Deque.pop_front_ready: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/src/containers/deque.bend as Deque
Lines 68-73 of bend-collections-laws-math@1.0.0.0/src/containers/deque.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/src/containers/deque.bend&start_line=68&end_line=73

import Base
import bend-collections-laws-math@1.0.0.0/src/containers/types/deque.bend as E

def pop_front_ready(~T: Data, d: Deque<T>) -> Deque<T> & Result<&2, &2, E.Error, T>:
  match d:
    case DE{Nil{}, b, nf, nb}:
      (DE{Nil{}, b, nf, nb}, Fail{E.EmptyDeque{}})
    case DE{Con{x, f}, b, nf, nb}:
      (DE{f, b, Nat.sub(nf, 1n), nb}, Done{x})

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/containers/deque.bend&name=Deque
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/containers/types/deque.bend&name=Error