def cluster

bend-kit-tty@0.1.0.1 · text.bend:21

import Base
import bend-kit-tty@0.1.0.1/width.bend as W

21# A grapheme cluster takes its first code point's columns (W.w); VS16 makes a narrow base an emoji, 2 wide.
22def cluster(g: String) -> U32:
23  match g:
24    case SNil{}:
25      0
26    case SCon{Chr{+c}, t}:
27      +w = W.w(c)
28      Bool.pick(U32, U32.is_eq(w, 1) && vs16(t), 2, w)