Struct utf8_ranges::Utf8Sequences [] [src]

pub struct Utf8Sequences {
    // some fields omitted
}

An iterator over ranges of matching UTF-8 byte sequences.

The iteration represents an alternation of comprehensive byte sequences that match precisely the set of UTF-8 encoded scalar values.

A byte sequence corresponds to one of the scalar values in the range given if and only if it completely matches exactly one of the sequences of byte ranges produced by this iterator.

Each sequence of byte ranges matches a unique set of bytes. That is, no two sequences will match the same bytes.

Example

This shows how to match an arbitrary byte sequence against a range of scalar values.

use utf8_ranges::{Utf8Sequences, Utf8Sequence};

fn matches(seqs: &[Utf8Sequence], bytes: &[u8]) -> bool {
    for range in seqs {
        if range.matches(bytes) {
            return true;
        }
    }
    false
}

// Test the basic multilingual plane.
let seqs: Vec<_> = Utf8Sequences::new('\u{0}', '\u{FFFF}').collect();

// UTF-8 encoding of 'a'.
assert!(matches(&seqs, &[0x61]));
// UTF-8 encoding of '☃' (`\u{2603}`).
assert!(matches(&seqs, &[0xE2, 0x98, 0x83]));
// UTF-8 encoding of `\u{10348}` (outside the BMP).
assert!(!matches(&seqs, &[0xF0, 0x90, 0x8D, 0x88]));
// Tries to match against a UTF-8 encoding of a surrogate codepoint,
// which is invalid UTF-8, and therefore fails, despite the fact that
// the corresponding codepoint (0xD800) falls in the range given.
assert!(!matches(&seqs, &[0xED, 0xA0, 0x80]));
// And fails against plain old invalid UTF-8.
assert!(!matches(&seqs, &[0xFF, 0xFF]));

If this example seems circuitous, that's because it is! It's meant to be illustrative. In practice, you could just try to decode your byte sequence and compare it with the scalar value range directly. However, this is not always possible (for example, in a byte based automaton).

Methods

impl Utf8Sequences
[src]

fn new(start: char, end: char) -> Self

Create a new iterator over UTF-8 byte ranges for the scalar value range given.

Trait Implementations

impl Iterator for Utf8Sequences
[src]

type Item = Utf8Sequence

The type of the elements being iterated over.

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value. Read more

fn size_hint(&self) -> (usize, Option<usize>)
1.0.0

Returns the bounds on the remaining length of the iterator. Read more

fn count(self) -> usize
1.0.0

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

fn last(self) -> Option<Self::Item>
1.0.0

Consumes the iterator, returning the last element. Read more

fn nth(&mut self, n: usize) -> Option<Self::Item>
1.0.0

Consumes the n first elements of the iterator, then returns the next() one. Read more

fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> where U: IntoIterator<Item=Self::Item>
1.0.0

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

fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> where U: IntoIterator
1.0.0

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

fn map<B, F>(self, f: F) -> Map<Self, F> where F: FnMut(Self::Item) -> B
1.0.0

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

fn filter<P>(self, predicate: P) -> Filter<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0

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

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where F: FnMut(Self::Item) -> Option<B>
1.0.0

Creates an iterator that both filters and maps. Read more

fn enumerate(self) -> Enumerate<Self>
1.0.0

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

fn peekable(self) -> Peekable<Self>
1.0.0

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

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0

Creates an iterator that [skip()]s elements based on a predicate. Read more

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0

Creates an iterator that yields elements based on a predicate. Read more

fn skip(self, n: usize) -> Skip<Self>
1.0.0

Creates an iterator that skips the first n elements. Read more

fn take(self, n: usize) -> Take<Self>
1.0.0

Creates an iterator that yields its first n elements. Read more

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where F: FnMut(&mut St, Self::Item) -> Option<B>
1.0.0

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

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where F: FnMut(Self::Item) -> U, U: IntoIterator
1.0.0

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

fn fuse(self) -> Fuse<Self>
1.0.0

Creates an iterator which ends after the first None. Read more

fn inspect<F>(self, f: F) -> Inspect<Self, F> where F: FnMut(&Self::Item) -> ()
1.0.0

Do something with each element of an iterator, passing the value on. Read more

fn by_ref(&mut self) -> &mut Self
1.0.0

Borrows an iterator, rather than consuming it. Read more

fn collect<B>(self) -> B where B: FromIterator<Self::Item>
1.0.0

Transforms an iterator into a collection. Read more

fn partition<B, F>(self, f: F) -> (B, B) where B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool
1.0.0

Consumes an iterator, creating two collections from it. Read more

fn fold<B, F>(self, init: B, f: F) -> B where F: FnMut(B, Self::Item) -> B
1.0.0

An iterator adaptor that applies a function, producing a single, final value. Read more

fn all<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool
1.0.0

Tests if every element of the iterator matches a predicate. Read more

fn any<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool
1.0.0

Tests if any element of the iterator matches a predicate. Read more

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where P: FnMut(&Self::Item) -> bool
1.0.0

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

fn position<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool
1.0.0

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

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool, Self: ExactSizeIterator + DoubleEndedIterator
1.0.0

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

fn max(self) -> Option<Self::Item> where Self::Item: Ord
1.0.0

Returns the maximum element of an iterator. Read more

fn min(self) -> Option<Self::Item> where Self::Item: Ord
1.0.0

Returns the minimum element of an iterator. Read more

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B
1.6.0

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

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B
1.6.0

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

fn rev(self) -> Rev<Self> where Self: DoubleEndedIterator
1.0.0

Reverses an iterator's direction. Read more

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Iterator<Item=(A, B)>
1.0.0

Converts an iterator of pairs into a pair of containers. Read more

fn cloned<'a, T>(self) -> Cloned<Self> where Self: Iterator<Item=&'a T>, T: 'a + Clone
1.0.0

Creates an iterator which clone()s all of its elements. Read more

fn cycle(self) -> Cycle<Self> where Self: Clone
1.0.0

Repeats an iterator endlessly. Read more

fn sum<S>(self) -> S where S: Sum<Self::Item>
1.11.0

Sums the elements of an iterator. Read more

fn product<P>(self) -> P where P: Product<Self::Item>
1.11.0

Iterates over the entire iterator, multiplying all the elements Read more

fn cmp<I>(self, other: I) -> Ordering where I: IntoIterator<Item=Self::Item>, Self::Item: Ord
1.5.0

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

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0

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

fn eq<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>
1.5.0

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

fn ne<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>
1.5.0

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

fn lt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0

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

fn le<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0

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

fn gt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0

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

fn ge<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0

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