(* Title: Pure/Syntax/standard_syntax.ML
Author: Makarius
Standard implementation of inner syntax operations.
*)
signature STANDARD_SYNTAX =
sig
val term_sorts: term -> (indexname * sort) list
val typ_of_term: (indexname -> sort) -> term -> typ
val decode_term: Proof.context ->
Position.reports * term Exn.result -> Position.reports * term Exn.result
val parse_ast_pattern: Proof.context -> string * string -> Ast.ast
end
structure Standard_Syntax: STANDARD_SYNTAX =
struct
(** decode parse trees **)
(* sort_of_term *)
fun sort_of_term tm =
let
fun err () = raise TERM ("sort_of_term: bad encoding of classes", [tm]);
fun class s = Lexicon.unmark_class s handle Fail _ => err ();
fun classes (Const (s, _)) = [class s]
| classes (Const ("_classes", _) $ Const (s, _) $ cs) = class s :: classes cs
| classes _ = err ();
fun sort (Const ("_topsort", _)) = []
| sort (Const (s, _)) = [class s]
| sort (Const ("_sort", _) $ cs) = classes cs
| sort _ = err ();
in sort tm end;
(* term_sorts *)
fun term_sorts tm =
let
val sort_of = sort_of_term;
fun add_env (Const ("_ofsort", _) $ Free (x, _) $ cs) =
insert (op =) ((x, ~1), sort_of cs)
| add_env (Const ("_ofsort", _) $ (Const ("_tfree", _) $ Free (x, _)) $ cs) =
insert (op =) ((x, ~1), sort_of cs)
| add_env (Const ("_ofsort", _) $ Var (xi, _) $ cs) =
insert (op =) (xi, sort_of cs)
| add_env (Const ("_ofsort", _) $ (Const ("_tvar", _) $ Var (xi, _)) $ cs) =
insert (op =) (xi, sort_of cs)
| add_env (Abs (_, _, t)) = add_env t
| add_env (t1 $ t2) = add_env t1 #> add_env t2
| add_env _ = I;
in add_env tm [] end;
(* typ_of_term *)
fun typ_of_term get_sort tm =
let
fun err () = raise TERM ("typ_of_term: bad encoding of type", [tm]);
fun typ_of (Free (x, _)) = TFree (x, get_sort (x, ~1))
| typ_of (Var (xi, _)) = TVar (xi, get_sort xi)
| typ_of (Const ("_tfree",_) $ (t as Free _)) = typ_of t
| typ_of (Const ("_tvar",_) $ (t as Var _)) = typ_of t
| typ_of (Const ("_ofsort", _) $ Free (x, _) $ _) = TFree (x, get_sort (x, ~1))
| typ_of (Const ("_ofsort", _) $ (Const ("_tfree",_) $ Free (x, _)) $ _) =
TFree (x, get_sort (x, ~1))
| typ_of (Const ("_ofsort", _) $ Var (xi, _) $ _) = TVar (xi, get_sort xi)
| typ_of (Const ("_ofsort", _) $ (Const ("_tvar",_) $ Var (xi, _)) $ _) =
TVar (xi, get_sort xi)
| typ_of (Const ("_dummy_ofsort", _) $ t) = TFree ("'_dummy_", sort_of_term t)
| typ_of t =
let
val (head, args) = Term.strip_comb t;
val a =
(case head of
Const (c, _) => (Lexicon.unmark_type c handle Fail _ => err ())
| _ => err ());
in Type (a, map typ_of args) end;
in typ_of tm end;
(* parsetree_to_ast *)
fun lookup_tr tab c = Option.map fst (Symtab.lookup tab c);
fun parsetree_to_ast ctxt constrain_pos trf parsetree =
let
val {get_class, get_type, markup_class, markup_type} = ProofContext.type_context ctxt;
val reports = Unsynchronized.ref ([]: Position.reports);
fun report pos = Position.reports reports [pos];
fun trans a args =
(case trf a of
NONE => Ast.mk_appl (Ast.Constant a) args
| SOME f => f ctxt args);
fun ast_of (Parser.Node ("_class_name", [Parser.Tip tok])) =
let
val c = get_class (Lexicon.str_of_token tok);
val _ = report (Lexicon.pos_of_token tok) markup_class c;
in Ast.Constant (Lexicon.mark_class c) end
| ast_of (Parser.Node ("_type_name", [Parser.Tip tok])) =
let
val c = get_type (Lexicon.str_of_token tok);
val _ = report (Lexicon.pos_of_token tok) markup_type c;
in Ast.Constant (Lexicon.mark_type c) end
| ast_of (Parser.Node ("_constrain_position", [pt as Parser.Tip tok])) =
if constrain_pos then
Ast.Appl [Ast.Constant "_constrain", ast_of pt,
Ast.Variable (Lexicon.encode_position (Lexicon.pos_of_token tok))]
else ast_of pt
| ast_of (Parser.Node (a, pts)) = trans a (map ast_of pts)
| ast_of (Parser.Tip tok) = Ast.Variable (Lexicon.str_of_token tok);
val ast = Exn.interruptible_capture ast_of parsetree;
in (! reports, ast) end;
(* ast_to_term *)
fun ast_to_term ctxt trf =
let
fun trans a args =
(case trf a of
NONE => Term.list_comb (Lexicon.const a, args)
| SOME f => f ctxt args);
fun term_of (Ast.Constant a) = trans a []
| term_of (Ast.Variable x) = Lexicon.read_var x
| term_of (Ast.Appl (Ast.Constant a :: (asts as _ :: _))) =
trans a (map term_of asts)
| term_of (Ast.Appl (ast :: (asts as _ :: _))) =
Term.list_comb (term_of ast, map term_of asts)
| term_of (ast as Ast.Appl _) = raise Ast.AST ("ast_to_term: malformed ast", [ast]);
in term_of end;
(* decode_term -- transform parse tree into raw term *)
fun markup_bound def id =
[Markup.properties [(if def then Markup.defN else Markup.refN, id)] Markup.bound];
fun decode_term _ (result as (_: Position.reports, Exn.Exn _)) = result
| decode_term ctxt (reports0, Exn.Result tm) =
let
val {get_const, get_free, markup_const, markup_free, markup_var} =
ProofContext.term_context ctxt;
val decodeT = typ_of_term (ProofContext.get_sort ctxt (term_sorts tm));
val reports = Unsynchronized.ref reports0;
fun report ps = Position.reports reports ps;
fun decode ps qs bs (Const ("_constrain", _) $ t $ typ) =
(case Syntax.decode_position_term typ of
SOME p => decode (p :: ps) qs bs t
| NONE => Type.constraint (decodeT typ) (decode ps qs bs t))
| decode ps qs bs (Const ("_constrainAbs", _) $ t $ typ) =
(case Syntax.decode_position_term typ of
SOME q => decode ps (q :: qs) bs t
| NONE => Type.constraint (decodeT typ --> dummyT) (decode ps qs bs t))
| decode _ qs bs (Abs (x, T, t)) =
let
val id = serial_string ();
val _ = report qs (markup_bound true) id;
in Abs (x, T, decode [] [] (id :: bs) t) end
| decode _ _ bs (t $ u) = decode [] [] bs t $ decode [] [] bs u
| decode ps _ _ (Const (a, T)) =
(case try Lexicon.unmark_fixed a of
SOME x => (report ps markup_free x; Free (x, T))
| NONE =>
let
val c =
(case try Lexicon.unmark_const a of
SOME c => c
| NONE => snd (get_const a));
val _ = report ps markup_const c;
in Const (c, T) end)
| decode ps _ _ (Free (a, T)) =
(case (get_free a, get_const a) of
(SOME x, _) => (report ps markup_free x; Free (x, T))
| (_, (true, c)) => (report ps markup_const c; Const (c, T))
| (_, (false, c)) =>
if Long_Name.is_qualified c
then (report ps markup_const c; Const (c, T))
else (report ps markup_free c; Free (c, T)))
| decode ps _ _ (Var (xi, T)) = (report ps markup_var xi; Var (xi, T))
| decode ps _ bs (t as Bound i) =
(case try (nth bs) i of
SOME id => (report ps (markup_bound false) id; t)
| NONE => t);
val tm' = Exn.interruptible_capture (fn () => decode [] [] [] tm) ();
in (! reports, tm') end;
(** parse **)
(* results *)
fun ambiguity_msg pos = "Parse error: ambiguous syntax" ^ Position.str_of pos;
fun proper_results results = map_filter (fn (y, Exn.Result x) => SOME (y, x) | _ => NONE) results;
fun failed_results results = map_filter (fn (y, Exn.Exn e) => SOME (y, e) | _ => NONE) results;
fun report ctxt = List.app (fn (pos, m) => Context_Position.report ctxt pos m);
fun report_result ctxt pos results =
(case (proper_results results, failed_results results) of
([], (reports, exn) :: _) => (report ctxt reports; reraise exn)
| ([(reports, x)], _) => (report ctxt reports; x)
| _ => error (ambiguity_msg pos));
(* parse_asts *)
fun parse_asts ctxt raw root (syms, pos) =
let
val {lexicon, gram, parse_ast_trtab, ...} = Syntax.rep_syntax (ProofContext.syn_of ctxt);
val toks = Lexicon.tokenize lexicon raw syms;
val _ = List.app (Lexicon.report_token ctxt) toks;
val pts = Parser.parse ctxt gram root (filter Lexicon.is_proper toks)
handle ERROR msg =>
error (msg ^
implode (map (Markup.markup Markup.report o Lexicon.reported_token_range ctxt) toks));
val len = length pts;
val limit = Config.get ctxt Syntax.ambiguity_limit;
val _ =
if len <= Config.get ctxt Syntax.ambiguity_level then ()
else if not (Config.get ctxt Syntax.ambiguity_enabled) then error (ambiguity_msg pos)
else
(Context_Position.if_visible ctxt warning (cat_lines
(("Ambiguous input" ^ Position.str_of pos ^
"\nproduces " ^ string_of_int len ^ " parse trees" ^
(if len <= limit then "" else " (" ^ string_of_int limit ^ " displayed)") ^ ":") ::
map (Pretty.string_of o Parser.pretty_parsetree) (take limit pts))));
val constrain_pos = not raw andalso Config.get ctxt Syntax.positions;
val parsetree_to_ast = parsetree_to_ast ctxt constrain_pos (lookup_tr parse_ast_trtab);
in map parsetree_to_ast pts end;
(* read_raw *)
fun read_raw ctxt root input =
let
val {parse_ruletab, parse_trtab, ...} = Syntax.rep_syntax (ProofContext.syn_of ctxt);
val norm = Ast.normalize ctxt (Symtab.lookup_list parse_ruletab);
val ast_to_term = ast_to_term ctxt (lookup_tr parse_trtab);
in
parse_asts ctxt false root input
|> (map o apsnd o Exn.maps_result) (norm #> Exn.interruptible_capture ast_to_term)
end;
(* read sorts *)
fun standard_parse_sort ctxt (syms, pos) =
read_raw ctxt "sort" (syms, pos)
|> report_result ctxt pos
|> sort_of_term;
(* read types *)
fun standard_parse_typ ctxt (syms, pos) =
read_raw ctxt "type" (syms, pos)
|> report_result ctxt pos
|> (fn t => typ_of_term (ProofContext.get_sort ctxt (term_sorts t)) t);
(* read terms -- brute-force disambiguation via type-inference *)
fun standard_parse_term check ctxt root (syms, pos) =
let
val results = read_raw ctxt root (syms, pos) |> map (decode_term ctxt);
val level = Config.get ctxt Syntax.ambiguity_level;
val limit = Config.get ctxt Syntax.ambiguity_limit;
val ambiguity = length (proper_results results);
fun ambig_msg () =
if ambiguity > 1 andalso ambiguity <= level then
"Got more than one parse tree.\n\
\Retry with smaller syntax_ambiguity_level for more information."
else "";
val results' =
if ambiguity > 1 then
(Par_List.map_name "Syntax.disambig" o apsnd o Exn.maps_result) check results
else results;
val reports' = fst (hd results');
val errs = map snd (failed_results results');
val checked = map snd (proper_results results');
val len = length checked;
val show_term = Syntax.string_of_term (Config.put Syntax.show_brackets true ctxt);
in
if len = 0 then
report_result ctxt pos
[(reports', Exn.Exn (Exn.EXCEPTIONS (ERROR (ambig_msg ()) :: errs)))]
else if len = 1 then
(if ambiguity > level then
Context_Position.if_visible ctxt warning
"Fortunately, only one parse tree is type correct.\n\
\You may still want to disambiguate your grammar or your input."
else (); report_result ctxt pos results')
else
report_result ctxt pos
[(reports', Exn.Exn (ERROR (cat_lines (ambig_msg () ::
(("Ambiguous input, " ^ string_of_int len ^ " terms are type correct" ^
(if len <= limit then "" else " (" ^ string_of_int limit ^ " displayed)") ^ ":") ::
map show_term (take limit checked))))))]
end;
(* standard operations *)
fun parse_failed ctxt pos msg kind =
cat_error msg ("Failed to parse " ^ kind ^
Markup.markup Markup.report (Context_Position.reported_text ctxt pos Markup.bad ""));
fun parse_sort ctxt text =
let
val (syms, pos) = Syntax.parse_token ctxt Markup.sort text;
val S = standard_parse_sort ctxt (syms, pos)
handle ERROR msg => parse_failed ctxt pos msg "sort";
in Type.minimize_sort (ProofContext.tsig_of ctxt) S end;
fun parse_typ ctxt text =
let
val (syms, pos) = Syntax.parse_token ctxt Markup.typ text;
val T = standard_parse_typ ctxt (syms, pos)
handle ERROR msg => parse_failed ctxt pos msg "type";
in T end;
fun parse_term T ctxt text =
let
val (T', _) = Type_Infer.paramify_dummies T 0;
val (markup, kind) =
if T' = propT then (Markup.prop, "proposition") else (Markup.term, "term");
val (syms, pos) = Syntax.parse_token ctxt markup text;
val default_root = Config.get ctxt Syntax.default_root;
val root =
(case T' of
Type (c, _) =>
if c <> "prop" andalso Type.is_logtype (ProofContext.tsig_of ctxt) c
then default_root else c
| _ => default_root);
fun check t = (Syntax.check_term ctxt (Type.constraint T' t); Exn.Result t)
handle exn as ERROR _ => Exn.Exn exn;
val t = standard_parse_term check ctxt root (syms, pos)
handle ERROR msg => parse_failed ctxt pos msg kind;
in t end;
(* parse_ast_pattern *)
fun parse_ast_pattern ctxt (root, str) =
let
val syn = ProofContext.syn_of ctxt;
fun constify (ast as Ast.Constant _) = ast
| constify (ast as Ast.Variable x) =
if Syntax.is_const syn x orelse Long_Name.is_qualified x then Ast.Constant x
else ast
| constify (Ast.Appl asts) = Ast.Appl (map constify asts);
val (syms, pos) = Syntax.read_token str;
in
parse_asts ctxt true root (syms, pos)
|> report_result ctxt pos
|> constify
end;
(** unparse **)
fun unparse_sort ctxt =
Syntax.standard_unparse_sort {extern_class = Type.extern_class (ProofContext.tsig_of ctxt)}
ctxt (ProofContext.syn_of ctxt);
fun unparse_typ ctxt =
let
val tsig = ProofContext.tsig_of ctxt;
val extern = {extern_class = Type.extern_class tsig, extern_type = Type.extern_type tsig};
in Syntax.standard_unparse_typ extern ctxt (ProofContext.syn_of ctxt) end;
fun unparse_term ctxt =
let
val tsig = ProofContext.tsig_of ctxt;
val syntax = ProofContext.syntax_of ctxt;
val consts = ProofContext.consts_of ctxt;
val extern =
{extern_class = Type.extern_class tsig,
extern_type = Type.extern_type tsig,
extern_const = Consts.extern consts};
in
Syntax.standard_unparse_term (Local_Syntax.idents_of syntax) extern ctxt
(Local_Syntax.syn_of syntax) (not (Pure_Thy.old_appl_syntax (ProofContext.theory_of ctxt)))
end;
(** install operations **)
val _ = Syntax.install_operations
{parse_sort = parse_sort,
parse_typ = parse_typ,
parse_term = parse_term dummyT,
parse_prop = parse_term propT,
unparse_sort = unparse_sort,
unparse_typ = unparse_typ,
unparse_term = unparse_term};
end;