Struct Span

pub struct Span {
    pub lo: BytePos,
    pub hi: BytePos,
    pub ctxt: SyntaxContext,
}

Spans represent a region of code, used for error reporting. Positions in spans are absolute positions from the beginning of the codemap, not positions relative to FileMaps. Methods on the CodeMap can be used to relate spans back to the original source. You must be careful if the span crosses more than one file - you will not be able to use many of the functions on spans in codemap and you cannot assume that the length of the span = hi - lo; there may be space in the BytePos range between files.

Fields

lo: BytePos

hi: BytePos

ctxt: SyntaxContext

Information about where the macro came from, if this piece of code was created by a macro expansion.

Implementations

impl Span

pub fn end_point(self) -> Span

Returns a new span representing just the end-point of this span

pub fn next_point(self) -> Span

Returns a new span representing the next character after the end-point of this span

pub fn substitute_dummy(self, other: Span) -> Span

Returns self if self is not the dummy span, and other otherwise.

pub fn contains(self, other: Span) -> bool

pub fn source_equal(&self, other: &Span) -> bool

Return true if the spans are equal with regards to the source text.

Use this instead of == when either span could be generated code, and you only care that they point to the same bytes of source text.

pub fn trim_start(self, other: Span) -> Option<Span>

Returns Some(span), where the start is trimmed by the end of other

pub fn source_callsite(self) -> Span

Return the source span - this is either the supplied span, or the span for the macro callsite that expanded to it.

pub fn source_callee(self) -> Option<NameAndSpan>

Return the source callee.

Returns None if the supplied span has no expansion trace, else returns the NameAndSpan for the macro definition corresponding to the source callsite.

pub fn allows_unstable(&self) -> bool

Check if a span is “internal” to a macro in which #[unstable] items can be used (that is, a macro marked with #[allow_internal_unstable]).

pub fn macro_backtrace(self) -> Vec<MacroBacktrace>

pub fn to(self, end: Span) -> Span

pub fn between(self, end: Span) -> Span

pub fn until(self, end: Span) -> Span

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a copy 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<'de> Deserialize<'de> for Span

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<Span> for MultiSpan

fn from(span: Span) -> MultiSpan

Converts to this type from the input type.

impl Hash for Span

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: &Span) -> 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 Span

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 for Span

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 Serialize for Span

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Span

impl Eq for Span

impl StructuralPartialEq for Span