anchor.diff:  type FezCompileOpts =
       { OutputPath : string option
         NoBeam : bool
  +      DumpAst : bool
         Files : string list
       }
   
  
positive.code:         OPTIONS:
              -o | --output       set output directory
              --nobeam            do not compile core files to beam
  
      fez erl <args>
          Launches the erlang shell with the appropriate search paths set.
  
negative.code:                 inner {opts with OutputPath = Some outPath } tail
              | "--nobeam" :: tail ->
                  inner {opts with NoBeam = true } tail
              | ("-a" | "--dump-ast") :: tail ->
                  inner {opts with DumpAst = true } tail
              | files ->
                  {opts with Files = files }
  
          inner { OutputPath = None
                  NoBeam = false
                  DumpAst = false
                  Files = [] } argv
          |> Compile
  
  