int8
| Property | Value |
|---|---|
| Size | 1 byte (8 bits) |
| Minimum value | −27 = −128 |
| Maximum value | 27−1 = 127 |
| Literal suffix | i8 |
| Representation | Two's complement |
| Hardware support | Native on all supported targets |
int8 is the narrowest signed integer in Rux — a fixed-width type whose size is identical on every target platform. Like all signed types it uses two's complement: the most significant bit is the sign bit. The range is asymmetric — the minimum (−128) has no positive counterpart, since the maximum is only 127.
Literals
let a: int8 = -100; // explicit annotation
let b = 42i8; // type suffixIf a literal value does not fit in int8, the compiler emits an error at compile time. See Literals for decimal, hexadecimal, octal, and binary forms.
Typical Use Cases
- Small enumeration values and byte-ranged quantities
- Compact storage in large arrays and packed structures
- Delta values in compressed data formats
Arithmetic
| Operator | Description | Compound |
|---|---|---|
+ | Addition | += |
- | Subtraction | -= |
* | Multiplication | *= |
/ | Division | /= |
% | Remainder | %= |
** | Exponentiation | n/a |
let a: int8 = 10;
let b: int8 = 3;
let sum = a + b; // 13
let quot = a / b; // 3 truncates toward zero
let rem = a % b; // 1 carries the sign of the dividendDivision and remainder truncate toward zero, so the remainder takes the sign of the dividend: -7 % 2 is -1.
Overflow. In debug builds, signed overflow raises a fatal error. In release builds it wraps modulo 28 in two's-complement fashion. Wraparound is well-defined in Rux (unlike C/C++), but relying on it is almost always a logic error.
Comparison
| Operator | Description | Result |
|---|---|---|
== | Equal | bool |
!= | Not equal | bool |
< | Less than | bool |
<= | Less than or equal | bool |
> | Greater than | bool |
>= | Greater than or equal | bool |
Both operands must have the same type. Comparing int8 with another integer type — or with an unsigned type such as uint8 — is a compile-time error; cast one operand explicitly first.
Shift and Bitwise
Right shift on a signed value is arithmetic: vacated bits are filled with the sign bit, preserving the sign.
let s: int8 = -8; // 0b11111000
let r = s >> 2; // 0b11111110 = -2The bitwise operators &, |, ^, and ~ are also defined (~x equals −(x + 1)), but bitmask work usually reads more clearly on unsigned types.
Conversion
Rux performs no implicit numeric conversions — every conversion uses the as operator. Widening to a wider signed type preserves the value through sign extension; a same-width signed↔unsigned cast reinterprets the bit pattern.
let x: int8 = -1;
let wide = x as int32; // -1 sign-extended, value preserved
let u = x as uint8; // 255 same width, bits reinterpretedSee Also
uint8— unsigned counterpart of the same width- Unsigned Integer Types — the unsigned integer family