Generic.Sum.checked: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/math/generic.bend as Generic
Lines 204-206 of bend-collections-laws-crypto@1.0.0.0/spec/math/generic.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/math/generic.bend&start_line=204&end_line=206

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/num.bend as N
import bend-collections-laws-crypto@1.0.0.0/src/math/generic.bend as G
import bend-collections-laws-crypto@1.0.0.0/spec/math/natural.bend as NS

# the partial sums only grow, so the sum overflows exactly when the total does
def Sum.checked(~T: Data, ~op: N.Op<T> -> T, ~test: N.Test<T> -> Bool, ~val: T -> Nat, ~of: Nat -> T, +w: Nat, xs: List<&2, T>) -> Type:
  {G.sum(~T, ~op, ~test, xs) == checked(~T, ~of, w, NS.lsum(vals(~T, ~val, xs))) : Result<&2, &2, N.NumError, T>}

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/math/generic.bend&name=checked
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/math/generic.bend&name=vals
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/math/natural.bend&name=lsum
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/generic.bend&name=sum
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/num.bend&name=NumError
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/num.bend&name=Op
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/math/num.bend&name=Test