Toplevel support

• Playing with toplevel

  If you have Fan installed successfully, start your toplevel, and try the next phrase:

  #directory "+fan";;
  # #load "fanTop.cma";;
  # let a = %exp-{|3 };;
  val a : FAstN.exp = \`Int "3"
  

  Here exp- is a built-in DDSL for quasiquotation, it’s the same as exp DDSL except without locations, see Fan’s quosi-quotation

  There are two directives added:

  1. normal

     #normal;;
     

     This directive would restore the toplevel to the default behavior, it’s useful sometimes, for examlpe, you want to load a normal ocaml file instead of file pre-processed by Fan.

  2. fan

     #fan;;
     

     It will turn on the features of fan.

  Warning

  Don’t fire the toplevel in the sourceree, as you may notice, there’s a .ocamlinit file there which requires a customized toplevel, so fire the toplevel in any other place you like.

• Playing with Utop

  Utop is a toplevel with nice auto-completion support, it’s very helpful for explore some libraries which the user is not familiar with.

  Todo

  There is adapter for fan, namely ftop, available here: https://github.com/bobzhang/ftop

  To install ftop:

  $ make clean
  $ make
  $ make install
  

  Then you would have ftop in your path. Since ftop already linked fan in, so it works out of the box.

  ftop$ let a = %exp-{ 3 };;
  val a: FAstN.exp = `Int "3"
  

  However, you still have to type "#directory "+fan" to get access to Fan’s typing environment /i.e./ cmi files.