens in the preceding table that contain a base MUST include a base code from the following table.
|
Base |
Code |
Description |
|---|---|---|
|
8 |
0x01 |
Octal |
|
10 |
0x02 |
Decimal |
|
16 |
0x03 |
Hexadecimal |
Tokens in the preceding table that contain signs MUST include a sign code from the following table.
Relational operators interpret no sign (0x03) as positive.
Relational operators MUST use this to determine the sign of the literal during evaluation.
|
Sign |
Code |
Description |
|---|---|---|
|
+ |
0x01 |
Plus sign in condition. |
|
- |
0x02 |
Minus sign in condition. |
|
None |
0x03 |
No sign in condition. |
Thus the decimal value -1 encoded as a signed int64 would have the following binary representation (byte code, QWORD, sign byte, base byte):
-
0x04 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0x02 0x02
There are several things to note in the example. The sign and base bytes are used for display of the value. Even though the base byte indicates base 10, the value is stored as a 2's complement binary value. However, it will be displayed as a base 10 number.
The sign byte is handled similarly though with one important difference. If the sign byte indicates no sign, the value is treated as a positive number when displayed but appears with no explicit sign. However, when the value is used with a relational operator, the sign byte overrides the 2's complement sign.