anchor.diff:  let cmdRun () =
       let userDefs = ref []
       let userDefsStr = ref ""
  -    let inFile = ref None
  +    let inFile = ref ""
       let replLit = ref ""
       let rnglrArgs = ref ""
       let commandLineSpecs =
  
positive.code:          "-D", ArgType.String (fun s -> userDefs := !userDefs @ [s]), "User defined constants for YardFrontend lexer."
           "-U", ArgType.String (fun s -> userDefs := List.filter ((<>) s) !userDefs), 
                  "Remove previously defined constants for YardFrontend lexer."
           "-i", ArgType.String (fun s -> inFile := s|> Some), "Input grammar"
           "-module", ArgType.String (fun s -> rnglrArgs := !rnglrArgs + " -module " + s), "Target module name."
           "-token", ArgType.String (fun s -> rnglrArgs := !rnglrArgs + " -token " + s), "Token type."
           "-pos", ArgType.String (fun s -> rnglrArgs := !rnglrArgs + " -pos " + s), "Token position type."
  
negative.code:          "-replaceLiterals", ArgType.String (fun s -> replLit := s), "Replace literals regexp."
           ] |> List.map (fun (shortcut, argtype, description) -> ArgInfo(shortcut, argtype, description))
      ArgParser.Parse commandLineSpecs
      generate !inFile !replLit !rnglrArgs
  
  