# 1 "scope.cppo"
(* This example shows that the definition of FOO that is nested inside
   the (multi-line) definition of BAR affects only the body of the
   definition of BAR. It does not affect the text that follows a call
   to BAR. So, a multi-line macro definition acts as a scope delimiter. *)

# 11 "scope.cppo"
 "definition of FOO at the top level"  
# 11 "scope.cppo"
    (* expands to "definition of FOO at the top level" *)
# 12 "scope.cppo"

   "definition of FOO inside BAR"  (* expands to "definition of FOO inside BAR" *)
 
# 13 "scope.cppo"
 "definition of FOO at the top level"  
# 13 "scope.cppo"
    (* expands to "definition of FOO at the top level" *)

(* If one wishes to delimit a scope, without actually defining a macro,
   one can use #scope ... #endscope. *)


  
# 20 "scope.cppo"
   "first definition of HELLO"  
# 20 "scope.cppo"
        (* expands to "first definition of HELLO" *)

  
# 24 "scope.cppo"
   "second definition of HELLO"  
# 24 "scope.cppo"
        (* expands to "second definition of HELLO" *)
HELLO (* this does not expand *)

(* The effect of #scope ... #endscope can be simulated by writing
   #def DUMMY ... #enddef DUMMY #undef DUMMY
   but this is a bit unnatural. *)

# 36 "scope.cppo"

   "definition of HELLO inside the scope"  (* expands to "definition of HELLO inside the scope" *)
 
# 38 "scope.cppo"
HELLO (* this does not expand *)

(* Another simple example. *)


# 44 "scope.cppo"
let x = 
# 44 "scope.cppo"
         "I am defined"  
# 44 "scope.cppo"
           (* expands to "I am defined" *)
# 47 "scope.cppo"
let y = 
# 47 "scope.cppo"
         42  
# 47 "scope.cppo"
           (* expands to 42 *)

(* Check that the effect of #undef is also local.
   This example relies on the above definition of HI. *)


# 54 "scope.cppo"
let qwd = HI (* HI is not recognized as a macro and expands to itself *)
let z = 
# 56 "scope.cppo"
         42  
# 56 "scope.cppo"
           (* expands to 42 *)

(* Scopes can be nested. *)

# 61 "scope.cppo"
let x = 
# 61 "scope.cppo"
         0  
# 61 "scope.cppo"
              (* expands to 0 *)

  
# 65 "scope.cppo"
  let y = 
# 65 "scope.cppo"
           1  
# 65 "scope.cppo"
                (* expands to 1 *)

    
# 69 "scope.cppo"
    let z = 
# 69 "scope.cppo"
             2  
# 69 "scope.cppo"
                  (* expands to 2 *)
  let _ = 
# 71 "scope.cppo"
           1  
# 71 "scope.cppo"
                (* expands to 1 *)
let _ = 
# 73 "scope.cppo"
         0  
# 73 "scope.cppo"
              (* expands to 0 *)

(* Another example of nesting. *)



    
# 81 "scope.cppo"
    let message1 = 
# 81 "scope.cppo"
                    "Hello, "  
# 81 "scope.cppo"
                         ^ 
# 81 "scope.cppo"
                            "man" 
  
# 83 "scope.cppo"
  (* Here, MAN is no longer defined, but HELLO still is. *)
  let message2 = 
# 84 "scope.cppo"
                  "Hello, "  
# 84 "scope.cppo"
                       ^ "world"