Struct Position 

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

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

Implementations

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.

This is an O(n) operation, where n is the number of chars in the input. You better use pair.line_col() instead.

Panics

Panics if the position is out of bounds.

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.

Panics

Panics if the position is out of bounds (e.g., beyond the end of the input).

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 duplicate of the value.

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

Performs copy-assignment from source.

impl<'i> Copy for Position<'i>

impl Debug for Position<'_>

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

Formats the value using the given formatter.

impl Eq for Position<'_>

impl From<Position<'_>> for LineColLocation

fn from(value: Position<'_>) -> Self

Converts to this type from the input type.

impl Hash for Position<'_>

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<'i> Ord for Position<'i>

Panics

Panics when comparing positions from different input strings.

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

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

Equality operator ==.

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

Inequality operator !=.

impl<'i> PartialOrd 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.

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.