Struct luaparse::InputCursor

pub struct InputCursor<'a> { /* fields omitted */ }

An input cursor.

Implementations

impl<'a> InputCursor<'a>

pub fn new(buf: &'a str) -> Self

Create a new cursor from a buffer.

pub fn peek_nth(&self, n: usize) -> Option<char>

Returns the nth character after the cursor without advancing the cursor.

let cursor = InputCursor::new("hello world!");
assert_eq!(cursor.peek_nth(0), Some('h'));
assert_eq!(cursor.peek_nth(2), Some('l'));

pub fn peek(&self) -> Option<char>

Returns the next character without advancing the cursor. Equivalent to peek_nth(0).

let cursor = InputCursor::new("hello world!");
assert_eq!(cursor.peek(), Some('h'));
assert_eq!(cursor.peek(), cursor.peek_nth(0));

pub fn pos(&self) -> Position

Returns the position of the following character.

let mut cursor = InputCursor::new("hello\nworld");
assert_eq!(cursor.pos(), Position {
    byte: 0,
    line: 1,
    col: 1,
});
cursor.skip_n(5);
assert_eq!(cursor.pos(), Position {
    byte: 5,
    line: 1,
    col: 6,
});
cursor.next();
assert_eq!(cursor.pos(), Position {
    byte: 6,
    line: 2,
    col: 1,
});

pub fn pos_no_newline(&self) -> Position

Returns the position of the following character.

Only differs from pos when the cursor is immediately after a newline character. In that case, unlike pos, this method does not go to the next line.

let mut cursor = InputCursor::new("hello\nworld");
assert_eq!(cursor.pos(), Position {
    byte: 0,
    line: 1,
    col: 1,
});
cursor.skip_n(5);
assert_eq!(cursor.pos(), Position {
    byte: 5,
    line: 1,
    col: 6,
});
cursor.next();
assert_eq!(cursor.pos(), Position {
    byte: 6,
    line: 1,
    col: 7,
});

pub fn prev_pos(&self) -> Position

Returns the position of the preceding character.

let mut cursor = InputCursor::new("hello\nworld");
assert_eq!(cursor.prev_pos(), Position {
    byte: 0,
    line: 1,
    col: 1,
});
cursor.skip_n(5);
assert_eq!(cursor.prev_pos(), Position {
    byte: 4,
    line: 1,
    col: 5,
});
cursor.next();
assert_eq!(cursor.prev_pos(), Position {
    byte: 5,
    line: 1,
    col: 6,
});

pub fn remaining(&self) -> &'a str

Returns the remaining string as a subslice.

let mut cursor = InputCursor::new("hello world");
cursor.skip_n(6);
assert_eq!(cursor.remaining(), "world");

pub fn substr<I>(&self, range: I) -> &'a str where
    I: RangeBounds<Position>, 

Returns a substring of the buffer.

Accepts a range defined by two Positions.

The positions must be previously obtained using pos or its variant. The function may panic if the position is invalid.

let mut cursor = InputCursor::new("hello world!");
let start = cursor.pos();
cursor.skip_n(5);
let end = cursor.prev_pos();
assert_eq!(cursor.substr(start..=end), "hello");

pub fn skip_n(&mut self, n: usize)

Advances the cursor by n characters.

let mut cursor = InputCursor::new("hello world!");
cursor.skip_n(6);
assert_eq!(cursor.remaining(), "world!");

pub fn consume_n(&mut self, n: usize) -> &'a str

Consumes n characters starting from the current position.

let mut cursor = InputCursor::new("hello world!");
let s = cursor.consume_n(5);
assert_eq!(s, "hello");
assert_eq!(cursor.remaining(), " world!");

pub fn consume_n_if<P>(&mut self, n: usize, predicate: P) -> Option<&'a str> where
    P: FnOnce(&str) -> bool, 

Consumes n characters starting from the current position if the consumed string satisfies a predicate.

let mut cursor = InputCursor::new("hello world!");
assert_eq!(cursor.consume_n_if(5, |s| s.chars().all(|c| c.is_ascii_alphanumeric())), Some("hello"));
assert_eq!(cursor.remaining(), " world!");
assert_eq!(cursor.consume_n_if(5, |s| s.chars().all(|c| c.is_ascii_alphanumeric())), None);
assert_eq!(cursor.remaining(), " world!");
assert_eq!(cursor.consume_n_if(100, |_| true), None);

pub fn consume_if<P>(&mut self, predicate: P) -> Option<char> where
    P: FnOnce(char) -> bool, 

Consumes the following character if it satisfies the predicate.

let mut cursor = InputCursor::new("hello world!");
assert_eq!(cursor.consume_if(|c| c.is_ascii_alphanumeric()), Some('h'));
assert_eq!(cursor.consume_if(|c| c == ' '), None);

pub fn consume_while<P>(&mut self, predicate: P) -> Option<&'a str> where
    P: FnMut(char) -> bool, 

Consumes characters while the predicate is satisfied. Returns None if the string is empty.

let mut cursor = InputCursor::new("hello\nworld!");
assert_eq!(cursor.consume_while(|c| c != '\n'), Some("hello"));
assert_eq!(cursor.consume_while(|c| c != '\n'), None);
assert_eq!(cursor.next(), Some('\n'));

pub fn consume_first_n_while<P>(
    &mut self,
    n: usize,
    predicate: P
) -> Option<&'a str> where
    P: FnMut(char) -> bool, 

Consumes no more than n characters while they satisfy the predicate. Returns None if the string is empty.

let mut cursor = InputCursor::new("hello\nworld!");
assert_eq!(cursor.consume_first_n_while(4, |c| c != '\n'), Some("hell"));
assert_eq!(cursor.consume_first_n_while(4, |c| c != '\n'), Some("o"));
assert_eq!(cursor.consume_first_n_while(4, |c| c != '\n'), None);

pub fn starts_with(&self, s: &str) -> bool

Checks whether the remaining string starts with the given substring.

let mut cursor = InputCursor::new("hello\nworld!");
assert!(cursor.starts_with("hell"));
cursor.skip_n(2);
assert!(cursor.starts_with("llo\nw"));
assert!(!cursor.starts_with("jelly"));

pub fn skip_line(&mut self) -> Position

Skips the characters until the next line. Returns the position of the character preceding the line terminator (\r, \n, \r\n, \n\r).

let mut cursor = InputCursor::new("hello\r\nworld!");
let start = cursor.pos();
let end = cursor.skip_line();
assert_eq!(cursor.substr(start..=end), "hello");
assert_eq!(cursor.remaining(), "world!");

Trait Implementations

impl<'a> Clone for InputCursor<'a>

fn clone(&self) -> InputCursor<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for InputCursor<'a>

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

Formats the value using the given formatter.

impl<'a> Iterator for InputCursor<'a>

type Item = char

The type of the elements being iterated over.

fn next(&mut self) -> Option<char>

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn count(self) -> usize

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>

Consumes the iterator, returning the last element.

fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the nth element of the iterator.

fn step_by(self, step: usize) -> StepBy<Self>

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator, 

'Zips up' two iterators into a single iterator of pairs.

fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 

Takes a closure and creates an iterator which calls that closure on each element.

fn for_each<F>(self, f: F) where
    F: FnMut(Self::Item), 

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that [skip]s elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that yields elements based on a predicate.

fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> where
    P: FnMut(Self::Item) -> Option<B>, 

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

recently added

Creates an iterator that both yields elements based on a predicate and maps.

fn skip(self, n: usize) -> Skip<Self>

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: FnMut(&mut St, Self::Item) -> Option<B>, 

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    F: FnMut(Self::Item) -> U,
    U: IntoIterator, 

Creates an iterator that works like map, but flattens nested structure.

fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoIterator, 

Creates an iterator that flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first [None].

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item), 

Does something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

#[must_use = "if you really need to exhaust the iterator, consider `.for_each(drop)` instead"]fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where
    B: Default + Extend<Self::Item>,
    F: FnMut(&Self::Item) -> bool, 

Consumes an iterator, creating two collections from it.

fn partition_in_place<'a, T, P>(self, predicate: P) -> usize where
    P: FnMut(&T) -> bool,
    Self: DoubleEndedIterator<Item = &'a mut T>,
    T: 'a, 

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

new API

Reorders the elements of this iterator in-place according to the given predicate, such that all those that return true precede all those that return false. Returns the number of true elements found.

fn is_partitioned<P>(self, predicate: P) -> bool where
    P: FnMut(Self::Item) -> bool, 

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

new API

Checks if the elements of this iterator are partitioned according to the given predicate, such that all those that return true precede all those that return false.

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Ok = B>, 

An iterator method that applies a function as long as it returns successfully, producing a single, final value.

fn try_for_each<F, R>(&mut self, f: F) -> R where
    F: FnMut(Self::Item) -> R,
    R: Try<Ok = ()>, 

An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error.

fn fold<B, F>(self, init: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 

An iterator method that applies a function, producing a single, final value.

fn fold_first<F>(self, f: F) -> Option<Self::Item> where
    F: FnMut(Self::Item, Self::Item) -> Self::Item, 

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

The same as fold(), but uses the first element in the iterator as the initial value, folding every subsequent element into it. If the iterator is empty, return None; otherwise, return the result of the fold.

fn all<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: FnMut(&Self::Item) -> bool, 

Searches for an element of an iterator that satisfies a predicate.

fn find_map<B, F>(&mut self, f: F) -> Option<B> where
    F: FnMut(Self::Item) -> Option<B>, 

Applies function to the elements of iterator and returns the first non-none result.

fn try_find<F, E, R>(&mut self, f: F) -> Result<Option<Self::Item>, E> where
    F: FnMut(&Self::Item) -> R,
    R: Try<Ok = bool, Error = E>, 

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

new API

Applies function to the elements of iterator and returns the first non-none result or the first error.

fn position<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool, 

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool,
    Self: ExactSizeIterator + DoubleEndedIterator, 

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator, 

Reverses an iterator's direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
    FromA: Default + Extend<A>,
    FromB: Default + Extend<B>,
    Self: Iterator<Item = (A, B)>, 

Converts an iterator of pairs into a pair of containers.

fn copied<'a, T>(self) -> Copied<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Copy, 

Creates an iterator which copies all of its elements.

fn cloned<'a, T>(self) -> Cloned<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Clone, 

Creates an iterator which [clone]s all of its elements.

fn cycle(self) -> Cycle<Self> where
    Self: Clone, 

Repeats an iterator endlessly.

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 

Sums the elements of an iterator.

fn product<P>(self) -> P where
    P: Product<Self::Item>, 

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where
    I: IntoIterator<Item = Self::Item>,
    Self::Item: Ord, 

Lexicographically compares the elements of this Iterator with those of another.

fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
    I: IntoIterator, 

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
    I: IntoIterator, 

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn eq<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are equal to those of another.

fn eq_by<I, F>(self, other: I, eq: F) -> bool where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
    I: IntoIterator, 

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

Determines if the elements of this Iterator are equal to those of another with respect to the specified equality function.

fn ne<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

fn is_sorted(self) -> bool where
    Self::Item: PartialOrd<Self::Item>, 

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

new API

Checks if the elements of this iterator are sorted.

fn is_sorted_by<F>(self, compare: F) -> bool where
    F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>, 

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

new API

Checks if the elements of this iterator are sorted using the given comparator function.

fn is_sorted_by_key<F, K>(self, f: F) -> bool where
    F: FnMut(Self::Item) -> K,
    K: PartialOrd<K>, 

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

new API

Checks if the elements of this iterator are sorted using the given key extraction function.