anchor.diff:              indexOf "Start symbol" nonterminals startSymbol
               |> writeSingleValued w startSymbolHeader
   
  +        let writeResizeArray w (xs: ResizeArray<_>) =
  +            let count = xs.Count
  +            let mem = ArrayPool.Shared.Rent count
  +            try
  +                xs.CopyTo(mem)
  +                writeRecord w (ReadOnlySpan(mem, 0, count))
  +            finally
  +                ArrayPool.Shared.Return mem
  +
           let writeGroups w noiseSymbols (groups: ImmutableArray<Group>) =
               let arr = ResizeArray()
   
  
positive.code: 
              for i = 0 to groups.Length - 1 do
                  let group = groups.[i]
                  arr.Add <| Entry.String group.Name
                  arr.Add <| Entry.Boolean group.IsTerminal
                  arr.Add <|
  
negative.code:                     match span.[i + 4] with
                      | Entry.Empty -> None
                      | Entry.String str -> Some <| GroupEnd str
                      | e -> invalidEGTf "Cannot retrieve group end for %s. Got %A." name e
                  let advanceMode =
                      match wantByte span (i + 5) with
                      | 'T'B -> AdvanceMode.Token
                      | 'C'B -> AdvanceMode.Character
                      | x -> invalidEGTf "Cannot retrieve group advance mode for %s. Got %x." name x
                  let endingMode =
                      match wantByte span (i + 6) with
                      | 'O'B -> EndingMode.Open
                      | 'C'B -> EndingMode.Closed
                      | x -> invalidEGTf "Cannot retrieve group ending mode for %s. Got %x." name x
                  let nestingCount = wantUInt32 span (i + 7) |> int
                  i <- i + 8
  
                  let nesting =
                      let nesting = ImmutableHashSet.CreateBuilder()
                      let span = span.Slice(i)
                      for i = 0 to span.Length - 1 do
                          nesting.Add(wantUInt32 span i) |> ignore
                      nesting.ToImmutable()
  
                  groups.Add {
  