silk/u64

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. toText allocates owned text. Conversion to a floating type may 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 as u64

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

Import as u64 with import silk.u64.

Public declarations: 57.

`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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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) -> 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.

`toText`

pub effect fn toText(value: u64) -> 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<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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