Struct core::Scaled

pub struct Scaled(pub i32);

Scaled numbers.

This is a fixed-width numeric type used in throughout TeX. This type is defined and described in part 7 “arithmetic with scaled dimensions” starting at TeX.2021.99.

This numeric type has 15 bits for the integer part, 16 bits for the fractional part, and a single signed bit. The inner value is the number multiplied by 2^16.

Tuple Fields

0: i32

Implementations

impl Scaled

pub const ZERO: Scaled = _

Representation of the number 0 as a Scaled.

pub const ONE: Scaled = _

Representation of the number 1 as a Scaled.

pub const TWO: Scaled = _

Representation of the number 2 as a Scaled.

pub const MAX_DIMEN: Scaled = _

Maximum possible dimension in TeX, which is (2^30-1)/2^16.

This is not the maximum size of the Rust scaled number type, which is (2^31-1)/2^16.

Defined in TeX.2021.421.

pub fn from_integer(i: i32) -> Result<Scaled, OverflowError>

Create a scaled number corresponding the provided positive integer.

Scaled numbers are in the range (-2^14, 2^14). If i is outside this range an overflow error is returned.

pub fn from_decimal_digits(digits: &[u8]) -> Scaled

Creates a scaled number from a decimal fraction.

TeX.2021.102.

pub fn new( integer_part: i32, fractional_part: Scaled, scaled_unit: ScaledUnit, ) -> Result<Scaled, OverflowError>

Creates a scaled number from the provided components.

TeX.2021.458

pub fn xn_over_d( &self, n: i32, d: i32, ) -> Result<(Scaled, Scaled), OverflowError>

Calculates the integer division xn/d and remainder, where x is this scaled number and n and d are integers in the range [0,2^16].

This function appears in TeX.2021.107. Knuth is working with 32-bit integers and so calculating this number is tricky without overflowing. E.g. xn may be larger than 2^32-1 even if the final result is in range. TeX has an algorithm that calculates the exact value without overflowing, in the case when the final result is in range.

Our implementation simply uses 64-bit integers.

pub fn nx_plus_y(self, n: i32, y: Scaled) -> Result<Scaled, OverflowError>

TeX.2021.105

pub fn integer_part(self) -> i32

pub fn fractional_part(self) -> Scaled

pub fn abs(self) -> Scaled

pub fn wrapping_add(self, rhs: Scaled) -> Self

pub fn checked_add(self, rhs: Scaled) -> Option<Self>

pub fn wrapping_mul(self, rhs: i32) -> Self

pub fn checked_mul(self, rhs: i32) -> Option<Self>

pub fn checked_div(self, rhs: i32) -> Option<Self>

pub fn display_no_units(self) -> impl Display

Trait Implementations

impl Add for Scaled

type Output = Scaled

The resulting type after applying the + operator.

fn add(self, rhs: Scaled) -> Self::Output

Performs the + operation.

impl Clone for Scaled

fn clone(&self) -> Scaled

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Scaled

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Scaled

fn default() -> Scaled

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Scaled

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Scaled

fn fmt(&self, fm: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Div<i32> for Scaled

type Output = Scaled

The resulting type after applying the / operator.

fn div(self, rhs: i32) -> Self::Output

Performs the / operation.

impl Hash for Scaled

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Mul<i32> for Scaled

type Output = Scaled

The resulting type after applying the * operator.

fn mul(self, rhs: i32) -> Self::Output

Performs the * operation.

impl Neg for Scaled

type Output = Scaled

The resulting type after applying the - operator.

fn neg(self) -> Self::Output

Performs the unary - operation.

impl Ord for Scaled

fn cmp(&self, other: &Scaled) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Scaled

fn eq(&self, other: &Scaled) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Scaled

fn partial_cmp(&self, other: &Scaled) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Rem<i32> for Scaled

type Output = Scaled

The resulting type after applying the % operator.

fn rem(self, rhs: i32) -> Self::Output

Performs the % operation.

impl Serialize for Scaled

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Sub for Scaled

type Output = Scaled

The resulting type after applying the - operator.

fn sub(self, rhs: Scaled) -> Self::Output

Performs the - operation.

impl Copy for Scaled

impl Eq for Scaled

impl StructuralPartialEq for Scaled