src/HOL/Boogie/Tools/boogie_loader.ML
author boehmes
Mon Mar 22 09:40:11 2010 +0100 (2010-03-22)
changeset 35862 c2039b00ff0d
parent 35856 f81557a124d5
child 35895 387de5db0a74
permissions -rw-r--r--
replaced old-style Drule.add_axiom by Specification.axiomatization
     1 (*  Title:      HOL/Boogie/Tools/boogie_loader.ML
     2     Author:     Sascha Boehme, TU Muenchen
     3 
     4 Loading and interpreting Boogie-generated files.
     5 *)
     6 
     7 signature BOOGIE_LOADER =
     8 sig
     9   val load_b2i: bool -> (string * int) list -> Path.T -> theory -> theory
    10 end
    11 
    12 structure Boogie_Loader: BOOGIE_LOADER =
    13 struct
    14 
    15 fun log verbose text args x =
    16   if verbose andalso not (null args)
    17   then (Pretty.writeln (Pretty.big_list text (map Pretty.str args)); x)
    18   else x
    19 
    20 val isabelle_name =
    21   let 
    22     fun purge s = if Symbol.is_letter s orelse Symbol.is_digit s then s else
    23       (case s of
    24         "." => "_o_"
    25       | "_" => "_n_"
    26       | "$" => "_S_"
    27       | "@" => "_G_"
    28       | "#" => "_H_"
    29       | "^" => "_T_"
    30       | _   => ("_" ^ string_of_int (ord s) ^ "_"))
    31   in prefix "b_" o translate_string purge end
    32 
    33 fun drop_underscore s =
    34   try (unsuffix "_") s
    35   |> Option.map drop_underscore
    36   |> the_default s
    37 
    38 val short_name =
    39   translate_string (fn s => if Symbol.is_letdig s then s else "") #>
    40   drop_underscore
    41 
    42 (* these prefixes must be distinct: *)
    43 val var_prefix = "V_"
    44 val label_prefix = "L_"
    45 val position_prefix = "P_"
    46 
    47 val no_label_name = label_prefix ^ "unknown"
    48 fun label_name line col =
    49   if line = 0 orelse col = 0 then no_label_name
    50   else label_prefix ^ string_of_int line ^ "_" ^ string_of_int col
    51 
    52 fun mk_syntax name i =
    53   let
    54     val syn = Syntax.escape name
    55     val args = space_implode ",/ " (replicate i "_")
    56   in
    57     if i = 0 then Mixfix (syn, [], 1000)
    58     else Mixfix (syn ^ "()'(/" ^ args ^ "')", replicate i 0, 1000)
    59   end
    60 
    61 
    62 datatype attribute_value = StringValue of string | TermValue of term
    63 
    64 
    65 
    66 local
    67   fun lookup_type_name thy name arity =
    68     let val intern = Sign.intern_type thy name
    69     in
    70       if Sign.declared_tyname thy intern
    71       then
    72         if Sign.arity_number thy intern = arity then SOME intern
    73         else error ("Boogie: type already declared with different arity: " ^
    74           quote name)
    75       else NONE
    76     end
    77 
    78   fun log_new bname name = bname ^ " (as " ^ name ^ ")"
    79   fun log_ex bname name = "[" ^ bname ^ " has already been declared as " ^
    80     name ^ "]"
    81 
    82   fun declare (name, arity) thy =
    83     let val isa_name = isabelle_name name
    84     in
    85       (case lookup_type_name thy isa_name arity of
    86         SOME type_name => (((name, type_name), log_ex name type_name), thy)
    87       | NONE =>
    88           let
    89             val args = map (rpair dummyS) (Name.invents Name.context "'a" arity)
    90             val (T, thy') =
    91               Typedecl.typedecl_global (Binding.name isa_name, args, mk_syntax name arity) thy
    92             val type_name = fst (Term.dest_Type T)
    93           in (((name, type_name), log_new name type_name), thy') end)
    94     end
    95 in
    96 fun declare_types verbose tys =
    97   fold_map declare tys #>> split_list #-> (fn (tds, logs) =>
    98   log verbose "Declared types:" logs #>
    99   rpair (Symtab.make tds))
   100 end
   101 
   102 
   103 
   104 local
   105   fun maybe_builtin T =
   106     let
   107       fun const name = SOME (Const (name, T))
   108       fun const2_abs name =
   109         let val U = Term.domain_type T
   110         in
   111           SOME (Abs (Name.uu, U, Abs (Name.uu, U,
   112             Const (name, T) $ Bound 0 $ Bound 1)))
   113         end
   114 
   115       fun choose builtin =
   116         (case builtin of
   117           "bvnot" => const @{const_name bitNOT}
   118         | "bvand" => const @{const_name bitAND}
   119         | "bvor" => const @{const_name bitOR}
   120         | "bvxor" => const @{const_name bitXOR}
   121         | "bvadd" => const @{const_name plus}
   122         | "bvneg" => const @{const_name uminus}
   123         | "bvsub" => const @{const_name minus}
   124         | "bvmul" => const @{const_name times}
   125         | "bvudiv" => const @{const_name div}
   126         | "bvurem" => const @{const_name mod}
   127         | "bvsdiv" => const @{const_name sdiv}
   128         | "bvsrem" => const @{const_name srem}
   129         | "bvshl" => const @{const_name bv_shl}
   130         | "bvlshr" => const @{const_name bv_lshr}
   131         | "bvashr" => const @{const_name bv_ashr}
   132         | "bvult" => const @{const_name less}
   133         | "bvule" => const @{const_name less_eq}
   134         | "bvugt" => const2_abs @{const_name less}
   135         | "bvuge" => const2_abs @{const_name less_eq}
   136         | "bvslt" => const @{const_name word_sless}
   137         | "bvsle" => const @{const_name word_sle}
   138         | "bvsgt" => const2_abs @{const_name word_sless}
   139         | "bvsge" => const2_abs @{const_name word_sle}
   140         | "zero_extend" => const @{const_name ucast}
   141         | "sign_extend" => const @{const_name scast}
   142         | _ => NONE)
   143 
   144       fun is_builtin att =
   145         (case att of
   146           ("bvbuiltin", [StringValue builtin]) => choose builtin
   147         | ("bvint", [StringValue "ITE"]) => const @{const_name If}
   148         | _ => NONE)
   149     in get_first is_builtin end
   150 
   151   fun lookup_const thy name T =
   152     let val intern = Sign.intern_const thy name
   153     in
   154       if Sign.declared_const thy intern
   155       then
   156         if Sign.typ_instance thy (T, Sign.the_const_type thy intern)
   157         then SOME (Const (intern, T))
   158         else error ("Boogie: function already declared with different type: " ^
   159           quote name)
   160       else NONE
   161     end
   162 
   163   fun log_term thy t = Syntax.string_of_term_global thy t
   164   fun log_new thy name t = name ^ " (as " ^ log_term thy t ^ ")"
   165   fun log_ex thy name t = "[" ^ name ^ " has already been declared as " ^
   166     log_term thy t ^ "]"
   167   fun log_builtin thy name t = "[" ^ name ^ " has been identified as " ^
   168     log_term thy t ^ "]"
   169 
   170   fun declare' name isa_name T arity atts thy =
   171     (case lookup_const thy isa_name T of
   172       SOME t => (((name, t), log_ex thy name t), thy)
   173     | NONE =>
   174         (case maybe_builtin T atts of
   175           SOME t => (((name, t), log_builtin thy name t), thy)
   176         | NONE =>
   177             thy
   178             |> Sign.declare_const ((Binding.name isa_name, T),
   179                  mk_syntax name arity)
   180             |> (fn (t, thy') => (((name, t), log_new thy' name t), thy'))))
   181   fun declare (name, ((Ts, T), atts)) =
   182     declare' name (isabelle_name name) (Ts ---> T) (length Ts) atts
   183 
   184   fun uniques fns fds =
   185     let
   186       fun is_unique (name, (([], _), atts)) =
   187             (case AList.lookup (op =) atts "unique" of
   188               SOME _ => Symtab.lookup fds name
   189             | NONE => NONE)
   190         | is_unique _ = NONE
   191       fun mk_unique_axiom T ts =
   192         Const (@{const_name distinct}, HOLogic.listT T --> @{typ bool}) $
   193           HOLogic.mk_list T ts
   194     in
   195       map_filter is_unique fns
   196       |> map (swap o Term.dest_Const)
   197       |> AList.group (op =)
   198       |> map (fn (T, ns) => mk_unique_axiom T (map (Const o rpair T) ns))
   199     end
   200 in
   201 fun declare_functions verbose fns =
   202   fold_map declare fns #>> split_list #-> (fn (fds, logs) =>
   203   log verbose "Loaded constants:" logs #>
   204   rpair (` (uniques fns) (Symtab.make fds)))
   205 end
   206 
   207 
   208 
   209 local
   210   fun name_axioms axs =
   211     let fun mk_name idx = "axiom_" ^ string_of_int (idx + 1)
   212     in map_index (fn (idx, t) => (mk_name idx, HOLogic.mk_Trueprop t)) axs end
   213 
   214   datatype kind = Unused of thm | Used of thm | New of string
   215 
   216   fun mark (name, t) axs =
   217     (case Termtab.lookup axs t of
   218       SOME (Unused thm) => Termtab.update (t, Used thm) axs
   219     | NONE => Termtab.update (t, New name) axs
   220     | SOME _ => axs)
   221 
   222   val sort_fst_str = sort (prod_ord fast_string_ord (K EQUAL)) 
   223   fun split_list_kind thy axs =
   224     let
   225       fun split (_, Used thm) (used, new) = (thm :: used, new)
   226         | split (t, New name) (used, new) = (used, (name, t) :: new)
   227         | split (_, Unused thm) (used, new) =
   228            (warning (Pretty.str_of
   229              (Pretty.big_list "This background axiom has not been loaded:"
   230                [Display.pretty_thm_global thy thm]));
   231             (used, new))
   232     in apsnd sort_fst_str (fold split axs ([], [])) end
   233 
   234   fun mark_axioms thy axs =
   235     Boogie_Axioms.get (ProofContext.init thy)
   236     |> Termtab.make o map (fn thm => (Thm.prop_of thm, Unused thm))
   237     |> fold mark axs
   238     |> split_list_kind thy o Termtab.dest
   239 in
   240 fun add_axioms verbose axs thy =
   241   let
   242     val (used, new) = mark_axioms thy (name_axioms axs)
   243     fun add (n, t) =
   244       Specification.axiomatization [] [((Binding.name n, []), [t])] #>>
   245       hd o hd o snd
   246   in
   247     thy
   248     |> fold_map add new
   249     |-> Context.theory_map o fold Boogie_Axioms.add_thm
   250     |> log verbose "The following axioms were added:" (map fst new)
   251     |> (fn thy' => log verbose "The following axioms already existed:"
   252          (map (Display.string_of_thm_global thy') used) thy')
   253   end
   254 end
   255 
   256 
   257 
   258 local
   259   fun burrow_distinct eq f xs =
   260     let
   261       val ys = distinct eq xs
   262       val tab = ys ~~ f ys
   263     in map (the o AList.lookup eq tab) xs end
   264 
   265   fun indexed names =
   266     let
   267       val dup = member (op =) (duplicates (op =) (map fst names))
   268       fun make_name (n, i) = n ^ (if dup n then "_" ^ string_of_int i else "")
   269     in map make_name names end
   270 
   271   fun rename idx_names =
   272     idx_names
   273     |> burrow_fst (burrow_distinct (op =)
   274          (map short_name #> ` (duplicates (op =)) #-> Name.variant_list))
   275     |> indexed
   276 in
   277 fun add_vcs verbose vcs thy =
   278   let val vcs' = burrow_fst rename vcs
   279   in
   280     thy
   281     |> Boogie_VCs.set vcs'
   282     |> log verbose "The following verification conditions were loaded:"
   283          (map fst vcs')
   284   end
   285 end
   286 
   287 
   288 
   289 local
   290   fun mk_bitT i T =
   291     if i = 0
   292     then Type (@{type_name "Numeral_Type.bit0"}, [T])
   293     else Type (@{type_name "Numeral_Type.bit1"}, [T])
   294 
   295   fun mk_binT size = 
   296     if size = 0 then @{typ "Numeral_Type.num0"}
   297     else if size = 1 then @{typ "Numeral_Type.num1"}
   298     else let val (q, r) = Integer.div_mod size 2 in mk_bitT r (mk_binT q) end
   299 in
   300 fun mk_wordT size =
   301   if size >= 0 then Type (@{type_name "word"}, [mk_binT size])
   302   else raise TYPE ("mk_wordT: " ^ quote (string_of_int size), [], [])
   303 end
   304 
   305 local
   306   fun dest_binT T =
   307     (case T of
   308       Type (@{type_name "Numeral_Type.num0"}, _) => 0
   309     | Type (@{type_name "Numeral_Type.num1"}, _) => 1
   310     | Type (@{type_name "Numeral_Type.bit0"}, [T]) => 2 * dest_binT T
   311     | Type (@{type_name "Numeral_Type.bit1"}, [T]) => 1 + 2 * dest_binT T
   312     | _ => raise TYPE ("dest_binT", [T], []))
   313 in
   314 val dest_wordT = (fn
   315     Type (@{type_name "word"}, [T]) => dest_binT T
   316   | T => raise TYPE ("dest_wordT", [T], []))
   317 end
   318 
   319 fun mk_arrayT (Ts, T) = Type (@{type_name "fun"}, [HOLogic.mk_tupleT Ts, T])
   320 
   321 
   322 
   323 datatype token = Token of string | Newline | EOF
   324 
   325 fun tokenize path =
   326   let
   327     fun blank c = (c = #" " orelse c = #"\t" orelse c = #"\n" orelse c = #"\r")
   328     fun split line (i, tss) = (i + 1,
   329       map (pair i) (map Token (String.tokens blank line) @ [Newline]) :: tss)
   330   in apsnd (flat o rev) (File.fold_lines split path (1, [])) end
   331 
   332 fun stopper i = Scan.stopper (K (i, EOF)) (fn (_, EOF) => true | _ => false)
   333 
   334 fun scan_err msg [] = "Boogie (at end of input): " ^ msg
   335   | scan_err msg ((i, _) :: _) = "Boogie (at line " ^ string_of_int i ^ "): " ^
   336       msg
   337 
   338 fun scan_fail msg = Scan.fail_with (scan_err msg)
   339 
   340 fun finite scan path =
   341   let val (i, ts) = tokenize path
   342   in
   343     (case Scan.error (Scan.finite (stopper i) scan) ts of
   344       (x, []) => x
   345     | (_, ts) => error (scan_err "unparsed input" ts))
   346   end
   347 
   348 fun read_int' s = (case read_int (explode s) of (i, []) => SOME i | _ => NONE)
   349 
   350 fun $$$ s = Scan.one (fn (_, Token s') => s = s' | _ => false)
   351 fun str st = Scan.some (fn (_, Token s) => SOME s | _ => NONE) st
   352 fun num st = Scan.some (fn (_, Token s) => read_int' s | _ => NONE) st
   353 
   354 fun scan_line key scan =
   355   $$$ key |-- scan --| Scan.one (fn (_, Newline) => true | _ => false)
   356 fun scan_line' key = scan_line key (Scan.succeed ())
   357 
   358 fun scan_count scan i =
   359   if i > 0 then scan ::: scan_count scan (i - 1) else Scan.succeed []
   360 
   361 fun scan_lookup kind tab key =
   362   (case Symtab.lookup tab key of
   363     SOME value => Scan.succeed value
   364   | NONE => scan_fail ("undefined " ^ kind ^ ": " ^ quote key))
   365 
   366 fun typ tds =
   367   let
   368     fun tp st =
   369      (scan_line' "bool" >> K @{typ bool} ||
   370       scan_line' "int" >> K @{typ int} ||
   371       scan_line "bv" num >> mk_wordT ||
   372       scan_line "type-con" (str -- num) :|-- (fn (name, arity) =>
   373         scan_lookup "type constructor" tds name -- scan_count tp arity >>
   374         Type) ||
   375       scan_line "array" num :|-- (fn arity =>
   376         scan_count tp (arity - 1) -- tp >> mk_arrayT) ||
   377       scan_fail "illegal type") st
   378   in tp end
   379 
   380 local
   381   fun mk_nary _ t [] = t
   382     | mk_nary f _ ts = uncurry (fold_rev f) (split_last ts)
   383 
   384   fun mk_distinct T ts =
   385     Const (@{const_name distinct}, HOLogic.listT T --> @{typ bool}) $ 
   386       HOLogic.mk_list T ts
   387 
   388   fun quant name f = scan_line name (num -- num -- num) >> pair f
   389   val quants =
   390     quant "forall" HOLogic.all_const ||
   391     quant "exists" HOLogic.exists_const ||
   392     scan_fail "illegal quantifier kind"
   393   fun mk_quant q (n, T) t = q T $ Term.absfree (n, T, t)
   394 
   395   val patternT = @{typ pattern}
   396   fun mk_pattern _ [] = raise TERM ("mk_pattern", [])
   397     | mk_pattern n [t] = Const (n, Term.fastype_of t --> patternT) $ t
   398     | mk_pattern n (t :: ts) =
   399         let val T = patternT --> Term.fastype_of t --> patternT
   400         in Const (@{const_name andpat}, T) $ mk_pattern n ts $ t end
   401   fun patt n c scan =
   402     scan_line n num :|-- scan_count scan >> (mk_pattern c)
   403   fun pattern scan =
   404     patt "pat" @{const_name pat} scan ||
   405     patt "nopat" @{const_name nopat} scan ||
   406     scan_fail "illegal pattern kind"
   407   fun mk_trigger [] t = t
   408     | mk_trigger ps t = @{term trigger} $ HOLogic.mk_list patternT ps $ t
   409 
   410   fun make_label (line, col) = Free (label_name line col, @{typ bool})
   411   fun labelled_by kind pos t = kind $ make_label pos $ t
   412   fun label offset =
   413     $$$ "pos" |-- num -- num >> (fn (line, col) =>
   414       if label_name line col = no_label_name then I
   415       else labelled_by @{term block_at} (line - offset, col)) ||
   416     $$$ "neg" |-- num -- num >> (fn (line, col) =>
   417       labelled_by @{term assert_at} (line - offset, col)) ||
   418     scan_fail "illegal label kind"
   419 
   420   fun mk_store ((m, k), v) =
   421     let
   422       val mT = Term.fastype_of m and kT = Term.fastype_of k
   423       val vT = Term.fastype_of v
   424     in Const (@{const_name fun_upd}, mT --> kT --> vT --> mT) $ m $ k $ v end
   425   
   426   fun mk_extract ((msb, lsb), t) =
   427     let
   428       val dT = Term.fastype_of t and rT = mk_wordT (msb - lsb)
   429       val nT = @{typ nat}
   430       val mk_nat_num = HOLogic.mk_number @{typ nat}
   431     in Const (@{const_name slice}, [nT, dT] ---> rT) $ mk_nat_num lsb $ t end
   432 
   433   fun mk_concat (t1, t2) =
   434     let
   435       val T1 = Term.fastype_of t1 and T2 = Term.fastype_of t2
   436       val U = mk_wordT (dest_wordT T1 + dest_wordT T2)
   437     in Const (@{const_name word_cat}, [T1, T2] ---> U) $ t1 $ t2 end
   438 
   439   fun unique_labels t =
   440     let
   441       fun names_of (@{term assert_at} $ Free (n, _) $ t) = cons n #> names_of t
   442         | names_of (t $ u) = names_of t #> names_of u
   443         | names_of (Abs (_, _, t)) = names_of t
   444         | names_of _ = I
   445       val nctxt = Name.make_context (duplicates (op =) (names_of t []))
   446 
   447       fun fresh (i, nctxt) = (position_prefix ^ string_of_int i, (i+1, nctxt))
   448       fun renamed n (i, nctxt) =
   449         yield_singleton Name.variants n nctxt ||> pair i
   450       fun mk_label (name, t) = @{term assert_at} $ Free (name, @{typ bool}) $ t
   451 
   452       fun unique t =
   453         (case t of
   454           @{term assert_at} $ Free (n, _) $ u =>
   455             if n = no_label_name
   456             then fresh ##>> unique u #>> mk_label
   457             else renamed n ##>> unique u #>> mk_label
   458         | u1 $ u2 => unique u1 ##>> unique u2 #>> (op $)
   459         | Abs (n, T, u) => unique u #>> (fn u' => Abs (n, T, u'))
   460         | _ => pair t)
   461     in fst (unique t (1, nctxt)) end
   462 
   463   val var_name = str >> prefix var_prefix
   464   val dest_var_name = unprefix var_prefix
   465   fun rename_variables t =
   466     let
   467       fun short_var_name n = short_name (dest_var_name n)
   468 
   469       val all_names = Term.add_free_names t []
   470       val (names, nctxt) =
   471         all_names
   472         |> map_filter (try (fn n => (n, short_var_name n)))
   473         |> split_list
   474         ||>> (fn names => Name.variants names (Name.make_context all_names))
   475         |>> Symtab.make o (op ~~)
   476 
   477       fun rename_free n = the_default n (Symtab.lookup names n)
   478       fun rename_abs n = yield_singleton Name.variants (short_var_name n)
   479 
   480       fun rename _ (Free (n, T)) = Free (rename_free n, T)
   481         | rename nctxt (Abs (n, T, t)) =
   482             let val (n', nctxt') = rename_abs n nctxt
   483             in Abs (n', T, rename nctxt' t) end
   484         | rename nctxt (t $ u) = rename nctxt t $ rename nctxt u
   485         | rename _ t = t
   486     in rename nctxt t end
   487 in
   488 fun expr offset tds fds =
   489   let
   490     fun binop t (u1, u2) = t $ u1 $ u2
   491     fun binexp s f = scan_line' s |-- exp -- exp >> f
   492 
   493     and exp st =
   494      (scan_line' "true" >> K @{term True} ||
   495       scan_line' "false" >> K @{term False} ||
   496       scan_line' "not" |-- exp >> HOLogic.mk_not ||
   497       scan_line "and" num :|-- scan_count exp >> 
   498         mk_nary (curry HOLogic.mk_conj) @{term True} ||
   499       scan_line "or" num :|-- scan_count exp >>
   500         mk_nary (curry HOLogic.mk_disj) @{term False} ||
   501       binexp "implies" (binop @{term "op -->"}) ||
   502       scan_line "distinct" num :|-- scan_count exp >>
   503         (fn [] => @{term True}
   504           | ts as (t :: _) => mk_distinct (Term.fastype_of t) ts) ||
   505       binexp "=" HOLogic.mk_eq ||
   506       scan_line "var" var_name -- typ tds >> Free ||
   507       scan_line "fun" (str -- num) :|-- (fn (name, arity) =>
   508         scan_lookup "constant" fds name -- scan_count exp arity >>
   509         Term.list_comb) ||
   510       quants :|-- (fn (q, ((n, k), i)) =>
   511         scan_count (scan_line "var" var_name -- typ tds) n --
   512         scan_count (pattern exp) k --
   513         scan_count (attribute offset tds fds) i --
   514         exp >> (fn (((vs, ps), _), t) =>
   515           fold_rev (mk_quant q) vs (mk_trigger ps t))) ||
   516       scan_line "label" (label offset) -- exp >> (fn (mk, t) => mk t) ||
   517       scan_line "int-num" num >> HOLogic.mk_number @{typ int} ||
   518       binexp "<" (binop @{term "op < :: int => _"}) ||
   519       binexp "<=" (binop @{term "op <= :: int => _"}) ||
   520       binexp ">" (binop @{term "op < :: int => _"} o swap) ||
   521       binexp ">=" (binop @{term "op <= :: int => _"} o swap) ||
   522       binexp "+" (binop @{term "op + :: int => _"}) ||
   523       binexp "-" (binop @{term "op - :: int => _"}) ||
   524       binexp "*" (binop @{term "op * :: int => _"}) ||
   525       binexp "/" (binop @{term boogie_div}) ||
   526       binexp "%" (binop @{term boogie_mod}) ||
   527       scan_line "select" num :|-- (fn arity =>
   528         exp -- (scan_count exp (arity - 1) >> HOLogic.mk_tuple) >> (op $)) ||
   529       scan_line "store" num :|-- (fn arity =>
   530         exp -- (scan_count exp (arity - 2) >> HOLogic.mk_tuple) -- exp >> 
   531           mk_store) ||
   532       scan_line "bv-num" (num -- num) >> (fn (size, i) =>
   533         HOLogic.mk_number (mk_wordT size) i) ||
   534       scan_line "bv-extract" (num -- num) -- exp >> mk_extract ||
   535       binexp "bv-concat" mk_concat ||
   536       scan_fail "illegal expression") st
   537   in exp >> (rename_variables o unique_labels) end
   538 
   539 and attribute offset tds fds =
   540   let
   541     val attr_val = 
   542       scan_line' "expr-attr" |-- expr offset tds fds >> TermValue ||
   543       scan_line "string-attr" (Scan.repeat1 str) >>
   544         (StringValue o space_implode " ") ||
   545       scan_fail "illegal attribute value"
   546   in
   547     scan_line "attribute" (str -- num) :|-- (fn (name, i) =>
   548       scan_count attr_val i >> pair name) ||
   549     scan_fail "illegal attribute"
   550   end
   551 end
   552 
   553 fun type_decls verbose = Scan.depend (fn thy => 
   554   Scan.repeat (scan_line "type-decl" (str -- num -- num) :|-- (fn (ty, i) =>
   555     scan_count (attribute 0 Symtab.empty Symtab.empty) i >> K ty)) >>
   556     (fn tys => declare_types verbose tys thy))
   557 
   558 fun fun_decls verbose tds = Scan.depend (fn thy =>
   559   Scan.repeat (scan_line "fun-decl" (str -- num -- num) :|--
   560     (fn ((name, arity), i) =>
   561       scan_count (typ tds) (arity - 1) -- typ tds --
   562       scan_count (attribute 0 tds Symtab.empty) i >> pair name)) >>
   563     (fn fns => declare_functions verbose fns thy))
   564 
   565 fun axioms verbose tds fds unique_axs = Scan.depend (fn thy =>
   566   Scan.repeat (scan_line "axiom" num :|-- (fn i =>
   567     expr 0 tds fds --| scan_count (attribute 0 tds fds) i)) >>
   568     (fn axs => (add_axioms verbose (unique_axs @ axs) thy, ())))
   569 
   570 fun var_decls tds fds = Scan.depend (fn thy =>
   571   Scan.repeat (scan_line "var-decl" (str -- num) :|-- (fn (_, i) =>
   572     typ tds -- scan_count (attribute 0 tds fds) i >> K ())) >> K (thy, ()))
   573 
   574 fun local_vc_offset offsets vc_name =
   575    Integer.add ~1 (the_default 1 (AList.lookup (op =) offsets vc_name))
   576 
   577 fun vcs verbose offsets tds fds = Scan.depend (fn thy =>
   578   Scan.repeat (scan_line "vc" (str -- num) :-- (fn (name, _) =>
   579     (expr (local_vc_offset offsets name) tds fds))) >> 
   580     (fn vcs => ((), add_vcs verbose vcs thy)))
   581 
   582 fun parse verbose offsets thy = Scan.pass thy
   583  (type_decls verbose :|-- (fn tds =>
   584   fun_decls verbose tds :|-- (fn (unique_axs, fds) =>
   585   axioms verbose tds fds unique_axs |--
   586   var_decls tds fds |--
   587   vcs verbose offsets tds fds)))
   588 
   589 fun load_b2i verbose offsets path thy = finite (parse verbose offsets thy) path
   590 
   591 end