# units_join.ludic - a var() value's pieces joined, for a memo miss (units.ludic)
# the pieces as one text, made at its length at once (joined by + it left a text per piece behind)
function cv_join(ui_st: UiState) -> string {
  var n = 0
  for p in 0 .. len(ui_st.cv_texts) { n += len(ui_st.cv_texts[p]) }
  var out: pointer = null
  unsafe { out = bytes(n + 1) }
  var at = 0
  for p in 0 .. len(ui_st.cv_texts) {
    let t = ui_st.cv_texts[p]
    unsafe { for i in 0 .. len(t) { out[at + i] = t[i] } }
    at += len(t)
  }
  unsafe { out[n] = 0 }
  let s: string = out
  return s
}