Enum WidthMode 

pub enum WidthMode {
    Wc,
    Grapheme,
}

How grapheme clusters are measured for terminal-cell layout.

This enum does not control segmentation: grapheme_cells always segments by extended grapheme cluster. It controls only width calculation for each cluster. The East-Asian Ambiguous policy is orthogonal and is passed as a separate eaw_wide boolean to char_width and grapheme_width.

Variants

Wc

Measure each cluster by the width of its first code point.

This is wcwidth-style and intentionally cluster-blind: variation selectors, zero-width joiners, and emoji presentation overrides in the rest of the cluster do not change the result. Use this when matching older or simpler terminal width behavior is more important than cluster-aware emoji presentation.

Grapheme

Measure the whole grapheme cluster.

This mode accounts for variation selectors, regional indicators, zero-width-joiner sequences, and pictographic presentation when deciding whether a cluster occupies zero, one, or two cells. Use it for modern terminal rendering that treats emoji and joined clusters as a single displayed unit.

Implementations

impl WidthMode

pub fn grapheme_width(self, g: &str, eaw_wide: bool) -> u8

Measure one extended grapheme cluster under this mode.

In WidthMode::Wc mode, the width is the char_width of g’s first code point, or 0 for an empty string. In WidthMode::Grapheme mode, the width is grapheme_width for the whole cluster.

Parameters

• g — an extended grapheme cluster. Passing a longer string is accepted but only the first code point is considered in Wc mode.
• eaw_wide — East-Asian Ambiguous policy; see char_width.

Returns

The cluster width in terminal cells, normally 0, 1, or 2.

Errors and panics

This method does not fail or intentionally panic.

Trait Implementations

impl Clone for WidthMode

fn clone(&self) -> WidthMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WidthMode

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

Formats the value using the given formatter.

impl Default for WidthMode

fn default() -> WidthMode

Returns the “default value” for a type.

impl Hash for WidthMode

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 PartialEq for WidthMode

fn eq(&self, other: &WidthMode) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for WidthMode

impl Eq for WidthMode

impl StructuralPartialEq for WidthMode