Struct pest::Span

pub struct Span<'i> { /* fields omitted */ }

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

Methods

impl<'i> Span<'i>

pub fn new(input: &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 = "Hello!";
assert_eq!(None, Span::new(input, 100, 0));
assert!(Span::new(input, 0, input.len()).is_some());

pub fn start(&self) -> usize

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

Examples

let input = "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 = "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<'i>

Returns the Span's start Position.

Examples

let input = "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<'i>

Returns the Span's end Position.

Examples

let input = "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<'i>, Position<'i>)

Splits the Span into a pair of Positions.

Examples

let input = "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) -> &'i str

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

Examples

enum Rule {}

let input = "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");

Important traits for Lines<'i>

impl<'i> Iterator for Lines<'i> type Item = &'i str;

pub fn lines(&self) -> Lines

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

Examples

enum Rule {}

let input = "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<'i> Clone for Span<'i>

fn clone(&self) -> Span<'i>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'i> Eq for Span<'i>

impl<'i> PartialEq<Span<'i>> for Span<'i>

fn eq(&self, other: &Span<'i>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'i> Debug for Span<'i>

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

Formats the value using the given formatter.

impl<'i> Hash for Span<'i>

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, 

Feeds a slice of this type into the given [Hasher].