Struct BytePos 

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

A zero-based byte offset into a single source buffer.

BytePos is a Copy newtype over a u32, so it is eight-times cheaper to move than a usize pair and fits two-to-a-cache-line inside a Span. The 32-bit width bounds a single source to 4 GiB, which is the addressing envelope language front-ends use; a larger source belongs in a multi-file mapping above this crate, not in a wider offset here.

The offset is a byte index, not a character index — it may only legally fall on a UTF-8 character boundary. Resolving an offset that lands inside a multi-byte sequence is defined (it rounds down) rather than undefined; see LineIndex::line_col.

Examples

use span_lang::BytePos;

let p = BytePos::new(42);
assert_eq!(p.to_u32(), 42);
assert_eq!(p.to_usize(), 42);

// Ordered, so positions sort and compare naturally.
assert!(BytePos::new(1) < BytePos::new(2));

Implementations

impl BytePos

pub const fn new(offset: u32) -> Self

Constructs a position from a raw byte offset.

Examples

use span_lang::BytePos;

const START: BytePos = BytePos::new(0);
assert_eq!(START.to_u32(), 0);

pub const fn to_u32(self) -> u32

Returns the raw byte offset.

Examples

use span_lang::BytePos;

assert_eq!(BytePos::new(7).to_u32(), 7);

pub const fn to_usize(self) -> usize

Returns the offset widened to a usize, ready to index a byte slice.

Examples

use span_lang::BytePos;

let src = b"hello";
let at = BytePos::new(1);
assert_eq!(src[at.to_usize()], b'e');

Trait Implementations

impl Clone for BytePos

fn clone(&self) -> BytePos

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BytePos

impl Debug for BytePos

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

Formats the value using the given formatter.

impl Default for BytePos

fn default() -> BytePos

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for BytePos

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for BytePos

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

Formats the value using the given formatter.

impl Eq for BytePos

impl From<BytePos> for u32

fn from(pos: BytePos) -> Self

Converts to this type from the input type.

impl From<u32> for BytePos

fn from(offset: u32) -> Self

Converts to this type from the input type.

impl Hash for BytePos

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 BytePos

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

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

fn partial_cmp(&self, other: &BytePos) -> 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 Serialize for BytePos

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for BytePos