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|
(************************************************************************)
(* v * The Coq Proof Assistant / The Coq Development Team *)
(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016 *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(************************************************************************)
(*s Production of Scheme syntax. *)
open Pp
open Errors
open Util
open Names
open Miniml
open Mlutil
open Table
open Common
(*s Scheme renaming issues. *)
let keywords =
List.fold_right (fun s -> Id.Set.add (Id.of_string s))
[ "define"; "let"; "lambda"; "lambdas"; "match";
"apply"; "car"; "cdr";
"error"; "delay"; "force"; "_"; "__"]
Id.Set.empty
let pp_comment s = str";; "++h 0 s++fnl ()
let pp_header_comment = function
| None -> mt ()
| Some com -> pp_comment com ++ fnl () ++ fnl ()
let preamble _ comment _ usf =
pp_header_comment comment ++
str ";; This extracted scheme code relies on some additional macros\n" ++
str ";; available at http://www.pps.univ-paris-diderot.fr/~letouzey/scheme\n" ++
str "(load \"macros_extr.scm\")\n\n" ++
(if usf.mldummy then str "(define __ (lambda (_) __))\n\n" else mt ())
let pr_id id =
let s = Id.to_string id in
for i = 0 to String.length s - 1 do
if s.[i] == '\'' then s.[i] <- '~'
done;
str s
let paren = pp_par true
let pp_abst st = function
| [] -> assert false
| [id] -> paren (str "lambda " ++ paren (pr_id id) ++ spc () ++ st)
| l -> paren
(str "lambdas " ++ paren (prlist_with_sep spc pr_id l) ++ spc () ++ st)
let pp_apply st _ = function
| [] -> st
| [a] -> hov 2 (paren (st ++ spc () ++ a))
| args -> hov 2 (paren (str "@ " ++ st ++
(prlist_strict (fun x -> spc () ++ x) args)))
(*s The pretty-printer for Scheme syntax *)
let pp_global k r = str (Common.pp_global k r)
(*s Pretty-printing of expressions. *)
let rec pp_expr env args =
let apply st = pp_apply st true args in
function
| MLrel n ->
let id = get_db_name n env in apply (pr_id id)
| MLapp (f,args') ->
let stl = List.map (pp_expr env []) args' in
pp_expr env (stl @ args) f
| MLlam _ as a ->
let fl,a' = collect_lams a in
let fl,env' = push_vars (List.map id_of_mlid fl) env in
apply (pp_abst (pp_expr env' [] a') (List.rev fl))
| MLletin (id,a1,a2) ->
let i,env' = push_vars [id_of_mlid id] env in
apply
(hv 0
(hov 2
(paren
(str "let " ++
paren
(paren
(pr_id (List.hd i) ++ spc () ++ pp_expr env [] a1))
++ spc () ++ hov 0 (pp_expr env' [] a2)))))
| MLglob r ->
apply (pp_global Term r)
| MLcons (_,r,args') ->
assert (List.is_empty args);
let st =
str "`" ++
paren (pp_global Cons r ++
(if List.is_empty args' then mt () else spc ()) ++
prlist_with_sep spc (pp_cons_args env) args')
in
if is_coinductive r then paren (str "delay " ++ st) else st
| MLtuple _ -> error "Cannot handle tuples in Scheme yet."
| MLcase (_,_,pv) when not (is_regular_match pv) ->
error "Cannot handle general patterns in Scheme yet."
| MLcase (_,t,pv) when is_custom_match pv ->
let mkfun (ids,_,e) =
if not (List.is_empty ids) then named_lams (List.rev ids) e
else dummy_lams (ast_lift 1 e) 1
in
apply
(paren
(hov 2
(str (find_custom_match pv) ++ fnl () ++
prvect (fun tr -> pp_expr env [] (mkfun tr) ++ fnl ()) pv
++ pp_expr env [] t)))
| MLcase (typ,t, pv) ->
let e =
if not (is_coinductive_type typ) then pp_expr env [] t
else paren (str "force" ++ spc () ++ pp_expr env [] t)
in
apply (v 3 (paren (str "match " ++ e ++ fnl () ++ pp_pat env pv)))
| MLfix (i,ids,defs) ->
let ids',env' = push_vars (List.rev (Array.to_list ids)) env in
pp_fix env' i (Array.of_list (List.rev ids'),defs) args
| MLexn s ->
(* An [MLexn] may be applied, but I don't really care. *)
paren (str "error" ++ spc () ++ qs s)
| MLdummy _ ->
str "__" (* An [MLdummy] may be applied, but I don't really care. *)
| MLmagic a ->
pp_expr env args a
| MLaxiom -> paren (str "error \"AXIOM TO BE REALIZED\"")
and pp_cons_args env = function
| MLcons (_,r,args) when is_coinductive r ->
paren (pp_global Cons r ++
(if List.is_empty args then mt () else spc ()) ++
prlist_with_sep spc (pp_cons_args env) args)
| e -> str "," ++ pp_expr env [] e
and pp_one_pat env (ids,p,t) =
let r = match p with
| Pusual r -> r
| Pcons (r,l) -> r (* cf. the check [is_regular_match] above *)
| _ -> assert false
in
let ids,env' = push_vars (List.rev_map id_of_mlid ids) env in
let args =
if List.is_empty ids then mt ()
else (str " " ++ prlist_with_sep spc pr_id (List.rev ids))
in
(pp_global Cons r ++ args), (pp_expr env' [] t)
and pp_pat env pv =
prvect_with_sep fnl
(fun x -> let s1,s2 = pp_one_pat env x in
hov 2 (str "((" ++ s1 ++ str ")" ++ spc () ++ s2 ++ str ")")) pv
(*s names of the functions ([ids]) are already pushed in [env],
and passed here just for convenience. *)
and pp_fix env j (ids,bl) args =
paren
(str "letrec " ++
(v 0 (paren
(prvect_with_sep fnl
(fun (fi,ti) ->
paren ((pr_id fi) ++ spc () ++ (pp_expr env [] ti)))
(Array.map2 (fun id b -> (id,b)) ids bl)) ++
fnl () ++
hov 2 (pp_apply (pr_id (ids.(j))) true args))))
(*s Pretty-printing of a declaration. *)
let pp_decl = function
| Dind _ -> mt ()
| Dtype _ -> mt ()
| Dfix (rv, defs,_) ->
let names = Array.map
(fun r -> if is_inline_custom r then mt () else pp_global Term r) rv
in
prvecti
(fun i r ->
let void = is_inline_custom r ||
(not (is_custom r) &&
match defs.(i) with MLexn "UNUSED" -> true | _ -> false)
in
if void then mt ()
else
hov 2
(paren (str "define " ++ names.(i) ++ spc () ++
(if is_custom r then str (find_custom r)
else pp_expr (empty_env ()) [] defs.(i)))
++ fnl ()) ++ fnl ())
rv
| Dterm (r, a, _) ->
if is_inline_custom r then mt ()
else
hov 2 (paren (str "define " ++ pp_global Term r ++ spc () ++
(if is_custom r then str (find_custom r)
else pp_expr (empty_env ()) [] a)))
++ fnl2 ()
let rec pp_structure_elem = function
| (l,SEdecl d) -> pp_decl d
| (l,SEmodule m) -> pp_module_expr m.ml_mod_expr
| (l,SEmodtype m) -> mt ()
(* for the moment we simply discard module type *)
and pp_module_expr = function
| MEstruct (mp,sel) -> prlist_strict pp_structure_elem sel
| MEfunctor _ -> mt ()
(* for the moment we simply discard unapplied functors *)
| MEident _ | MEapply _ -> assert false
(* should be expanded in extract_env *)
let pp_struct =
let pp_sel (mp,sel) =
push_visible mp [];
let p = prlist_strict pp_structure_elem sel in
pop_visible (); p
in
prlist_strict pp_sel
let scheme_descr = {
keywords = keywords;
file_suffix = ".scm";
file_naming = file_of_modfile;
preamble = preamble;
pp_struct = pp_struct;
sig_suffix = None;
sig_preamble = (fun _ _ _ _ -> mt ());
pp_sig = (fun _ -> mt ());
pp_decl = pp_decl;
}
|
