Struct Char16TrieCursor 

pub struct Char16TrieCursor<'a> { /* private fields */ }

A cursor into a Char16Trie, useful for stepwise lookup.

Implementations

impl<'a> Char16TrieCursor<'a>

pub fn new(trie: &'a ZeroSlice<u16>) -> Self

Returns a new Char16TrieCursor backed by borrowed data for the trie array.

pub fn step(&mut self, c: char)

Steps the cursor one char into the trie.

Examples

use icu::collections::char16trie::Char16Trie;
use zerovec::ZeroVec;

// A Char16Trie containing the ASCII characters 'a' and 'ab'.
let trie_data = [48, 97, 176, 98, 32868];
let trie = Char16Trie::new(ZeroVec::from_slice_or_alloc(&trie_data));

let mut cursor = trie.cursor();
cursor.step('a');
assert_eq!(cursor.value(), Some(1));
assert!(!cursor.is_empty());
cursor.step('b');
assert_eq!(cursor.value(), Some(100));
assert!(cursor.is_empty());
cursor.step('c');
assert_eq!(cursor.value(), None);
assert!(cursor.is_empty());

pub fn step32(&mut self, c: u32)

Steps the cursor one code point (up to 0x10ffff) into the trie.

Examples

use icu::collections::char16trie::Char16Trie;
use zerovec::ZeroVec;

// A Char16Trie containing the ASCII characters 'a' and 'ab'.
let trie_data = [48, 97, 176, 98, 32868];
let trie = Char16Trie::new(ZeroVec::from_slice_or_alloc(&trie_data));

let mut cursor = trie.cursor();
cursor.step32('a' as u32);
assert_eq!(cursor.value(), Some(1));
assert!(!cursor.is_empty());
cursor.step32('b' as u32);
assert_eq!(cursor.value(), Some(100));
assert!(cursor.is_empty());
cursor.step32('c' as u32);
assert_eq!(cursor.value(), None);
assert!(cursor.is_empty());

pub fn step16(&mut self, c: u16)

Steps the cursor one 16-bit code unit into the trie.

Examples

use icu::collections::char16trie::Char16Trie;
use zerovec::ZeroVec;

// A Char16Trie containing the ASCII characters 'a' and 'ab'.
let trie_data = [48, 97, 176, 98, 32868];
let trie = Char16Trie::new(ZeroVec::from_slice_or_alloc(&trie_data));

let mut cursor = trie.cursor();
cursor.step16('a' as u16);
assert_eq!(cursor.value(), Some(1));
assert!(!cursor.is_empty());
cursor.step16('b' as u16);
assert_eq!(cursor.value(), Some(100));
assert!(cursor.is_empty());
cursor.step16('c' as u16);
assert_eq!(cursor.value(), None);
assert!(cursor.is_empty());

pub fn value(&self) -> Option<i32>

Returns the value at the current position.

pub fn is_empty(&self) -> bool

Checks whether the cursor points to an empty trie (i.e., no further units can be matched from the current position).

Use this to determine when to stop iterating.

Trait Implementations

impl<'a> Clone for Char16TrieCursor<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for Char16TrieCursor<'a>

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

Formats the value using the given formatter.

impl Write for Char16TrieCursor<'_>

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.