Struct pest::Position

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

A cursor position in a &str which provides useful methods to manually parse that string.

Methods

impl<'i> Position<'i>

pub fn new(input: &str, pos: usize) -> Option<Position>

Attempts to create a new Position at the given position. If the specified position is an invalid index, or the specified position is not a valid UTF8 boundary, then None is returned.

Examples

let cheart = '💖';
let heart = "💖";
assert_eq!(Position::new(heart, 1), None);
assert_ne!(Position::new(heart, cheart.len_utf8()), None);

pub fn from_start(input: &'i str) -> Position<'i>

Creates a Position at the start of a &str.

Examples

let start = Position::from_start("");
assert_eq!(start.pos(), 0);

pub fn pos(&self) -> usize

Returns the byte position of this Position as a usize.

Examples

let input = "ab";
let mut start = Position::from_start(input);

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

pub fn span(&self, other: &Position<'i>) -> Span<'i>

Creates a Span from two Positions.

Panics

Panics if the positions come from different inputs.

Examples

let input = "ab";
let start = Position::from_start(input);
let span = start.span(&start.clone());

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

pub fn line_col(&self) -> (usize, usize)

Returns the line and column number of this Position.

Examples

enum Rule {}

let input = "\na";
let mut state: Box<pest::ParserState<Rule>> = pest::ParserState::new(input);
let mut result = state.match_string("\na");
assert!(result.is_ok());
assert_eq!(result.unwrap().position().line_col(), (2, 2));

pub fn line_of(&self) -> &'i str

Returns the entire line of the input that contains this Position.

Examples

enum Rule {}

let input = "\na";
let mut state: Box<pest::ParserState<Rule>> = pest::ParserState::new(input);
let mut result = state.match_string("\na");
assert!(result.is_ok());
assert_eq!(result.unwrap().position().line_of(), "a");

Trait Implementations

impl<'i> Clone for Position<'i>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'i> Ord for Position<'i>

fn cmp(&self, other: &Position<'i>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<'i> Eq for Position<'i>

impl<'i> PartialOrd<Position<'i>> for Position<'i>

fn partial_cmp(&self, other: &Position<'i>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

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

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

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

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'i> PartialEq<Position<'i>> for Position<'i>

fn eq(&self, other: &Position<'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 Position<'i>

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

Formats the value using the given formatter.

impl<'i> Hash for Position<'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].