silk/u64

Profiles: aarch64-apple-darwin, aarch64-unknown-linux-gnu, aarch64-unknown-linux-gnu-no-libc, wasm32-unknown-unknown, x86_64-unknown-linux-gnu, x86_64-unknown-linux-gnu-no-libc.

Sixty-four-bit unsigned integers for wide masks, counters, hashes, and exact interchange values.

When to use

Use u64 when a stable unsigned 64-bit representation matters. It is the representation used for hash output; use usize instead for target-sized collection lengths and indices.

Ordinary arithmetic, narrowing conversions, division by zero, and invalid shift counts trap. checked* returns Option, wrapping* computes modulo 2^64, and saturating* clamps at MIN or MAX. Right shift inserts zero bits.

Decimal parse consumes the complete input and separates malformed text from range overflow. Use Format with Format.display for defaults or Format.displayWith for explicit options. Both operations stream through a mutable Writer without Allocator. Conversion to a floating type can round large values.

Gotchas

A u64 can represent values that neither i64 nor every target's usize can hold; use a checked conversion when that boundary is controlled by input.

Examples

Read the high half of a 64-bit field

import silk.u64

pub fn main() -> i32 {
  let high = u64.shiftRight(0x0000002A00000000, 32)
  return u64.toI32(high)
}

Import as u64 with import silk.u64.

Public declarations: 56.

`MAX`

pub const MAX: u64

The largest u64 value.

`MIN`

pub const MIN: u64

The smallest u64 value.

`BITS`

pub const BITS: u32

The fixed width of u64, in bits.

`toU8`

pub fn toU8(value: u64) -> 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: u64) -> silk/option.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: u64) -> 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: u64) -> silk/option.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: u64) -> 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: u64) -> silk/option.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: u64) -> u64

Returns value unchanged as u64. Use this function when generic conversion code can select u64 as both source and destination.

`checkedToU64`

pub fn checkedToU64(value: u64) -> silk/option.Option<u64>

Returns Some with value unchanged as u64. Use this function when generic checked-conversion code can select the same source and destination type.

`toUsize`

pub fn toUsize(value: u64) -> 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: u64) -> silk/option.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: u64) -> i8

Converts value to i8. Traps if value is outside the i8 range. Use this function when an out-of-range value is a program error.

`checkedToI8`

pub fn checkedToI8(value: u64) -> silk/option.Option<i8>

Converts value to i8, or returns None if value is outside the i8 range. Use this function when an out-of-range value is input data.

`toI16`

pub fn toI16(value: u64) -> i16

Converts value to i16. Traps if value is outside the i16 range. Use this function when an out-of-range value is a program error.

`checkedToI16`

pub fn checkedToI16(value: u64) -> silk/option.Option<i16>

Converts value to i16, or returns None if value is outside the i16 range. Use this function when an out-of-range value is input data.

`toI32`

pub fn toI32(value: u64) -> i32

Converts value to i32. Traps if value is outside the i32 range. Use this function when an out-of-range value is a program error.

`checkedToI32`

pub fn checkedToI32(value: u64) -> silk/option.Option<i32>

Converts value to i32, or returns None if value is outside the i32 range. Use this function when an out-of-range value is input data.

`toI64`

pub fn toI64(value: u64) -> i64

Converts value to i64. Traps if value is outside the i64 range. Use this function when an out-of-range value is a program error.

`checkedToI64`

pub fn checkedToI64(value: u64) -> silk/option.Option<i64>

Converts value to i64, or returns None if value is outside the i64 range. Use this function when an out-of-range value is input data.

`toIsize`

pub fn toIsize(value: u64) -> isize

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

`checkedToIsize`

pub fn checkedToIsize(value: u64) -> silk/option.Option<isize>

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

`toF32`

pub fn toF32(value: u64) -> f32

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

`toF64`

pub fn toF64(value: u64) -> f64

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

`add`

pub fn add(left: u64, right: u64) -> u64

Returns left + right and traps if the result is outside the u64 range. Use this function when overflow is a program error.

`subtract`

pub fn subtract(left: u64, right: u64) -> u64

Returns left - right and traps if the result is outside the u64 range. Use this function when overflow is a program error.

`multiply`

pub fn multiply(left: u64, right: u64) -> u64

Returns left * right and traps if the result is outside the u64 range. Use this function when overflow is a program error.

`divide`

pub fn divide(left: u64, right: u64) -> u64

Returns left / right. Traps if right is zero. Use this function when a zero divisor is a program error.

`remainder`

pub fn remainder(left: u64, right: u64) -> u64

Returns the remainder of left / right. Traps if right is zero. Use this function when a zero divisor is a program error.

`bitAnd`

pub fn bitAnd(left: u64, right: u64) -> u64

Returns the bitwise AND of left and right.

`bitOr`

pub fn bitOr(left: u64, right: u64) -> u64

Returns the bitwise OR of left and right.

`bitXor`

pub fn bitXor(left: u64, right: u64) -> u64

Returns the bitwise exclusive OR of left and right.

`bitNot`

pub fn bitNot(value: u64) -> u64

Returns value with each bit inverted.

`shiftLeft`

pub fn shiftLeft(left: u64, right: u64) -> u64

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

`shiftRight`

pub fn shiftRight(left: u64, right: u64) -> u64

Shifts left bits right by right positions and inserts zero bits. Traps if right is not less than BITS.

`rotateLeft`

pub fn rotateLeft(left: u64, right: u64) -> u64

Rotates the bits of left left by right positions.

`rotateRight`

pub fn rotateRight(left: u64, right: u64) -> u64

Rotates the bits of left right by right positions.

`wrappingAdd`

pub fn wrappingAdd(left: u64, right: u64) -> u64

Returns left + right, wrapped to the u64 range. Use this function for deliberate modulo arithmetic.

`wrappingSubtract`

pub fn wrappingSubtract(left: u64, right: u64) -> u64

Returns left - right, wrapped to the u64 range. Use this function for deliberate modulo arithmetic.

`wrappingMultiply`

pub fn wrappingMultiply(left: u64, right: u64) -> u64

Returns left * right, wrapped to the u64 range. Use this function for deliberate modulo arithmetic.

`saturatingAdd`

pub fn saturatingAdd(left: u64, right: u64) -> u64

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: u64, right: u64) -> u64

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: u64, right: u64) -> u64

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: u64, right: u64) -> silk/option.Option<u64>

Returns Some with left + right, or None if the result is outside the u64 range. Use this function when overflow is input data.

`checkedSubtract`

pub fn checkedSubtract(left: u64, right: u64) -> silk/option.Option<u64>

Returns Some with left - right, or None if the result is outside the u64 range. Use this function when overflow is input data.

`checkedMultiply`

pub fn checkedMultiply(left: u64, right: u64) -> silk/option.Option<u64>

Returns Some with left * right, or None if the result is outside the u64 range. Use this function when overflow is input data.

`checkedDivide`

pub fn checkedDivide(left: u64, right: u64) -> silk/option.Option<u64>

Returns Some with left / right, or None if right is zero. Use this function when a zero divisor is input data.

`checkedRemainder`

pub fn checkedRemainder(left: u64, right: u64) -> silk/option.Option<u64>

Returns Some with the remainder, or None if right is zero. Use this function when a zero divisor is input data.

`equals`

pub fn equals(left: u64, right: u64) -> bool

Returns true when left and right are equal.

`notEquals`

pub fn notEquals(left: u64, right: u64) -> bool

Returns true when left and right are not equal.

`lessThan`

pub fn lessThan(left: u64, right: u64) -> bool

Returns true when left is less than right.

`lessOrEqual`

pub fn lessOrEqual(left: u64, right: u64) -> bool

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

`greaterThan`

pub fn greaterThan(left: u64, right: u64) -> bool

Returns true when left is greater than right.

`greaterOrEqual`

pub fn greaterOrEqual(left: u64, right: u64) -> bool

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

`parse`

pub fn parse<'life0>(text: string<'life0>) -> silk/result.Result<u64, silk/format.ParseError>

Reads the complete text as an unsigned decimal u64.

Details

A failure contains silk.format.NotANumber for empty text, a sign, a non-digit, or trailing bytes. It contains silk.format.OutOfRange if the number is outside the u64 range.

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