Refactoring of process classes in faustexp.ml.

[Faustine.git] / interpretor / faustexp.ml

diff --git a/interpretor/faustexp.ml b/interpretor/faustexp.ml
index d0b5ec0..cc725ba 100644 (file)
--- a/interpretor/faustexp.ml
+++ b/interpretor/faustexp.ml
@@ -16,6 +16,12 @@ exception NotYetDone;;
 exception Dimension_error of string;;
 exception Process_error of string;;
 
 exception Dimension_error of string;;
 exception Process_error of string;;
 

+
+(* PARSER *)
+
+let exp_of_string s = (Parser.main Lexer.token (Lexing.from_string s));;
+
+

 class dimension : int * int -> dimension_type = 
   fun (init : int * int) -> 
     object (self)
 class dimension : int * int -> dimension_type = 
   fun (init : int * int) -> 
     object (self)


@@ -55,59 +61,30 @@ class dimension : int * int -> dimension_type =
          else raise (Dimension_error "rec dimension not matched.")
     end;;
 
          else raise (Dimension_error "rec dimension not matched.")
     end;;
 

-(*
-class process : faust_exp -> process_type = 
+class virtual process = 

   fun (exp_init : faust_exp) ->
   fun (exp_init : faust_exp) ->

-  object (self)
-    val exp = exp_init
-    val left = 
-      match exp_init with
-      |        Const b -> exp_init
-      |        Ident s -> exp_init
-      |        Par (e1, e2) -> e1
-      |        Seq (e1, e2) -> e1
-      |        Split (e1, e2) -> e1
-      |        Merge (e1, e2) -> e1
-      |        Rec (e1, e2) -> e1
-
-    val right = 
-      match exp_init with
-      |        Const b -> exp_init
-      |        Ident s -> exp_init
-      |        Par (e1, e2) -> e2
-      |        Seq (e1, e2) -> e2
-      |        Split (e1, e2) -> e2
-      |        Merge (e1, e2) -> e2
-      |        Rec (e1, e2) -> e2
-
-    val proc_left = 
-
-      val dim = new dimension
-      val delay = 0
-      method get_exp = exp
-      method get_dim = dim
-      method get_delay = delay
-      method to_string = "NotYetDone"
-      method virtual evaluate : beam_type -> beam_type
-  end;;
-*)
+    object
+      val _exp = exp_init
+      val virtual _dim : dimension_type
+      val virtual _delay : int
+      method exp = _exp
+      method dim = _dim
+      method delay = _delay
+      method virtual eval : beam_type -> beam_type
+    end

 
 class proc_const : faust_exp -> process_type = 
   fun (exp_init : faust_exp) ->
 
 class proc_const : faust_exp -> process_type = 
   fun (exp_init : faust_exp) ->

+    let _const = 
+      match exp_init with
+      | Const b -> b
+      | _ -> raise (Process_error "const process constructor.") in
+

     object (self)
     object (self)

-      val _exp = exp_init
+      inherit process exp_init

       val _dim = new dimension (0,1)
       val _delay = 0
       val _dim = new dimension (0,1)
       val _delay = 0

-      val _const = 
-       match exp_init with
-       | Const b -> b
-       | _ -> raise (Process_error "const process constructor.")
-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay

       method private const = _const
       method private const = _const

-

       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
          if input#get = [||] then
       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
          if input#get = [||] then


@@ -119,24 +96,20 @@ class proc_const : faust_exp -> process_type =
 
 class proc_ident : faust_exp -> process_type = 
   fun (exp_init : faust_exp) ->
 
 class proc_ident : faust_exp -> process_type = 
   fun (exp_init : faust_exp) ->

-    object (self)
-      val _exp = exp_init
-      val _symbol = 
-       match exp_init with
-       | Ident s -> s
-       | _ -> raise (Process_error "ident process constructor.")
+    let _symbol = 
+         match exp_init with
+         | Ident s -> s
+         | _ -> raise (Process_error "ident process constructor.") in

 
 

-      val _dim = new dimension (dimension_of_symbol self#symb)
+    object (self)
+      inherit process exp_init
+      val _dim = new dimension (dimension_of_symbol _symbol)

       val _delay = delay_of_symbol _symbol      
       val _delay = delay_of_symbol _symbol      

-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay
-      method symb = _symbol
+      method private symb = _symbol

 
       method private beam_of_ident : int -> signal_type -> beam_type = 
        fun (n : int) ->
 
       method private beam_of_ident : int -> signal_type -> beam_type = 
        fun (n : int) ->

-         fun (s, signal_type) ->
+         fun (s : signal_type) ->

            if n = (self#dim)#input then 
              new beam [|s|]
            else raise (Process_error ("Ident " ^ string_of_symbol self#symb))
            if n = (self#dim)#input then 
              new beam [|s|]
            else raise (Process_error ("Ident " ^ string_of_symbol self#symb))


@@ -148,25 +121,38 @@ class proc_ident : faust_exp -> process_type =
          | Pass -> self#beam_of_ident n input#get.(0)
          | Stop -> if n = 1 then new beam [||] 
                    else raise (Process_error "Ident !")
          | Pass -> self#beam_of_ident n input#get.(0)
          | Stop -> if n = 1 then new beam [||] 
                    else raise (Process_error "Ident !")

-         | Add -> self#beam_of_ident n ((input#get.(0))#add input#get.(1))
-         | Sub -> self#beam_of_ident n ((input#get.(0))#sub input#get.(1))
-         | Mul -> self#beam_of_ident n ((input#get.(0))#mul input#get.(1))
-         | Div -> self#beam_of_ident n ((input#get.(0))#div input#get.(1))
-         | Mem -> self#beam_of_ident n ((input#get.(0))#mem)
-         | Delay -> self#beam_of_ident n ((input#get.(0))#delay input#get.(1))
-         | Floor -> self#beam_of_ident n ((input#get.(0))#floor)
-         | Int -> self#beam_of_ident n ((input#get.(0))#int)
-         | Sin -> self#beam_of_ident n ((input#get.(0))#sin)
-         | Cos -> self#beam_of_ident n ((input#get.(0))#cos)
-         | Atan -> self#beam_of_ident n ((input#get.(0))#atan)
-         | Atan2 -> self#beam_of_ident n ((input#get.(0))#atan2 input#get.(1))
-         | Sqrt -> self#beam_of_ident n ((input#get.(0))#sqrt)
+         | Add -> self#beam_of_ident n 
+               ((input#get.(0))#add input#get.(1))
+         | Sub -> self#beam_of_ident n 
+               ((input#get.(0))#sub input#get.(1))
+         | Mul -> self#beam_of_ident n 
+               ((input#get.(0))#mul input#get.(1))
+         | Div -> self#beam_of_ident n 
+               ((input#get.(0))#div input#get.(1))
+         | Mem -> self#beam_of_ident n 
+               ((input#get.(0))#mem)
+         | Delay -> self#beam_of_ident n 
+               ((input#get.(0))#delay input#get.(1))
+         | Floor -> self#beam_of_ident n 
+               ((input#get.(0))#floor)
+         | Int -> self#beam_of_ident n 
+               ((input#get.(0))#int)
+         | Sin -> self#beam_of_ident n 
+               ((input#get.(0))#sin)
+         | Cos -> self#beam_of_ident n 
+               ((input#get.(0))#cos)
+         | Atan -> self#beam_of_ident n 
+               ((input#get.(0))#atan)
+         | Atan2 -> self#beam_of_ident n 
+               ((input#get.(0))#atan2 input#get.(1))
+         | Sqrt -> self#beam_of_ident n 
+               ((input#get.(0))#sqrt)

          | Rdtable -> self#beam_of_ident n 
                ((input#get.(1))#rdtable input#get.(0) input#get.(2))
          | Mod -> self#beam_of_ident n 
                ((input#get.(0))#_mod input#get.(1))
          | Vectorize -> self#beam_of_ident n 
          | Rdtable -> self#beam_of_ident n 
                ((input#get.(1))#rdtable input#get.(0) input#get.(2))
          | Mod -> self#beam_of_ident n 
                ((input#get.(0))#_mod input#get.(1))
          | Vectorize -> self#beam_of_ident n 

-               ((input#get.(0))#vectorzie input#get.(1))
+               ((input#get.(0))#vectorize input#get.(1))

          | Vconcat -> self#beam_of_ident n 
                ((input#get.(0))#vconcat input#get.(1))
          | Vpick -> self#beam_of_ident n 
          | Vconcat -> self#beam_of_ident n 
                ((input#get.(0))#vconcat input#get.(1))
          | Vpick -> self#beam_of_ident n 


@@ -179,165 +165,103 @@ class proc_ident : faust_exp -> process_type =
                ((input#get.(0))#smaller input#get.(1))
          | Prefix -> self#beam_of_ident n 
                ((input#get.(1))#prefix input#get.(0))
                ((input#get.(0))#smaller input#get.(1))
          | Prefix -> self#beam_of_ident n 
                ((input#get.(1))#prefix input#get.(0))

-         | Selec2 -> self#beam_of_ident n 
+         | Select2 -> self#beam_of_ident n 

                ((input#get.(0))#select2 input#get.(1) input#get.(2))
          | Select3 -> self#beam_of_ident n 
                ((input#get.(0))#select3 input#get.(1) 
                   input#get.(2) input#get.(3))
       end;;
 
                ((input#get.(0))#select2 input#get.(1) input#get.(2))
          | Select3 -> self#beam_of_ident n 
                ((input#get.(0))#select3 input#get.(1) 
                   input#get.(2) input#get.(3))
       end;;
 

-
-class proc_par : faust_exp -> process_type = 
+class virtual process_binary =

   fun (exp_init : faust_exp) ->
   fun (exp_init : faust_exp) ->

-    object (self)
-      val _exp = exp_init
-      val _exp_left = 
+    let (exp_left, exp_right) = 
+      match exp_init with
+      | Par (e1, e2) -> (e1, e2)
+      |        Seq (e1, e2) -> (e1, e2)
+      |        Split (e1, e2) -> (e1, e2)
+      |        Merge (e1, e2) -> (e1, e2)
+      |        Rec (e1, e2) -> (e1, e2)
+      | _ -> raise (Process_error "binary process constructor.") in
+    let proc_left = (new proc_factory)#make exp_left in
+    let proc_right = (new proc_factory)#make exp_right in
+    
+    object
+      inherit process exp_init
+      method private proc_left = proc_left
+      method private proc_right = proc_right
+
+      val _dim = 

        match exp_init with
        match exp_init with

-       | Par (e1, e2) -> e1
-       | _ -> raise (Process_error "par process constructor.")
-      val _exp_right = 
+       | Par (e1, e2) -> (proc_left#dim)#par proc_right#dim
+       | Seq (e1, e2) -> (proc_left#dim)#seq proc_right#dim
+       | Split (e1, e2) -> (proc_left#dim)#split proc_right#dim
+       | Merge (e1, e2) -> (proc_left#dim)#merge proc_right#dim
+       | Rec (e1, e2) -> (proc_left#dim)#_rec proc_right#dim
+       | _ -> raise (Process_error "binary process constructor.")
+
+      val _delay = 

        match exp_init with
        match exp_init with

-       | Par (e1, e2) -> e2
-       | _ -> raise (Process_error "par process constructor.")
-
-      val proc_left = (new proc_factory)#make _exp_left
-      val proc_right = (new proc_factory)#make _exp_right
-
-      val _dim = (proc_left#dim)#par proc_right#dim
-      val _delay = max proc_left#delay proc_right#delay
-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay
-
+       | Par (e1, e2) -> max proc_left#delay proc_right#delay
+       | Seq (e1, e2) -> proc_left#delay + proc_right#delay
+       | Split (e1, e2) -> proc_left#delay + proc_right#delay
+       | Merge (e1, e2) -> proc_left#delay + proc_right#delay
+       | Rec (e1, e2) -> proc_left#delay + proc_right#delay
+       | _ -> raise (Process_error "binary process constructor.")
+    end
+
+and proc_par : faust_exp -> process_type = 
+  fun (exp_init : faust_exp) ->
+    object (self)
+      inherit process_binary exp_init

       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->

-         let (sub_input1, sub_input2) = input#cut proc_left#dim#input in
-         let sub_output1 = proc_left#eval sub_input1 in
-         let sub_output2 = proc_right#eval sub_input2 in
+         let (sub_input1, sub_input2) = input#cut self#proc_left#dim#input in
+         let sub_output1 = self#proc_left#eval sub_input1 in
+         let sub_output2 = self#proc_right#eval sub_input2 in

          sub_output1#append sub_output2
       end
 
 and proc_split : faust_exp -> process_type =
   fun (exp_init : faust_exp) ->
     object (self)
          sub_output1#append sub_output2
       end
 
 and proc_split : faust_exp -> process_type =
   fun (exp_init : faust_exp) ->
     object (self)

-      val _exp = exp_init
-      val _exp_left = 
-       match exp_init with
-       | Split (e1, e2) -> e1
-       | _ -> raise (Process_error "par process constructor.")
-      val _exp_right = 
-       match exp_init with
-       | Split (e1, e2) -> e2
-       | _ -> raise (Process_error "par process constructor.")
-
-      val proc_left = (new proc_factory)#make _exp_left
-      val proc_right = (new proc_factory)#make _exp_right
-
-      val _dim = (proc_left#dim)#split proc_right#dim
-      val _delay = proc_left#delay + proc_right#delay
-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay
-
+      inherit process_binary exp_init

       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->

-         let mid_output = proc_left#eval input in
-         let mid_input = mid_output#matching proc_right#dim#input in
-         proc_right#eval mid_input
+         let mid_output = self#proc_left#eval input in
+         let mid_input = mid_output#matching self#proc_right#dim#input in
+         self#proc_right#eval mid_input

       end
 
 
 and proc_merge : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
     object (self)
       end
 
 
 and proc_merge : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
     object (self)

-      val _exp = exp_init
-      val _exp_left = 
-       match exp_init with
-       | Merge (e1, e2) -> e1
-       | _ -> raise (Process_error "merge process constructor.")
-      val _exp_right = 
-       match exp_init with
-       | Merge (e1, e2) -> e2
-       | _ -> raise (Process_error "merge process constructor.")
-
-      val proc_left = (new proc_factory)#make _exp_left
-      val proc_right = (new proc_factory)#make _exp_right
-
-      val _dim = (proc_left#dim)#merge proc_right#dim
-      val _delay = proc_left#delay + proc_right#delay
-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay
-
+      inherit process_binary exp_init

       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->

-         let mid_output = proc_left#eval input in
-         let mid_input = mid_output#matching proc_right#dim#input in
-         proc_right#eval mid_input
-
+         let mid_output = self#proc_left#eval input in
+         let mid_input = mid_output#matching self#proc_right#dim#input in
+         self#proc_right#eval mid_input

       end
 
 and proc_seq : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
     object (self)
       end
 
 and proc_seq : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
     object (self)

-      val _exp = exp_init
-      val _exp_left = 
-       match exp_init with
-       | Seq (e1, e2) -> e1
-       | _ -> raise (Process_error "seq process constructor.")
-      val _exp_right = 
-       match exp_init with
-       | Seq (e1, e2) -> e2
-       | _ -> raise (Process_error "seq process constructor.")
-
-      val proc_left = (new proc_factory)#make _exp_left
-      val proc_right = (new proc_factory)#make _exp_right
-
-      val _dim = (proc_left#dim)#seq proc_right#dim
-      val _delay = proc_left#delay + proc_right#delay
-
-      method exp = _exp
-      method dim = _dim
-      method delay = _delay
-
+      inherit process_binary exp_init

       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->
       method eval : beam_type -> beam_type = 
        fun (input : beam_type) ->

-         let mid_output = proc_left#eval input in
-         proc_right#eval mid_output
+         let mid_output = self#proc_left#eval input in
+         self#proc_right#eval mid_output

       end
 
 and proc_rec : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
   object (self)
       end
 
 and proc_rec : faust_exp -> process_type =
   fun (exp_init : faust_exp) -> 
   object (self)

-    val _exp = exp_init
-    val _exp_left = 
-      match exp_init with
-      | Rec (e1, e2) -> e1
-      | _ -> raise (Process_error "rec process constructor.")
-    val _exp_right = 
-      match exp_init with
-      | Rec (e1, e2) -> e2
-      | _ -> raise (Process_error "rec process constructor.")
-           
-    val proc_left = (new proc_factory)#make _exp_left
-    val proc_right = (new proc_factory)#make _exp_right
-
-    val _dim = (proc_left#dim)#_rec proc_right#dim
-    val _delay = proc_left#delay
-       
-    method exp = _exp
-    method dim = _dim
-    method delay = _delay
-       
+    inherit process_binary exp_init

     method eval : beam_type -> beam_type = 
       fun (input : beam_type) ->
     method eval : beam_type -> beam_type = 
       fun (input : beam_type) ->

-       let mid_output = proc_left#eval input in
-       proc_right#eval mid_output
-         
-
+       let mid_output = self#proc_left#eval input in
+       self#proc_right#eval mid_output

   end
 
 and proc_factory = 
   end
 
 and proc_factory = 


@@ -353,145 +277,3 @@ and proc_factory =
          | Merge (e1, e2) -> new proc_merge exp
          | Rec (e1, e2) -> new proc_rec exp
   end;;
          | Merge (e1, e2) -> new proc_merge exp
          | Rec (e1, e2) -> new proc_rec exp
   end;;

-
-
-
-
-
-(* PROCESS DELAY ESTIMATION *)
-
-(** val delay : faust_exp -> int, returns the number of delays estimated staticly.
-Attention: delays of "@" is estimated as 10 constant, 
-delays of "vectorize" and "serialize" haven't been implemented, 
-delays of "rdtable" hasn't been implemented.*)
-let rec delay exp_faust = match exp_faust with
-       |Const v        ->      0
-       |Ident s        ->
-               (
-                       match s with
-                       |Add                    ->      0
-                       |Sup                    ->      0               
-                       |Mul                    ->      0
-                       |Div                    ->      0
-                       |Pass                   ->      0
-                       |Stop                   ->      0
-                       |Mem                    ->      1
-                       |Delay                  ->      100000 
-                       |Floor                  ->      0
-                       |Int                    ->      0
-                       |Sin                    ->      0
-                       |Rdtable                ->      100000
-                       |Mod                    ->      0
-                       |Larger                 ->      0
-                       |Smaller                ->      0
-                       |Vectorize              ->      100
-                       |Concat                 ->      0
-                       |Nth                    ->      0
-                       |Serialize              ->      0
-                       |Prefix                 ->      1
-                       |Selecttwo              ->      0
-                       |Selectthree            ->      0
-               )
-       |Par (e1, e2)   ->      max (delay e1) (delay e2)
-       |Seq (e1, e2)   ->      (delay e1) + (delay e2)
-       |Split (e1, e2) ->      (delay e1) + (delay e2)
-       |Merge (e1, e2) ->      (delay e1) + (delay e2)
-       |Rec (e1, e2)   ->      delay e1;;      
-
-
-(* PARSER *)
-
-(** val exp_of_string : string -> faust_exp, faust expression parser. *)
-let exp_of_string s = (Parser.main Lexer.token (Lexing.from_string s));;
-
-
-
-(* PROCESS DIMENSION ESTIMATION *)
-(* process dimension := (size of input beam, size of output beam).*)
-
-
-(** val get_root : dimension -> int * int, returns the root of dimension tree. *)
-let get_root = fun d_tree -> match d_tree with
-                        | End d -> d
-                       | Tree (d, branches) -> d;;
-
-
-(** val subtree : dimention -> int -> dimension, returns a subtree of dimension tree.*)
-let subtree = fun d_tree -> fun i ->
-  match d_tree with
-  | End d -> raise (Beam_Matching_Error "Subtree left absent.")
-  | Tree (d, branches) -> (
-      match branches with 
-       (left, right) -> if i = 0 then left else right);;
-
-(** val subtree_left : dimension -> dimension, returns the left subtree of dimension tree.*)
-let subtree_left = fun d_tree -> subtree d_tree 0;;
-
-
-(** val subtree_right : dimension -> dimension, returns the right subtree of dimension tree.*)
-let subtree_right = fun d_tree -> subtree d_tree 1;;
-
-(** val dim : faust_exp -> int * int, returns dimension for faust expression, 
-along with beam matching.*)
-let rec dim exp_faust = 
-
-(** val dimension_constructor : ((int * int) -> (int * int) -> (int * int)) -> faust_exp 
--> faust_exp -> dimension,
-returns the dimension tree of constructor(e1, e2).*)
-        let dimension_constructor = fun constructor -> fun e1 -> fun e2 ->
-           let subtree1 = dim e1 in
-           let subtree2 = dim e2 in
-           let root = constructor (get_root subtree1) (get_root subtree2) in
-           Tree (root, (subtree1, subtree2)) in
-
-        match exp_faust with
-       |Const v -> End (0, 1)
-       |Ident s -> 
-               (
-                       match s with
-                       |Add                    ->      End (2, 1)
-                       |Sup                    ->      End (2, 1)              
-                       |Mul                    ->      End (2, 1)
-                       |Div                    ->      End (2, 1)
-                       |Pass                   ->      End (1, 1)
-                       |Stop                   ->      End (1, 0)
-                       |Mem                    ->      End (1, 1)
-                       |Delay                  ->      End (2, 1)
-                       |Floor                  ->      End (1, 1)
-                       |Int                    ->      End (1, 1)
-                       |Sin                    ->      End (1, 1)
-                       |Rdtable                ->      End (3, 1)
-                       |Mod                    ->      End (2, 1)
-                       |Vectorize              ->      End (2, 1)
-                       |Concat                 ->      End (2, 1)
-                       |Nth                    ->      End (2, 1)
-                       |Serialize              ->      End (1, 1)
-                       |Larger                 ->      End (2, 1)
-                       |Smaller                ->      End (2, 1)
-                       |Prefix                 ->      End (2, 1)
-                       |Selecttwo              ->      End (3, 1)
-                       |Selectthree            ->      End (4, 1)
-               )
-
-       |Par (e1, e2)           ->      dimension_constructor d_par e1 e2
-       |Seq (e1, e2)           ->      dimension_constructor d_seq e1 e2
-       |Split (e1, e2)         ->      dimension_constructor d_split e1 e2
-       |Merge (e1, e2)         ->      dimension_constructor d_merge e1 e2
-       |Rec (e1, e2)           ->      dimension_constructor d_rec e1 e2;;
-
-
-
-(* AUXILIARY 'CONVERT_TO_STRING' FUNCTIONS *)
-
-(** val print_exp : faust_exp -> unit, print to console the input faust expression.*)
-let print_exp exp = 
-  let rec string_of_exp exp = match exp with
-    |Const v           ->      "Const" ^ " (" ^ (string_of_value v) ^ ")"
-    |Ident s           ->      "Ident" ^ " \"" ^ "s" ^ "\""
-    |Par (e1, e2)      ->      "Par" ^ " (" ^ (string_of_exp e1) ^ ", " ^ (string_of_exp e2) ^ ")"
-    |Seq (e1, e2)      ->      "Seq" ^ " (" ^ (string_of_exp e1) ^ ", " ^ (string_of_exp e2) ^ ")"
-    |Split (e1, e2)    ->      "Split" ^ " (" ^ (string_of_exp e1) ^ ", " ^ (string_of_exp e2) ^ ")"
-    |Merge (e1, e2)    ->      "Merge" ^ " (" ^ (string_of_exp e1) ^ ", " ^ (string_of_exp e2) ^ ")"
-    |Rec (e1, e2)      ->      "Rec" ^ " (" ^ (string_of_exp e1) ^ ", " ^ (string_of_exp e2) ^ ")"
-  in
-    print_string("Parer : Types.faust_exp = "^ (string_of_exp exp));;