silk/i8

Eight-bit signed integers for compact values, byte-level formats, and narrow arithmetic.

When to use

Use i8 when an external format or data structure requires exactly eight signed bits. Prefer a wider integer for general arithmetic: the small range makes accidental overflow easy.

Ordinary arithmetic, narrowing conversions, division by zero, and invalid shift counts trap. Choose checked* when failure is data, wrapping* for arithmetic modulo 2^8, or saturating* when results should clamp to MIN or MAX. Signed right shifts preserve the sign bit.

Decimal parse consumes the complete input and distinguishes malformed text from a value outside the i8 range. toText allocates an owned decimal string.

Gotchas

MIN has no positive i8 counterpart, so ordinary negate traps for that one value.

Examples

Select the boundary policy for negation

import silk.i8 as i8

pub fn main() -> i32 {
  if i8.wrappingNegate(i8.MIN) != i8.MIN {
    return 1
  }
  if i8.saturatingNegate(i8.MIN) != i8.MAX {
    return 2
  }
  return 42
}

Import as i8 with import silk.i8.

Public declarations: 60.

`MAX`

pub const MAX: i8

The largest i8 value.

`MIN`

pub const MIN: i8

The smallest i8 value.

`BITS`

pub const BITS: u32

The fixed width of i8, in bits.

`negate`

pub fn negate(value: i8) -> i8

Returns the arithmetic negation of value and traps when value is MIN. Use this function when that boundary is a program error.

`wrappingNegate`

pub fn wrappingNegate(value: i8) -> i8

Returns the arithmetic negation of value, wrapped to the i8 range. MIN stays MIN. Use this function for deliberate modulo arithmetic.

`saturatingNegate`

pub fn saturatingNegate(value: i8) -> i8

Returns the arithmetic negation of value, clamped to the i8 range. MIN becomes MAX. Use this function when the positive boundary is required.

`toU8`

pub fn toU8(value: i8) -> u8

Converts value to u8. Traps if value is outside the u8 range. Use this function when an out-of-range value is a program error.

`checkedToU8`

pub fn checkedToU8(value: i8) -> Option<u8>

Converts value to u8, or returns None if value is outside the u8 range. Use this function when an out-of-range value is input data.

`toU16`

pub fn toU16(value: i8) -> u16

Converts value to u16. Traps if value is outside the u16 range. Use this function when an out-of-range value is a program error.

`checkedToU16`

pub fn checkedToU16(value: i8) -> Option<u16>

Converts value to u16, or returns None if value is outside the u16 range. Use this function when an out-of-range value is input data.

`toU32`

pub fn toU32(value: i8) -> u32

Converts value to u32. Traps if value is outside the u32 range. Use this function when an out-of-range value is a program error.

`checkedToU32`

pub fn checkedToU32(value: i8) -> Option<u32>

Converts value to u32, or returns None if value is outside the u32 range. Use this function when an out-of-range value is input data.

`toU64`

pub fn toU64(value: i8) -> u64

Converts value to u64. Traps if value is outside the u64 range. Use this function when an out-of-range value is a program error.

`checkedToU64`

pub fn checkedToU64(value: i8) -> Option<u64>

Converts value to u64, or returns None if value is outside the u64 range. Use this function when an out-of-range value is input data.

`toUsize`

pub fn toUsize(value: i8) -> usize

Converts value to usize. Traps if value is outside the usize range. Use this function when an out-of-range value is a program error.

`checkedToUsize`

pub fn checkedToUsize(value: i8) -> Option<usize>

Converts value to usize, or returns None if value is outside the usize range. Use this function when an out-of-range value is input data.

`toI8`

pub fn toI8(value: i8) -> i8

Returns value unchanged as i8. Use this function when generic conversion code can select i8 as both source and destination.

`checkedToI8`

pub fn checkedToI8(value: i8) -> Option<i8>

Returns Some with value unchanged as i8. Use this function when generic checked-conversion code can select the same source and destination type.

`toI16`

pub fn toI16(value: i8) -> i16

Converts value exactly to i16. Every i8 value is representable.

`checkedToI16`

pub fn checkedToI16(value: i8) -> Option<i16>

Converts value exactly to i16 and returns Some. Every i8 value is representable.

`toI32`

pub fn toI32(value: i8) -> i32

Converts value exactly to i32. Every i8 value is representable.

`checkedToI32`

pub fn checkedToI32(value: i8) -> Option<i32>

Converts value exactly to i32 and returns Some. Every i8 value is representable.

`toI64`

pub fn toI64(value: i8) -> i64

Converts value exactly to i64. Every i8 value is representable.

`checkedToI64`

pub fn checkedToI64(value: i8) -> Option<i64>

Converts value exactly to i64 and returns Some. Every i8 value is representable.

`toIsize`

pub fn toIsize(value: i8) -> isize

Converts value exactly to isize. Every i8 value is representable.

`checkedToIsize`

pub fn checkedToIsize(value: i8) -> Option<isize>

Converts value exactly to isize and returns Some. Every i8 value is representable.

`toF32`

pub fn toF32(value: i8) -> f32

Converts value to the nearest f32 value, with ties to even.

`toF64`

pub fn toF64(value: i8) -> f64

Converts value to the nearest f64 value, with ties to even.

`add`

pub fn add(left: i8, right: i8) -> i8

Returns left + right and traps if the result is outside the i8 range. Use this function when overflow is a program error.

`subtract`

pub fn subtract(left: i8, right: i8) -> i8

Returns left - right and traps if the result is outside the i8 range. Use this function when overflow is a program error.

`multiply`

pub fn multiply(left: i8, right: i8) -> i8

Returns left * right and traps if the result is outside the i8 range. Use this function when overflow is a program error.

`divide`

pub fn divide(left: i8, right: i8) -> i8

Returns left / right, rounded toward zero. Traps if right is zero or MIN is divided by -1. Use this function when an invalid quotient is a program error.

`remainder`

pub fn remainder(left: i8, right: i8) -> i8

Returns the remainder with the sign of left. Traps if right is zero or MIN is divided by -1. Use this function when invalid division is a program error.

`bitAnd`

pub fn bitAnd(left: i8, right: i8) -> i8

Returns the bitwise AND of left and right.

`bitOr`

pub fn bitOr(left: i8, right: i8) -> i8

Returns the bitwise OR of left and right.

`bitXor`

pub fn bitXor(left: i8, right: i8) -> i8

Returns the bitwise exclusive OR of left and right.

`bitNot`

pub fn bitNot(value: i8) -> i8

Returns value with each bit inverted.

`shiftLeft`

pub fn shiftLeft(left: i8, right: i8) -> i8

Shifts left bits left by right positions. Traps if right is negative or not less than BITS.

`shiftRight`

pub fn shiftRight(left: i8, right: i8) -> i8

Shifts left bits right by right positions and preserves its sign. Traps if right is negative or not less than BITS.

`rotateLeft`

pub fn rotateLeft(left: i8, right: i8) -> i8

Rotates the bits of left left by right positions.

`rotateRight`

pub fn rotateRight(left: i8, right: i8) -> i8

Rotates the bits of left right by right positions.

`wrappingAdd`

pub fn wrappingAdd(left: i8, right: i8) -> i8

Returns left + right, wrapped to the i8 range. Use this function for deliberate modulo arithmetic.

`wrappingSubtract`

pub fn wrappingSubtract(left: i8, right: i8) -> i8

Returns left - right, wrapped to the i8 range. Use this function for deliberate modulo arithmetic.

`wrappingMultiply`

pub fn wrappingMultiply(left: i8, right: i8) -> i8

Returns left * right, wrapped to the i8 range. Use this function for deliberate modulo arithmetic.

`saturatingAdd`

pub fn saturatingAdd(left: i8, right: i8) -> i8

Returns left + right, clamped to MIN or MAX. Use this function when a boundary value is the required overflow result.

`saturatingSubtract`

pub fn saturatingSubtract(left: i8, right: i8) -> i8

Returns left - right, clamped to MIN or MAX. Use this function when a boundary value is the required overflow result.

`saturatingMultiply`

pub fn saturatingMultiply(left: i8, right: i8) -> i8

Returns left * right, clamped to MIN or MAX. Use this function when a boundary value is the required overflow result.

`checkedAdd`

pub fn checkedAdd(left: i8, right: i8) -> Option<i8>

Returns Some with left + right, or None if the result is outside the i8 range. Use this function when overflow is input data.

`checkedSubtract`

pub fn checkedSubtract(left: i8, right: i8) -> Option<i8>

Returns Some with left - right, or None if the result is outside the i8 range. Use this function when overflow is input data.

`checkedMultiply`

pub fn checkedMultiply(left: i8, right: i8) -> Option<i8>

Returns Some with left * right, or None if the result is outside the i8 range. Use this function when overflow is input data.

`checkedDivide`

pub fn checkedDivide(left: i8, right: i8) -> Option<i8>

Returns Some with left / right, or None if right is zero or MIN is divided by -1. Use this function when an invalid quotient is input data.

`checkedRemainder`

pub fn checkedRemainder(left: i8, right: i8) -> Option<i8>

Returns Some with the remainder, or None if right is zero or MIN is divided by -1. Use this function when invalid division is input data.

`equals`

pub fn equals(left: i8, right: i8) -> bool

Returns true when left and right are equal.

`notEquals`

pub fn notEquals(left: i8, right: i8) -> bool

Returns true when left and right are not equal.

`lessThan`

pub fn lessThan(left: i8, right: i8) -> bool

Returns true when left is less than right.

`lessOrEqual`

pub fn lessOrEqual(left: i8, right: i8) -> bool

Returns true when left is less than or equal to right.

`greaterThan`

pub fn greaterThan(left: i8, right: i8) -> bool

Returns true when left is greater than right.

`greaterOrEqual`

pub fn greaterOrEqual(left: i8, right: i8) -> bool

Returns true when left is greater than or equal to right.

`toText`

pub effect fn toText(value: i8) -> String ! OutOfMemoryError ? &mut Allocator

Renders the value as base-10 text in new owned storage. Allocation uses the required Allocator and can fail with OutOfMemoryError.

`parse`

pub fn parse(text: string) -> silk/result.Result<i8, silk/format.ParseError>

Reads the complete text as a signed decimal i8.

Details

A failure contains silk.format.NotANumber for empty text, a leading +, a non-digit, or trailing bytes. It contains silk.format.OutOfRange if the number is outside the i8 range.

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