src/Pure/theory.ML

+(*  Title:      Pure/theory.ML
+    ID:         $Id$
+    Author:     Lawrence C Paulson and Markus Wenzel
+    Copyright   1996  University of Cambridge
+
+Theories
+*)
+
+signature THEORY =
+  sig
+  type theory
+  exception THEORY of string * theory list
+  val rep_theory        : theory ->
+    {sign: Sign.sg, new_axioms: term Symtab.table, parents: theory list}
+  val sign_of           : theory -> Sign.sg
+  val syn_of            : theory -> Syntax.syntax
+  val stamps_of_thy     : theory -> string ref list
+  val parents_of        : theory -> theory list
+  val subthy            : theory * theory -> bool
+  val eq_thy            : theory * theory -> bool
+  val proto_pure_thy    : theory
+  val pure_thy          : theory
+  val cpure_thy         : theory
+  (*theory primitives*)
+  val add_classes     : (class * class list) list -> theory -> theory
+  val add_classrel    : (class * class) list -> theory -> theory
+  val add_defsort     : sort -> theory -> theory
+  val add_types       : (string * int * mixfix) list -> theory -> theory
+  val add_tyabbrs     : (string * string list * string * mixfix) list
+    -> theory -> theory
+  val add_tyabbrs_i   : (string * string list * typ * mixfix) list
+    -> theory -> theory
+  val add_arities     : (string * sort list * sort) list -> theory -> theory
+  val add_consts      : (string * string * mixfix) list -> theory -> theory
+  val add_consts_i    : (string * typ * mixfix) list -> theory -> theory
+  val add_syntax      : (string * string * mixfix) list -> theory -> theory
+  val add_syntax_i    : (string * typ * mixfix) list -> theory -> theory
+  val add_trfuns      :
+    (string * (Syntax.ast list -> Syntax.ast)) list *
+    (string * (term list -> term)) list *
+    (string * (term list -> term)) list *
+    (string * (Syntax.ast list -> Syntax.ast)) list -> theory -> theory
+  val add_trrules     : (string * string)Syntax.trrule list -> theory -> theory
+  val add_trrules_i   : Syntax.ast Syntax.trrule list -> theory -> theory
+  val cert_axm          : Sign.sg -> string * term -> string * term
+  val read_axm          : Sign.sg -> string * string -> string * term
+  val inferT_axm        : Sign.sg -> string * term -> string * term
+  val add_axioms      : (string * string) list -> theory -> theory
+  val add_axioms_i    : (string * term) list -> theory -> theory
+  val add_thyname     : string -> theory -> theory
+
+  val merge_theories    : theory * theory -> theory
+  val merge_thy_list    : bool -> theory list -> theory
+end;
+
+
+structure Theory : THEORY =
+struct
+(*** Theories ***)
+
+datatype theory =
+  Theory of {
+    sign: Sign.sg,
+    new_axioms: term Symtab.table,
+    parents: theory list};
+
+fun rep_theory (Theory args) = args;
+
+(*errors involving theories*)
+exception THEORY of string * theory list;
+
+
+val sign_of = #sign o rep_theory;
+val syn_of = #syn o Sign.rep_sg o sign_of;
+
+(*stamps associated with a theory*)
+val stamps_of_thy = #stamps o Sign.rep_sg o sign_of;
+
+(*return the immediate ancestors*)
+val parents_of = #parents o rep_theory;
+
+
+(*compare theories*)
+val subthy = Sign.subsig o pairself sign_of;
+val eq_thy = Sign.eq_sg o pairself sign_of;
+
+
+(* the Pure theories *)
+
+val proto_pure_thy =
+  Theory {sign = Sign.proto_pure, new_axioms = Symtab.null, parents = []};
+
+val pure_thy =
+  Theory {sign = Sign.pure, new_axioms = Symtab.null, parents = []};
+
+val cpure_thy =
+  Theory {sign = Sign.cpure, new_axioms = Symtab.null, parents = []};
+
+
+
+(** extend theory **)
+
+fun err_dup_axms names =
+  error ("Duplicate axiom name(s) " ^ commas_quote names);
+
+fun ext_thy (thy as Theory {sign, new_axioms, parents}) sign1 new_axms =
+  let
+    val draft = Sign.is_draft sign;
+    val new_axioms1 =
+      Symtab.extend_new (if draft then new_axioms else Symtab.null, new_axms)
+        handle Symtab.DUPS names => err_dup_axms names;
+    val parents1 = if draft then parents else [thy];
+  in
+    Theory {sign = sign1, new_axioms = new_axioms1, parents = parents1}
+  end;
+
+
+(* extend signature of a theory *)
+
+fun ext_sg extfun decls (thy as Theory {sign, ...}) =
+  ext_thy thy (extfun decls sign) [];
+
+val add_classes   = ext_sg Sign.add_classes;
+val add_classrel  = ext_sg Sign.add_classrel;
+val add_defsort   = ext_sg Sign.add_defsort;
+val add_types     = ext_sg Sign.add_types;
+val add_tyabbrs   = ext_sg Sign.add_tyabbrs;
+val add_tyabbrs_i = ext_sg Sign.add_tyabbrs_i;
+val add_arities   = ext_sg Sign.add_arities;
+val add_consts    = ext_sg Sign.add_consts;
+val add_consts_i  = ext_sg Sign.add_consts_i;
+val add_syntax    = ext_sg Sign.add_syntax;
+val add_syntax_i  = ext_sg Sign.add_syntax_i;
+val add_trfuns    = ext_sg Sign.add_trfuns;
+val add_trrules   = ext_sg Sign.add_trrules;
+val add_trrules_i = ext_sg Sign.add_trrules_i;
+val add_thyname   = ext_sg Sign.add_name;
+
+
+(* prepare axioms *)
+
+fun err_in_axm name =
+  error ("The error(s) above occurred in axiom " ^ quote name);
+
+fun no_vars tm =
+  if null (term_vars tm) andalso null (term_tvars tm) then tm
+  else error "Illegal schematic variable(s) in term";
+
+fun cert_axm sg (name, raw_tm) =
+  let
+    val (t, T, _) = Sign.certify_term sg raw_tm
+      handle TYPE arg => error (Sign.exn_type_msg sg arg)
+	   | TERM (msg, _) => error msg;
+  in
+    assert (T = propT) "Term not of type prop";
+    (name, no_vars t)
+  end
+  handle ERROR => err_in_axm name;
+
+(*Some duplication of code with read_def_cterm*)
+fun read_axm sg (name, str) = 
+  let val ts = Syntax.read (#syn (Sign.rep_sg sg)) propT str;
+      val (_, t, _) =
+          Sign.infer_types sg (K None) (K None) [] true (ts,propT);
+  in cert_axm sg (name,t) end;
+
+fun inferT_axm sg (name, pre_tm) =
+  let val t = #2(Sign.infer_types sg (K None) (K None) [] true
+                                     ([pre_tm], propT))
+  in  (name, no_vars t) end
+  handle ERROR => err_in_axm name;
+
+
+(* extend axioms of a theory *)
+
+fun ext_axms prep_axm axms (thy as Theory {sign, ...}) =
+  let
+    val sign1 = Sign.make_draft sign;
+    val axioms = map (apsnd (Term.compress_term o Logic.varify) o 
+		      prep_axm sign) 
+	         axms;
+  in
+    ext_thy thy sign1 axioms
+  end;
+
+val add_axioms = ext_axms read_axm;
+val add_axioms_i = ext_axms cert_axm;
+
+
+
+(** merge theories **)
+
+fun merge_thy_list mk_draft thys =
+  let
+    fun is_union thy = forall (fn t => subthy (t, thy)) thys;
+    val is_draft = Sign.is_draft o sign_of;
+
+    fun add_sign (sg, Theory {sign, ...}) =
+      Sign.merge (sg, sign) handle TERM (msg, _) => error msg;
+  in
+    (case (find_first is_union thys, exists is_draft thys) of
+      (Some thy, _) => thy
+    | (None, true) => raise THEORY ("Illegal merge of draft theories", thys)
+    | (None, false) => Theory {
+        sign =
+          (if mk_draft then Sign.make_draft else I)
+          (foldl add_sign (Sign.proto_pure, thys)),
+        new_axioms = Symtab.null,
+        parents = thys})
+  end;
+
+fun merge_theories (thy1, thy2) = merge_thy_list false [thy1, thy2];
+
+
+end;
+
+open Theory;