def osa.first
import shake@0.7.0.0/src/cli.bend as Cliimport Base
2248# the first row: `ii`, then one more for each char
2249def osa.first(bs: List<&2, Char>, +ii: Nat) -> List<&2, Nat>:
2250 match bs:
2251 case Nil{}:
2252 [ii]
2253 case Con{_c, tt}:
2254 ii <> osa.first(tt, 1n+ii)