Check.subs.dups: def of shake@0.7.0.0
Import: import shake@0.7.0.0/src/check.bend as Check
Lines 98-111 of shake@0.7.0.0/src/check.bend: https://jend.leeeet.dev/read.txt?path=shake@0.7.0.0/src/check.bend&start_line=98&end_line=111

import Base
import shake@0.7.0.0/src/cli.bend as C

# each subcommand's name against the earlier ones', and against `help`
def subs.dups(
  subs: List<&2, C.Sub>,
  +path: List<&2, String>,
  +names: List<&2, String>
) -> List<&2, SpecErr>:
  match subs:
    case Nil{}:
      []
    case Con{hh, tt}:
      C.Sub{+name, _a, _g, _c} = hh
      both(one(List.contains(~String, ~String.eq, names, name), SameSub{path, name}),
        both(one(String.eq(name, "help"), HelpSub{path}),
          subs.dups(tt, path, name <> names)))

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.contains
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.eq
  https://jend.leeeet.dev/definition.txt?path=shake@0.7.0.0/src/check.bend&name=SpecErr
  https://jend.leeeet.dev/definition.txt?path=shake@0.7.0.0/src/check.bend&name=both
  https://jend.leeeet.dev/definition.txt?path=shake@0.7.0.0/src/check.bend&name=one
  https://jend.leeeet.dev/definition.txt?path=shake@0.7.0.0/src/cli.bend&name=Sub