Struct xi_unicode::LineBreakLeafIter

pub struct LineBreakLeafIter {
    pub(crate) ix: usize,
    pub(crate) state: u8,
}

A struct useful for computing line breaks in a rope or other non-contiguous string representation. This is a trickier problem than iterating in a string for a few reasons, the trickiest of which is that in the general case, line breaks require an indeterminate amount of look-behind.

This is something of an “expert-level” interface, and should only be used if the caller is prepared to respect all the invariants. Otherwise, you might get inconsistent breaks depending on start position and leaf boundaries.

Fields

ix: usize

state: u8

Implementations

impl LineBreakLeafIter

pub fn new(s: &str, ix: usize) -> LineBreakLeafIter

Create a new line break iterator suitable for leaves in a rope. Precondition: ix is at a code point boundary within s.

pub fn next(&mut self, s: &str) -> (usize, bool)

Return break pos and whether it’s a hard break. Note: hard break indication may go away, this may not be useful in actual application. If end of leaf is found, return leaf’s len. This does not indicate a break, as that requires at least one more codepoint of context. If it is a break, then subsequent next call will return an offset of 0. EOT is always a break, so in the EOT case it’s up to the caller to figure that out.

For consistent results, always supply same s until end of leaf is reached (and initially this should be the same as in the new call).

Trait Implementations

impl Clone for LineBreakLeafIter

fn clone(&self) -> LineBreakLeafIter

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Default for LineBreakLeafIter

fn default() -> LineBreakLeafIter

Returns the “default value” for a type.

impl Copy for LineBreakLeafIter