query.ml 16.7 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
open Parser.Hook
open Location
open Ast
open Ident
(********************************)
(* For options in driver/run.ml *)

let nooptim = ref false 

(********************************)


let exp pos e = LocatedExpr (loc_of_pos pos,e)


16 17 18
let ou (loc,e1,e2)= exp loc (Parser.logical_or e1 e2)
let et (loc,e1,e2)= exp loc (Parser.logical_and e1 e2)
let non (loc,e) = exp loc (Parser.logical_not e)
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33


type 'a  boolFormula =
    True
  | False
  | Varb of 'a
  | Not of 'a boolFormula
  | Ou  of 'a boolFormula * 'a boolFormula
  | Et  of 'a boolFormula * 'a boolFormula
  | Im  of 'a boolFormula * 'a boolFormula
  | OuN of 'a boolFormula list
  | EtN of 'a boolFormula list

let rec ast_of_bool(c,loc)=
	match (c,loc) with
34 35
	|(True,loc) -> cst_true
	|(False,loc) -> cst_false
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
	|(Varb(e),loc) -> e
	|(Not(Varb(e)),loc) -> non(loc,e)
	|(OuN([varb]),loc) -> ast_of_bool(varb,loc)
	|(OuN(l1::l2),loc) -> ou(loc,ast_of_bool(l1,loc),ast_of_bool(OuN(l2),loc))
	|(EtN([l]),loc) -> ast_of_bool(l,loc)  
	|(EtN(l1::l2),loc) -> et(loc,ast_of_bool(l1,loc),ast_of_bool(EtN(l2),loc)) 
	 (*pour le cas non optimise, ... *)
	|(Et(e1,e2),loc) -> et(loc,ast_of_bool(e1,loc),ast_of_bool(e2,loc))
	|(Ou(e1,e2),loc) -> ou(loc,ast_of_bool(e1,loc),ast_of_bool(e2,loc))
	| (_,_) -> assert false


let rec string_of_ppat p =
	let rec string_of_regexp rg =
	match rg with
51 52
	|Elem(e) -> string_of_ppat e
	|Guard(e) -> "/" ^ (string_of_ppat e)
53
	|SeqCapture(_,id,rg) -> U.get_str id ^"::"^ string_of_regexp rg
54 55 56 57 58 59 60 61
	|Seq(r1,r2) -> string_of_regexp r1 ^ " "^string_of_regexp r2
	|Alt(r1,r2) -> " ("^string_of_regexp r1 ^"|"^ string_of_regexp r2^")"
	|Star r1 -> string_of_regexp r1^"* "
	|WeakStar r1 -> string_of_regexp r1^"+ "
	|Epsilon -> ""
       in match p with 
       {loc = loc ; descr = descr } 
           -> ( match  descr with
62
             |PatVar(_,id) -> U.get_str ( id) 
63 64
	     |Cst(Atom a) -> U.get_str a
	     |Internal(descr) -> 
65 66
	         if descr=Builtin_defs.true_type then "`true" 
	         else if descr=Builtin_defs.false_type then "`false"
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
		 else if Types.is_empty descr then "Empty"
                 else if Types.atom ( Atoms.any)=descr then "_" 
		 else if Types.Record.any=descr then "_" 
		 else if Types.any=descr then "_" 
                 else  "" 
		 		 
	     |Or(p1,p2) -> " ("^string_of_ppat p1 ^"|"^ string_of_ppat p2^")"
	     |And(p1,p2) -> string_of_ppat p1 ^"&"^ string_of_ppat p2
	     |Diff(p1,p2) -> string_of_ppat p1 ^"-"^ string_of_ppat p2
	     |Prod(p1,p2) -> string_of_ppat p1 ^"> "^ string_of_ppat p2
	     |XmlT(p1,p2) -> "<"^string_of_ppat p1 ^ string_of_ppat p2
	     |Arrow(p1,p2) -> string_of_ppat p1 ^"->"^ string_of_ppat p2
	     |Optional(p1) -> string_of_ppat p1^"?"
(* a changer |Record(b,lm) -> let rec listing l=(match l with 
mais pas prioritaire          [] -> ""
			     |(s,ppat)::r -> " "^(U.get_str
                               ((LabelPool.value s)))^"="^string_of_ppat(ppat)^listing r
			     )in listing (lm)  *)	      
85
	     |Constant(i,t) -> U.get_str i
86
	     |Regexp(rg) -> "["^string_of_regexp rg ^ "]"
87 88 89 90 91 92
	     | _ ->"?"
	     )

let rec var_of_ppat x = 
    let rec var_of_rg rg =
	match rg with
93 94
	|Elem(e) -> []
	|Guard(e) -> []
95
	|SeqCapture(_,id,rg) -> [ident (Ns.empty,id)] @ var_of_rg rg
96 97 98 99 100 101 102 103 104
	|Seq(r1,r2) -> var_of_rg r1 @ var_of_rg r2
	|Alt(r1,r2) -> var_of_rg r1 @ var_of_rg r2
	|Star r1 -> var_of_rg r1
	|WeakStar r1 -> var_of_rg r1
	|Epsilon -> []

       in match x with 
       {loc = loc ; descr = descr } 
           -> ( match  descr with
105 106
             |PatVar(None,id) -> [ident (Ns.empty,id)]
	     |PatVar(Some _,_) -> []
107 108 109 110 111 112 113 114
	     |Internal(descr) ->  []
	     |Or(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |And(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |Diff(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |Prod(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |XmlT(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |Arrow(p1,p2) -> var_of_ppat p1 @ var_of_ppat p2
	     |Optional(p1) -> var_of_ppat p1
115 116 117 118 119 120 121 122
             |Record(b,lm) -> 
		let rec aux accu (_,(ppat,e)) = 
		  let accu = var_of_ppat ppat @ accu in
		  match e with
		    | None -> accu
		    | Some ppat -> var_of_ppat ppat @ accu
		in 
		List.fold_left aux [] lm
123
	     |Constant(i,t) -> [ident (Ns.empty,i)]
124
	     |Regexp(rg) -> var_of_rg rg
125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153
	     |_ ->[]
	     )

let rec string_of_pexpr x =
   let rec string_of_branches l =
      match l with
        [] -> "\n"
       |(p,e)::r -> "\n| "^string_of_ppat p ^" -> " ^ string_of_pexpr(e) ^ string_of_branches (r)  

   in match x with   
       | Integer i -> string_of_int(Intervals.V.get_int(i)) 
       | Atom a  -> "`" ^ U.get_str ( a)
       | Var( s) ->  U.get_str (s) 
       | Xml(e1,e2) -> " <" ^ string_of_pexpr e1 ^ ">" ^ string_of_pexpr e2 
       | Pair(e1,e2) -> "(" ^ string_of_pexpr e1 ^ "," ^ string_of_pexpr e2 ^ ")"
       | RecordLitt e  -> "att"
       | Char c  -> "\"" ^ Char.escaped (Chars.V.to_char c) ^ "\""
       | LocatedExpr(_,x) -> string_of_pexpr x
       | Apply(e1,e2) -> string_of_pexpr e1 ^ string_of_pexpr e2
       | Transform(e,b) -> " (transform "^string_of_pexpr e ^ " with"
                          ^string_of_branches(b) ^ ")"
       | Match(e,b) -> " (match "^string_of_pexpr e ^ " with"
                       ^string_of_branches(b) ^ ")"
       | Abstraction(_) -> "abstr "
       | Forget(_)->"frgt"
       | Map(e,b) -> "(map" ^string_of_pexpr e ^ " with"
                      ^string_of_branches(b) ^ ")"
       | Xtrans(e,b) -> "(xtransform" ^string_of_pexpr e ^ " with"
                      ^string_of_branches(b) ^ ")"
154
       | Dot(e1,_,_) -> "Dot(" ^ string_of_pexpr e1 ^",lbl)"
155 156 157 158 159 160 161 162 163
       | RemoveField (e,l) -> "RF(" ^ string_of_pexpr e ^",lbl)"	      
       | Const (Types.Atom a) -> (match (Atoms.V.value a) with
				 (_,utf) -> "`"^U.get_str utf )
       | Const(t) -> " Cst "
       | _ -> "!"

let rec var_of_pexpr x =
match x with
        LocatedExpr(_,x) -> var_of_pexpr x
164
       |Var(s) -> [ident (Ns.empty,s)]
165
       |Pair(e1,e2) -> var_of_pexpr e1 @ var_of_pexpr e2
166
       |Apply(e1,e2) ->  var_of_pexpr e1 @ var_of_pexpr e2
167 168 169 170
       |Transform(e,_) -> var_of_pexpr e
       |Match(e,_) -> var_of_pexpr e 
       |Map(e,_) -> var_of_pexpr e 
       |Xtrans(e,_) -> var_of_pexpr e 
171 172 173 174 175
       | _ -> []

let rec aff_var l =
	match l with
	[] -> ""
176
	| s::r -> Ident.to_string s ^" "^ aff_var r
177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329

(*************************************************
**************************************************
**************************************************)

(*
  [affBoolFormula] : boolFormula -> ('a -> string) -> string
  affiche une formule booleene sur 'a
*)


let rec affBoolFormula bf =
  let rec listAff l s =
    match l with
        [] -> ""
      | [a] -> affBoolFormula a
      | t::q ->
          (affBoolFormula t)
          ^s
          ^(listAff q s)
  in
  match bf with
      True -> "True"
    | False -> "False"
    | Varb(x) -> string_of_pexpr x 
    | Not(x) -> "Non("^(affBoolFormula x )^")"
    | Ou(x,y) -> "("
	^(affBoolFormula x )^" Ou "^(affBoolFormula y )^")"
    | Et(x,y) -> "("
	^(affBoolFormula x )^" Et "^(affBoolFormula y )^")"
    | Im(x,y) -> "("
	^(affBoolFormula x )^" => "^(affBoolFormula y )^")"
    | OuN(l) -> "{"^(listAff l " Ou ")^"}"
    | EtN(l) -> "["^(listAff l " Et ")^"]"
      

(****************************************
 * passage en forme normale conjonctive *
 ****************************************)

(*
  [supprimeImp] : boolFormula -> boolFormula
  \\supprime les implications 
*)
let rec supprimeImp bf =
  match bf with
      Im(bf1,bf2) ->
        Ou(Not(supprimeImp bf1),supprimeImp bf2)
    | Ou(bf1,bf2) ->
        let sbf1 = supprimeImp bf1 in
        let sbf2 = supprimeImp bf2 in
          Ou(sbf1,sbf2)
    | Et(bf1,bf2) ->
        let sbf1 = supprimeImp bf1 in
        let sbf2 = supprimeImp bf2 in
          Et(sbf1,sbf2)
    | Not(bf1) ->
        let sbf1 = supprimeImp bf1 in
          Not(sbf1)
    | _ -> bf

(*
  [notDown] : 'a boolFormula -> 'a boolFormula
*)
let rec notDown bf =
    match bf with
        Not(bf1) -> (
          match bf1 with
              Not(nbf1) -> notDown nbf1
            | True -> False
            | False -> True
            | Varb(a) -> Not(Varb(a))
            | Ou(nbf1,nbf2) ->
                Et(notDown (Not(nbf1)), notDown (Not(nbf2)))
            | Et(nbf1,nbf2) ->
                Ou(notDown (Not(nbf1)), notDown (Not(nbf2)))
            | _ ->
                bf
        )
      | Ou(bf1,bf2) ->
          Ou(notDown(bf1), notDown(bf2))
      | Et(bf1,bf2) ->
          Et(notDown(bf1), notDown(bf2))
      | _ -> bf

(*
  [downEt] : 'a boolFormula -> 'a boolFormula
*)
let rec downOu bf =
  match bf with
      Et(bf1,bf2) ->
        Et(downOu bf1, downOu bf2)
    | Ou(Et(bf1,bf2),bf3) ->
        Et(downOu (Ou(bf1,bf3)), downOu (Ou(bf2,bf3)))
    | Ou(bf3,Et(bf1,bf2)) ->
        Et(downOu (Ou(bf1,bf3)), downOu (Ou(bf2,bf3)))
    | Ou(bf1,bf2) ->
        let dbf1 = downOu bf1 in
        let dbf2 = downOu bf2 in
          (match (dbf1,dbf2) with
              (Et(bf3,bf4),bf5) ->
                Et(downOu (Ou(bf3,bf5)), downOu (Ou(bf4,bf5)))
            | (bf5,Et(bf3,bf4)) ->
                Et(downOu (Ou(bf3,bf5)), downOu (Ou(bf4,bf5)))
            | _ ->
                Ou(dbf1,dbf2))
    | _ -> bf

(*
  [etNaire] : 'a boolFormula -> 'a boolFormula
*)
let rec ouN bf =
  let rec aplatOu ebf =
    match ebf with
        True      -> [True]
      | False     -> [False]
      | Varb(a)    -> [Varb(a)]
      | Not(e)    -> [Not(e)]
      | Ou(e1,e2) -> (aplatOu e1)@(aplatOu e2)
      | _         -> assert false
  in
    match bf with
        Et(bf1,bf2) ->
          Et(ouN bf1, ouN bf2)
      | Ou(bf1,bf2) ->
          OuN ((aplatOu bf1)@(aplatOu bf2))
      | _ -> bf


(*
  [ouNaire] : 'a boolFormula -> 'a boolFormula
*)
let rec etN bf =
  let rec aplatEt ebf =
    match ebf with
      | Et(e1,e2) -> (aplatEt e1)@(aplatEt e2)
      | OuN(e) -> [OuN(e)]	
      | _ -> [OuN[ebf]]
  in
    match bf with
        Et(bf1,bf2) ->
          EtN ((aplatEt bf1)@(aplatEt bf2))
      |OuN(bf) -> EtN[OuN(bf)] 	  
      | _ -> EtN[OuN[bf]]


let rec purge e =
      match e with
       LocatedExpr(_,e) -> purge e
       | e ->e

(* code pas beau du tout, a reprendre clairement, c est pour evaluer que a="2"
est equivalent a "2"=a il reste a faire plusieurs petites choses encore...*)
330 331 332
let rec egal_expr(e1,e2) = e1 == e2
  (* On desactive cette optimisation pour le moment... *)
(*
333 334 335 336 337 338 339 340
 let egal_expr2(e1,e2)= string_of_pexpr(e1)=string_of_pexpr(e2) || egal_expr(e1,e2)
 in match (purge(e1),purge(e2)) with
  (Var(e1),Var(e2)) -> e1=e2
  |(Op(op1,[e1;e2]),Op(op2,[e3;e4])) 
     -> op1=op2 && ((egal_expr2(e1,e3) && (egal_expr2(e2,e4)))
                    || (op1="=" && (egal_expr2(e1,e4) && egal_expr2(e2,e3))))
       
  |_ -> false
341
*)
342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520

let rec appartient(t,l) =
	match (t,l) with
	(_,[]) -> false
        | (Varb(t),Varb(p)::r) -> 
		 if egal_expr(t,p) then true else appartient(Varb(t),r)
        | (Not(Varb(t)),Not(Varb(p))::r) -> 
		 if egal_expr(t,p) then true else appartient(Not(Varb(t)),r)
	| (t,p::r) ->  appartient(t,r)	

let rec retire_occurs l =
	match l with 
	 [] -> []
	 | t::q ->
             if (appartient(t,q)) then retire_occurs q
                                  else t::retire_occurs q

let rec is_false l =
        match l with
	 [] -> false
	 |Not(Varb(t))::q -> if appartient(Varb(t),q) then true else is_false(q)
	 | t::q-> is_false q

let rec contient_true l =
	match l with
	[] -> false
	|True::r -> true
	|p::r -> contient_true r  

let rec retire_false l =
	match l with
	[] -> []
	| False::r -> retire_false r
	| p:: r -> p::retire_false r

let rec simplifieOuN f=	  
   let rec simplifieOuN2 f =
      match f with
      OuN(l) -> let l =(retire_occurs l) 
                in if is_false l || is_false (List.rev l) then [True] 
	                       else l
      | _ -> assert false 	
   in let f=simplifieOuN2 f
      in let f = retire_false(f)
	 in if contient_true f then OuN[True]
	                       else OuN(f)  
   
let rec contient(l1,l2)=
  match(l1,l2)with
  (p1::r1,l2) -> (appartient(p1,l2) & contient(r1,l2)) 
  |([],l) -> true	   

let rec simplifieEtN loun =
   let rec aux(oun,l) =
   match(oun,l) with
   (OuN(o1),OuN(o2)::r) -> if contient(o1,o2) then aux(oun,r) 
                                             else OuN(o2)::aux(OuN(o1),r)
   |(_,[]) -> []
   | (_,b) -> b
   in match loun with
      (oun::r) -> oun::simplifieEtN(aux(oun,r))
      | [] -> []

let rec simplifie f =
  match f with
    EtN (loun) -> let rec aux loun = match loun with
                 [] -> []
		|OuN([True])::r -> aux r   
	        |oun::r -> simplifieOuN(oun)::aux(r)
               in 
	          let rec isFalse loun = match loun with
		  [] -> false
		  | OuN([False])::r -> true
		  |p::r -> isFalse r
	       in if isFalse loun then EtN[OuN[False]]
	                          else let s=aux(simplifieEtN(loun))
                                       in if s=[] then EtN[OuN[True]]
				                     else EtN(s) 
  | x -> EtN[OuN[x]]

let fnc bf = simplifie(etN(ouN(downOu(notDown(supprimeImp bf)))))	
(*************************************************
**************************************************
**************************************************)

let rec retirer_redondances l =
	let rec app(e,l)=
	    match (e,l) with
	    (e,[]) -> false
	    |(e,p::r) -> if e=p then true else app(e,r)
	
	in match l with
	[] -> []
	|p::r -> if app(p,r) then retirer_redondances r
	                     else p::retirer_redondances r 

let rec dans(lv,env)=
	let rec dans2(p,env)=
	    match (p,env)with 
	    (_,[])->false
	    |(p,h::t) -> (p=h) || dans2(p,t)  
	in match (lv,env) with
	([],env) -> true
	|(p::r,env) -> dans2(p,env)&&dans(r,env)

(* renvoie les clauses associees aux variables et la conjontions moins ces clauses*)
let rec c2(env,l)=
	match (env,l) with
	(env,[]) -> ([],[([True],[])]) 
	|(env,(lf,lv)::r)-> if dans(lv,env)
	             then (lf::fst(c2(env,r)),snd(c2(env,r)))
                     else (fst(c2(env,r)),(lf,lv)::snd(c2(env,r)))	


(*l:(Ast.pexpr boolFormula list * Ident.id list) list  *)
let rec place(t,l) =
	match (t,l) with
	([],_) -> []
	|([(i,p,x,env,c)],l2) ->  let l2 = match l2 with 
					|l->let rec reformate l =
					       match l with 
					       [] -> []
					       | (lf,lv)::r -> OuN(lf)::reformate(r)
					       in simplifie(EtN(reformate l))
				in [(i,p,x,env,l2)]  
        |((i,p,x,env,c)::r,l) -> let (c2,l2) = c2(env,l)
				 in let c2 = match c2 with 
					|l->let rec reformate l =
					       match l with 
					       [] -> []
					       | p::r -> OuN(p)::reformate(r)
					       in simplifie(EtN(reformate l))
				in(i,p,x,env,c2)::place(r,l2)

let rec sortir_clauses f =
    let rec aux f =
         let rec sortir_variables l =
      	     match l with
	        [] -> []
	        |Varb(p)::r -> var_of_pexpr p @ sortir_variables r
	        |Not(Varb(p))::r ->  var_of_pexpr p @ sortir_variables r
		|p::r-> sortir_variables r
         in match f with
             OuN(l) -> (l,sortir_variables(l))
	     |_ ->assert false
    in match f with 
      EtN([]) -> []
    | EtN(p::r) -> aux(p)::sortir_clauses(EtN(r))
    | _-> assert false 

let rec print_clauses l =
	match l with
	[] -> "\n"
	|(b,v)::r -> affBoolFormula(OuN(b)) ^":"^ aff_var(v) ^"-"^ print_clauses r
	 
let rec pp l =
	match l with
	| [] -> ()
	| (i,p,x,env,c)::l -> print_string "T";
	                  print_int i; 
			  print_string ": e= ";
	                  print_string (aff_var(var_of_pexpr x)) ;
			  print_string " p= ";
			  print_string (aff_var(var_of_ppat p));
			  print_string " c= ";
			  print_string (affBoolFormula c);
			  print_string " E=";
			  print_string (aff_var env);
			  print_string"\n";
			  pp l



(* t  est le tableau correspondant i,p,x,env,c *)
let select2(loc,e,t) = 
	let rec ifthenelse(c,e,loc)=
	   match c with
	   EtN[OuN[True]] -> e
	   |True -> e
521
	   |c -> exp loc (Parser.if_then_else (ast_of_bool(c,loc)) e cst_nil)
522 523 524 525 526 527 528 529 530 531 532 533 534 535 536
	in let rec saux loc e t = 
	(match t with	
	     [] -> exp loc (Pair(cst_nil,cst_nil))
	    |[(n,pn,xn,envn,cn)] -> 
	       let condi= ifthenelse(cn,exp loc e ,loc)
	       in exp loc (Transform(xn,[(pn,condi)]))
	       
	    |(i,pi,xi,envi,ci)::r-> 
	       let condi=ifthenelse(ci,(saux loc e r),loc)
	       in exp loc (Transform(xi,[(pi,condi)]))
	       
	)
	in saux loc e t 

let selectOpt(loc,e,l,condi) =
537 538 539 540 541 542 543 544 545 546 547 548 549 550 551
  let rec tableau (l,env,i) = 
    match l with
      | [] -> []
      | (p,x)::r -> 
	  let env2 = 
	    retirer_redondances (env @ var_of_pexpr x @ var_of_ppat p) in
	  (i,p,x,env2,True) :: (tableau (r,env2,i+1))
  in
  let tableau = tableau (l,[],1) in
(*  pp tableau; *)
  let t = place (tableau, sortir_clauses (fnc condi)) in
(*  pp t; *)
  let s = select2 (loc,e,t) in
(*  print_string(string_of_pexpr(s)); *)
  s
552 553 554 555 556 557 558 559 560 561 562

let select(loc,e,l) = 
	let rec saux loc l = 
	(match l with	
	     [] -> exp loc (Pair(cst_nil,cst_nil))
            |[(xn,en)] -> exp loc (Transform(en,[(xn,e)]))
	    |(xi,ei)::r-> exp loc (Transform(ei,[(xi,
	    (saux loc r))]))
	)
	in let s=saux loc l
	 in (*print_string(string_of_pexpr(s));*)s