Struct Span

pub struct Span { /* private fields */ }

A span over a &str. It is created from either two Positions or from a Pair.

Implementations

impl Span

pub fn input(&self) -> &Arc<str>

Get the original input that this Span refers to without being indexed from start to end.

pub unsafe fn new_unchecked(input: Arc<str>, start: usize, end: usize) -> Span

Create a new Span without checking invariants. (Checked with debug_assertions.)

Safety

input[start..end] must be a valid subslice; that is, said indexing should not panic.

pub fn new(input: Arc<str>, start: usize, end: usize) -> Option<Span>

Attempts to create a new span. Will return None if input[start..end] is an invalid index into input.

Examples

let input: Arc<str> = Arc::from("Hello!");
assert_eq!(None, Span::new(input.clone(), 100, 0));
assert!(Span::new(input.clone(), 0, input.len()).is_some());

pub fn start(&self) -> usize

Returns the Span’s start byte position as a usize.

Examples

let input: Arc<str> = Arc::from("ab");
let start = Position::from_start(input);
let end = start.clone();
let span = start.span(&end);

assert_eq!(span.start(), 0);

pub fn end(&self) -> usize

Returns the Span’s end byte position as a usize.

Examples

let input: Arc<str> = Arc::from("ab");
let start = Position::from_start(input);
let end = start.clone();
let span = start.span(&end);

assert_eq!(span.end(), 0);

pub fn start_pos(&self) -> Position

Returns the Span’s start Position.

Examples

let input: Arc<str> = Arc::from("ab");
let start = Position::from_start(input);
let end = start.clone();
let span = start.clone().span(&end);

assert_eq!(span.start_pos(), start);

pub fn end_pos(&self) -> Position

Returns the Span’s end Position.

Examples

let input: Arc<str> = Arc::from("ab");
let start = Position::from_start(input);
let end = start.clone();
let span = start.span(&end);

assert_eq!(span.end_pos(), end);

pub fn split(self) -> (Position, Position)

Splits the Span into a pair of Positions.

Examples

let input: Arc<str> = Arc::from("ab");
let start = Position::from_start(input);
let end = start.clone();
let span = start.clone().span(&end);

assert_eq!(span.split(), (start, end));

pub fn as_str(&self) -> &str

Captures a slice from the &str defined by the Span.

Examples

enum Rule {}

let input: Arc<str> = Arc::from("abc");
let mut state: Box<pest::ParserState<Rule>> = pest::ParserState::new(input).skip(1).unwrap();
let start_pos = state.position().clone();
state = state.match_string("b").unwrap();
let span = start_pos.span(&state.position().clone());
assert_eq!(span.as_str(), "b");

pub fn lines(&self) -> Lines<'_>

Iterates over all lines (partially) covered by this span.

Examples

enum Rule {}

let input: Arc<str> = Arc::from("a\nb\nc");
let mut state: Box<pest::ParserState<Rule>> = pest::ParserState::new(input).skip(2).unwrap();
let start_pos = state.position().clone();
state = state.match_string("b\nc").unwrap();
let span = start_pos.span(&state.position().clone());
assert_eq!(span.lines().collect::<Vec<_>>(), vec!["b\n", "c"]);

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 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 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 Eq for Span