ttyCharWidth

function ttyCharWidth(ch): number;

Compute the display width of a single character in a terminal cell.

Fast-paths ASCII (always 1) and uses codepointWidth for non-ASCII. Used by the diff engine for cursor tracking.

Parameters

Parameter	Type	Description
ch	string	A single character (may be a grapheme cluster).

Returns

number

0, 1, or 2.

Example

ttyCharWidth("a")  // 1
ttyCharWidth("文") // 2
ttyCharWidth("↗")  // 1