Struct Span 

pub struct Span { /* private fields */ }

References a range of bytes in the original source file.

Can be missing, in which case doesn’t correspond to any actual portion of the source file. This is the Default value.

For the purposes of comparisons, all spans are considered equal to each other. This means that calling PartialEq::eq just returns true, calling Hash::hash does nothing and calling Ord::cmp always returns Ordering::Equal. This means that adding a Span field to a type can never impact the derived implementations of these traits.

Implementations

impl Span

pub const MISSING: Span

Indicates that the span information is missing, and doesn’t correspond to a known portion of the source file.

pub fn new(start: Location, end: Location) -> Span

Create a span with the specified start and end locations.

If either location is missing, this will return Span::MISSING.

Panics

If the start location comes after the end location, this function will panic. If either location is missing, this function is guaranteed to succeed.

pub fn from_byte_range<T: PrimUInt>(range: Range<T>) -> Self

Create a span from the specified range of byte indexes.

Panics

This will panic if the start location comes after the end location, just like Span::new. This will also panic if either offset overflows a Location, just like Location::from_byte.

pub fn eq(self) -> OrderedSpan

Return a wrapper type that implements by-value equality rather than having all values be equal.

pub fn ord(self) -> OrderedSpan

Return a wrapper type that implements by-value ordering rather than having all values be equal.

pub const fn is_missing(&self) -> bool

Check if the span is Self::MISSING.

pub fn byte_range(&self) -> Result<Range<u64>, MissingLocationError>

Return the range of bytes in the original file, or a MissingLocationError if missing.

pub fn byte_len(&self) -> Result<u64, MissingLocationError>

Returns the length of the span in bytes, or a MissingLocationError if missing.

pub fn slice_byte_indexes<R>(self, range: R) -> Self

where R: RangeBounds<u64> + Debug,

Slice the bytes indices this span, returning a subset of its indexes.

If the original span is missing, the result will be too.

Panics

Referencing an index that exceeds the byte length of this span will trigger a panic. This will also panic If the start of the range exceeds the end of the range,

Examples

use qbe_parser::ast::Span;
let x = Span::from_byte_range::<u32>(5..20);
assert_eq!(
    x.slice_byte_indexes(2..).byte_range(),
    Ok(7..20)
);
assert_eq!(
    x.slice_byte_indexes(3..5).byte_range(),
    Ok(8..10)
);
assert_eq!(
    x.slice_byte_indexes(3..=5).byte_range(),
    Ok(8..11)
);

The following code will panic due to referencing an out-of-bounds indexes.

use qbe_parser::ast::Span;
let x = Span::from_byte_range::<u32>(5..20);
assert_eq!(x.byte_len(), Ok(15));
x.slice_byte_indexes(100..); // panics

pub fn start(&self) -> Location

The starting location of the span (inclusive), or Location::MISSING if missing.

pub fn end(&self) -> Location

The ending location of the span (exclusive), or Location::MISSING if missing.

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Span

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

Formats the value using the given formatter.

impl Default for Span

fn default() -> Self

Returns the “default value” for a type.

impl Display for Span

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

Formats the value using the given formatter.

impl From<ByteLocation> for Span

fn from(location: ByteLocation) -> Self

Converts to this type from the input type.

impl From<Location> for Span

fn from(value: Location) -> Self

Converts to this type from the input type.

impl From<OrderedSpan> for Span

fn from(value: OrderedSpan) -> Self

Converts to this type from the input type.

impl From<SimpleSpan> for Span

fn from(span: SimpleSpan) -> Self

Converts to this type from the input type.

impl From<Span> for OrderedSpan

fn from(span: Span) -> Self

Converts to this type from the input type.

impl Hash for Span

Hashes the span.

This is guaranteed to do nothing, so adding it to a struct will not affect the result of derive(Hash).

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 Span

fn cmp(&self, _other: &Self) -> 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<Span> for OrderedSpan

fn eq(&self, other: &Span) -> 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 PartialEq for Span

Unconditionally returns true, so that adding a Span to a struct will not affect derive(Eq)

fn eq(&self, _other: &Span) -> 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<Span> for OrderedSpan

fn partial_cmp(&self, other: &Span) -> 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 PartialOrd for Span

fn partial_cmp(&self, other: &Self) -> 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 Span for Span

type Context = ()

Extra context used in a span.

type Offset = ByteLocation

A type representing a span’s start or end offset from the start of the input.

fn new(_context: Self::Context, range: Range<Self::Offset>) -> Self

Create a new span given a context and an offset range.

fn context(&self) -> Self::Context

Return the span’s context.

fn start(&self) -> Self::Offset

Return the start offset of the span.

fn end(&self) -> Self::Offset

Return the end offset of the span.

fn to_end(&self) -> Self

where Self: Sized,

Turn this span into a zero-width span that starts and ends at the end of the original.

impl Copy for Span

impl Eq for Span