Text.cluster: def of bend-kit-tty@0.1.0.1
Import: import bend-kit-tty@0.1.0.1/text.bend as Text
Lines 21-28 of bend-kit-tty@0.1.0.1/text.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-tty@0.1.0.1/text.bend&start_line=21&end_line=28

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

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

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.pick
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Char
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_eq
  https://jend.leeeet.dev/definition.txt?path=bend-kit-tty@0.1.0.1/text.bend&name=vs16
  https://jend.leeeet.dev/definition.txt?path=bend-kit-tty@0.1.0.1/width.bend&name=w