Struct ConstantData

pub struct ConstantData(/* private fields */);

This type describes the actual constant data. Note that the bytes stored in this structure are expected to be in little-endian order; this is due to ease-of-use when interacting with WebAssembly values, which are little-endian by design.

Implementations

impl ConstantData

pub fn len(&self) -> usize

Return the number of bytes in the constant.

pub fn is_empty(&self) -> bool

Check if the constant contains any bytes.

pub fn as_slice(&self) -> &[u8]

Return the data as a slice.

pub fn into_vec(self) -> Vec<u8>

Convert the data to a vector.

pub fn iter(&self) -> Iter<'_, u8>

Iterate over the constant’s bytes.

pub fn append(self, bytes: impl IntoBytes) -> Self

Add new bytes to the constant data.

pub fn expand_to(self, expected_size: usize) -> Self

Expand the size of the constant data to expected_size number of bytes by adding zeroes in the high-order byte slots.

Trait Implementations

impl Clone for ConstantData

fn clone(&self) -> ConstantData

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ConstantData

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

Formats the value using the given formatter.

impl Default for ConstantData

fn default() -> ConstantData

Returns the “default value” for a type.

impl Display for ConstantData

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

Print the constant data in hexadecimal format, e.g. 0x000102030405060708090a0b0c0d0e0f. This function will flip the stored order of bytes–little-endian–to the more readable big-endian ordering.

use cranelift_codegen::ir::ConstantData;
let data = ConstantData::from([3, 2, 1, 0, 0].as_ref()); // note the little-endian order
assert_eq!(data.to_string(), "0x0000010203");

impl From<&[u8]> for ConstantData

fn from(v: &[u8]) -> Self

Converts to this type from the input type.

impl From<Ieee128> for ConstantData

fn from(v: Ieee128) -> Self

Converts to this type from the input type.

impl From<V128Imm> for ConstantData

fn from(v: V128Imm) -> Self

Converts to this type from the input type.

impl From<Vec<u8>> for ConstantData

fn from(v: Vec<u8>) -> Self

Converts to this type from the input type.

impl FromIterator<u8> for ConstantData

fn from_iter<T: IntoIterator<Item = u8>>(iter: T) -> Self

Creates a value from an iterator.

impl FromStr for ConstantData

fn from_str(s: &str) -> Result<Self, &'static str>

Parse a hexadecimal string to ConstantData. This is the inverse of Display::fmt.

use cranelift_codegen::ir::ConstantData;
let c: ConstantData = "0x000102".parse().unwrap();
assert_eq!(c.into_vec(), [2, 1, 0]);

type Err = &'static str

The associated error which can be returned from parsing.

impl Hash for ConstantData

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 Ord for ConstantData

fn cmp(&self, other: &ConstantData) -> 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,

Restrict a value to a certain interval.

impl PartialEq for ConstantData

fn eq(&self, other: &ConstantData) -> 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 ConstantData

fn partial_cmp(&self, other: &ConstantData) -> 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 TryFrom<&ConstantData> for Ieee128

type Error = <[u8; 16] as TryFrom<&'static [u8]>>::Error

The type returned in the event of a conversion error.

fn try_from(value: &ConstantData) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for ConstantData

impl StructuralPartialEq for ConstantData