src/Pure/Syntax/printer.ML

+(*  Title:      Pure/Syntax/printer
+    ID:         $Id$
+    Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen
+*)
+
+signature PRINTER0 =
+sig
+  val show_types: bool ref
+  val show_sorts: bool ref
+end;
+
+signature PRINTER =
+sig
+  include PRINTER0
+  structure Symtab: SYMTAB
+  structure XGram: XGRAM
+  structure Pretty: PRETTY
+  local open XGram XGram.Ast in
+    val pretty_ast: ast -> Pretty.T
+    val pretty_rule: (ast * ast) -> Pretty.T
+    val term_to_ast: (string -> (term list -> term) option) -> term -> ast
+    val typ_to_ast: (string -> (term list -> term) option) -> typ -> ast
+    type tab
+    val mk_print_tab: (string prod list) -> (ast list -> ast) Symtab.table -> tab
+    val pretty_term_ast: tab -> ast -> Pretty.T
+    val pretty_typ_ast: tab -> ast -> Pretty.T
+  end
+end;
+
+functor PrinterFun(structure Symtab: SYMTAB and Lexicon: LEXICON
+  and TypeExt: TYPE_EXT and SExtension: SEXTENSION and Pretty: PRETTY
+  sharing TypeExt.Extension = SExtension.Extension) (*: PRINTER *) =  (* FIXME *)
+struct
+
+structure Symtab = Symtab;
+structure Extension = TypeExt.Extension;
+structure XGram = Extension.XGram;
+structure Pretty = Pretty;
+open XGram XGram.Ast Lexicon TypeExt Extension SExtension;
+
+
+(** options for printing **)
+
+val show_types = ref false;
+val show_sorts = ref false;
+
+
+
+(** simple prettying **)
+
+(* pretty_ast *)
+
+fun pretty_ast (Constant a) = Pretty.str (quote a)
+  | pretty_ast (Variable x) = Pretty.str x
+  | pretty_ast (Appl asts) =
+      Pretty.blk
+        (2, (Pretty.str "(") ::
+          (separate (Pretty.brk 1) (map pretty_ast asts)) @ [Pretty.str ")"]);
+
+
+(* pretty_rule *)
+
+fun pretty_rule (lhs, rhs) =
+  Pretty.blk
+    (2, [pretty_ast lhs, Pretty.str "  ->", Pretty.brk 2, pretty_ast rhs]);
+
+
+
+(** convert term/typ to ast **)   (* FIXME check *)
+
+fun apply_trans a f args =
+  ((f args) handle
+    Match => raise Match
+  | exn => (writeln ("Error in translation for " ^ quote a); raise exn));
+
+
+fun ast_of_term trf show_types show_sorts tm =
+  let
+    val aprop_const = Const (apropC, dummyT);
+
+    fun fix_aprop (tm as Const _) = tm
+      | fix_aprop (tm as Free (x, ty)) =
+          if ty = propT then aprop_const $ Free (x, dummyT) else tm
+      | fix_aprop (tm as Var (xi, ty)) =
+          if ty = propT then aprop_const $ Var (xi, dummyT) else tm
+      | fix_aprop (tm as Bound _) = tm
+      | fix_aprop (Abs (x, ty, t)) = Abs (x, ty, fix_aprop t)
+      | fix_aprop (t1 $ t2) = fix_aprop t1 $ fix_aprop t2;
+
+
+    fun prune_typs (t_seen as (Const _, _)) = t_seen
+      | prune_typs (t as Free (x, ty), seen) =
+          if ty = dummyT then (t, seen)
+          else if t mem seen then (Free (x, dummyT), seen)
+          else (t, t :: seen)
+      | prune_typs (t as Var (xi, ty), seen) =
+          if ty = dummyT then (t, seen)
+          else if t mem seen then (Var (xi, dummyT), seen)
+          else (t, t :: seen)
+      | prune_typs (t_seen as (Bound _, _)) = t_seen
+      | prune_typs (Abs (x, ty, t), seen) =
+          let val (t', seen') = prune_typs (t, seen);
+          in (Abs (x, ty, t'), seen') end
+      | prune_typs (t1 $ t2, seen) =
+          let
+            val (t1', seen') = prune_typs (t1, seen);
+            val (t2', seen'') = prune_typs (t2, seen');
+          in
+            (t1' $ t2', seen'')
+          end;
+
+
+    fun ast_of (Const (a, _)) = trans a []
+      | ast_of (Free (x, ty)) = constrain x (Free (x, dummyT)) ty
+      | ast_of (Var (xi, ty)) = constrain (string_of_vname xi) (Var (xi, dummyT)) ty
+      | ast_of (Bound i) = Variable ("B." ^ string_of_int i)
+      | ast_of (t as Abs _) = ast_of (abs_tr' t)
+      | ast_of (t as _ $ _) =
+          (case strip_comb t of
+            (Const (a, _), args) => trans a args
+          | (f, args) => Appl (map ast_of (f :: args)))
+
+    and trans a args =
+      (case trf a of
+        Some f => ast_of (apply_trans a f args)
+      | None => raise Match)
+          handle Match => mk_appl (Constant a) (map ast_of args)
+
+    and constrain x t ty =
+      if show_types andalso ty <> dummyT then
+        ast_of (Const (constrainC, dummyT) $ t $ term_of_typ show_sorts ty)
+      else Variable x;
+  in
+    if show_types then ast_of (fst (prune_typs (fix_aprop tm, [])))
+    else ast_of (fix_aprop tm)
+  end;
+
+
+(* term_to_ast *)
+
+fun term_to_ast trf tm =
+  ast_of_term trf (! show_types) (! show_sorts) tm;
+
+
+(* typ_to_ast *)
+
+fun typ_to_ast trf ty =
+  ast_of_term trf false false (term_of_typ (! show_sorts) ty);
+
+
+
+(** type tab **)
+
+datatype symb =
+  Arg of int |
+  TypArg of int |
+  String of string |
+  Break of int |
+  Block of int * symb list;
+
+datatype format =
+  Prnt of symb list * int * int |
+  Trns of ast list -> ast |
+  TorP of (ast list -> ast) * (symb list * int * int);
+
+type tab = format Symtab.table;
+
+
+
+(** mk_print_tab **)
+
+fun mk_print_tab prods ast_trans =
+  let
+    fun nargs (Arg _ :: symbs) = nargs symbs + 1
+      | nargs (TypArg _ :: symbs) = nargs symbs + 1
+      | nargs (String _ :: symbs) = nargs symbs
+      | nargs (Break _ :: symbs) = nargs symbs
+      | nargs (Block (_, bsymbs) :: symbs) = nargs symbs + nargs bsymbs
+      | nargs [] = 0;
+
+    fun merge (s, String s' :: l) = String (s ^ s') :: l
+      | merge (s, l) = String s :: l;
+
+    fun mk_prnp sy opn p =
+      let
+        val constr = (opn = constrainC orelse opn = constrainIdtC);
+
+        fun syn2pr (Terminal s :: sy) =
+              let val (symbs, sy') = syn2pr sy
+              in (merge (s, symbs), sy') end
+          | syn2pr (Space s :: sy) =
+              let val (symbs, sy') = syn2pr sy
+              in (merge (s, symbs), sy') end
+          | syn2pr (Nonterminal (s, p) :: sy) =
+              let
+                val (symbs, sy') = syn2pr sy;
+                val symb =
+                  (if constr andalso s = "type" then TypArg else Arg)
+                    (if is_terminal s then 0 else p);
+              in (symb :: symbs, sy') end
+          | syn2pr (Bg i :: sy) =
+              let
+                val (bsymbs, sy') = syn2pr sy;
+                val (symbs, sy'') = syn2pr sy';
+              in (Block (i, bsymbs) :: symbs, sy'') end
+          | syn2pr (Brk i :: sy) =
+              let val (symbs, sy') = syn2pr sy
+              in (Break i :: symbs, sy') end
+          | syn2pr (En :: sy) = ([], sy)
+          | syn2pr [] = ([], []);
+
+        val (pr, _) = syn2pr sy;
+      in
+        (pr, nargs pr, p)
+      end;
+
+    fun add_prod (Prod (_, _, "", _), tab) = tab
+      | add_prod (Prod (_, sy, opn, p), tab) =
+          (case Symtab.lookup (tab, opn) of
+            None => Symtab.update ((opn, Prnt (mk_prnp sy opn p)), tab)
+          | Some (Prnt _) => tab
+          | Some (Trns f) => Symtab.update ((opn, TorP (f, mk_prnp sy opn p)), tab)
+          | Some (TorP _) => tab);
+
+    fun add_tr (tab, (opn, f)) = Symtab.update_new ((opn, Trns f), tab);
+  in
+    Symtab.balance
+      (foldr add_prod
+        (prods, foldl add_tr (Symtab.null, Symtab.alist_of ast_trans)))
+  end;
+
+
+
+(** pretty term/typ asts **)  (* FIXME check *)
+
+(*assumes a syntax derived from Pure*)
+
+fun pretty tab appT ast0 p0 =
+  let
+    fun synT ([], args) = ([], args)
+      | synT (Arg p :: symbs, t :: args) =
+          let val (Ts, args') = synT (symbs, args)
+          in (astT (t, p) @ Ts, args') end
+      | synT (TypArg p :: symbs, t :: args) =
+          let val (Ts, args') = synT (symbs, args)
+          in (pretty tab tappl_ast_tr' t p @ Ts, args') end
+      | synT (String s :: symbs, args) =
+          let val (Ts, args') = synT (symbs, args)
+          in (Pretty.str s :: Ts, args') end
+      | synT (Block (i, bsymbs) :: symbs, args) =
+          let
+            val (bTs, args') = synT (bsymbs, args);
+            val (Ts, args'') = synT (symbs, args');
+          in (Pretty.blk (i, bTs) :: Ts, args'') end
+      | synT (Break i :: symbs, args) =
+          let val (Ts, args') = synT (symbs, args)
+          in (Pretty.brk i :: Ts, args') end
+      | synT (_ :: _, []) = error "synT"
+
+    and parT (pr, args, p, p': int) =
+      if p > p' then fst (synT ([Block(1, String"(" :: pr @ [String")"])], args))
+      else fst (synT (pr, args))
+
+    and prefixT (_, a, [], _) = [Pretty.str a]
+      | prefixT (c, _, args, p) = astT (appT (c, args), p)
+
+    and combT (tup as (c, a, args, p)) =
+      let
+        val nargs = length args;
+        fun prnt (pr, n, p') =
+          if n = nargs then parT (pr, args, p, p')
+          else if n > nargs then prefixT tup
+          else astT (appT (c, args), p);     (* FIXME ??? *)
+      in
+        case Symtab.lookup (tab, a) of
+          None => prefixT tup
+        | Some (Prnt prnp) => prnt prnp
+        | Some (Trns f) =>
+            (astT (apply_trans a f args, p) handle Match => prefixT tup)
+        | Some (TorP (f, prnp)) =>
+            (astT (apply_trans a f args, p) handle Match => prnt prnp)
+      end
+
+    and astT (c as Constant a, p) = combT (c, a, [], p)
+      | astT (Variable x, _) = [Pretty.str x]
+      | astT (Appl ((c as Constant a) :: args), p) = combT (c, a, args, p)
+      | astT (Appl (f :: (args as _ :: _)), p) = astT (appT (f, args), p)
+      | astT (ast as (Appl _), _) = raise_ast "pretty: malformed ast" [ast];
+  in
+    astT (ast0, p0)
+  end;
+
+
+(* pretty_term_ast *)
+
+fun pretty_term_ast tab ast =
+  Pretty.blk (0, pretty tab appl_ast_tr' ast 0);
+
+
+(* pretty_typ_ast *)
+
+fun pretty_typ_ast tab ast =
+  Pretty.blk (0, pretty tab tappl_ast_tr' ast 0);
+
+
+end;
+