# HG changeset patch
# User wenzelm
# Date 1176640317 -7200
# Node ID 7e6412e8d64bad7c874fa7963c10690b8548c8a6
# Parent  92f8e9a8df78696110482bbf751fcf0b1625e292
moved get_sort to sign.ML;
moved decode_types to Syntax/type_ext.ML;
moved mixfixT to Syntax/mixfix.ML;
proper infer_types, without decode/name lookup;
tuned;

diff -r 92f8e9a8df78 -r 7e6412e8d64b src/Pure/type_infer.ML
--- a/src/Pure/type_infer.ML	Sun Apr 15 14:31:56 2007 +0200
+++ b/src/Pure/type_infer.ML	Sun Apr 15 14:31:57 2007 +0200
@@ -2,62 +2,56 @@
     ID:         $Id$
     Author:     Stefan Berghofer and Markus Wenzel, TU Muenchen
 
-Type inference.
+Simple type inference.
 *)
 
 signature TYPE_INFER =
 sig
   val anyT: sort -> typ
   val logicT: typ
-  val mixfixT: Syntax.mixfix -> typ
   val polymorphicT: typ -> typ
-  val appl_error: Pretty.pp -> string -> term -> typ -> term -> typ -> string list
   val constrain: term -> typ -> term
   val param: int -> string * sort -> typ
   val paramify_dummies: typ -> int -> typ * int
-  val get_sort: Type.tsig -> (indexname -> sort option) -> (sort -> sort)
-    -> (indexname * sort) list -> indexname -> sort
-  val infer_types: Pretty.pp
-    -> Type.tsig -> (string -> typ option) -> (indexname -> typ option)
-    -> (indexname -> sort option) -> (string -> string) -> (typ -> typ)
-    -> (sort -> sort) -> Name.context -> bool -> typ list -> term list
-    -> term list * (indexname * typ) list
+  val appl_error: Pretty.pp -> string -> term -> typ -> term -> typ -> string list
+  val infer_types: Pretty.pp -> Type.tsig ->
+    (string -> typ option) -> (indexname -> typ option) ->
+    Name.context -> bool -> (term * typ) list -> (term * typ) list * (indexname * typ) list
 end;
 
 structure TypeInfer: TYPE_INFER =
 struct
 
 
-(** term encodings **)
+(** type parameters and constraints **)
 
-(*
-  Flavours of term encodings:
+fun anyT S = TFree ("'_dummy_", S);
+val logicT = anyT [];
 
-    parse trees (type term):
-      A very complicated structure produced by the syntax module's
-      read functions.  Encodes types and sorts as terms; may contain
-      explicit constraints and partial typing information (where
-      dummies serve as wildcards).
+(*indicate polymorphic Vars*)
+fun polymorphicT T = Type ("_polymorphic_", [T]);
 
-      Parse trees are INTERNAL! Users should never encounter them,
-      except in parse / print translation functions.
+fun constrain t T =
+  if T = dummyT then t
+  else Const ("_type_constraint_", T --> T) $ t;
+
+
+(* user parameters *)
 
-    raw terms (type term):
-      Provide the user interface to type inferences.  They may contain
-      partial type information (dummies are wildcards) or explicit
-      type constraints (introduced via constrain: term -> typ ->
-      term).
+fun is_param_default (x, _) = size x > 0 andalso ord x = ord "?";
+fun param i (x, S) = TVar (("?" ^ x, i), S);
+
+val paramify_dummies =
+  let
+    fun dummy S maxidx = (param (maxidx + 1) ("'dummy", S), maxidx + 1);
 
-      The type inference function also lets users specify a certain
-      subset of TVars to be treated as non-rigid inference parameters.
-
-    preterms (type preterm):
-      The internal representation for type inference.
-
-    well-typed term (type term):
-      Fully typed lambda terms to be accepted by appropriate
-      certification functions.
-*)
+    fun paramify (TFree ("'_dummy_", S)) maxidx = dummy S maxidx
+      | paramify (Type ("dummy", _)) maxidx = dummy [] maxidx
+      | paramify (Type (a, Ts)) maxidx =
+          let val (Ts', maxidx') = fold_map paramify Ts maxidx
+          in (Type (a, Ts'), maxidx') end
+      | paramify T maxidx = (T, maxidx);
+  in paramify end;
 
 
 
@@ -103,16 +97,6 @@
 
 (* pretyp_of *)
 
-fun anyT S = TFree ("'_dummy_", S);
-val logicT = anyT [];
-
-fun mixfixT (Binder _) = (logicT --> logicT) --> logicT
-  | mixfixT mx = replicate (Syntax.mixfix_args mx) logicT ---> logicT;
-
-
-(*indicate polymorphic Vars*)
-fun polymorphicT T = Type ("_polymorphic_", [T]);
-
 fun pretyp_of is_param typ params =
   let
     val params' = fold_atyps
@@ -151,11 +135,10 @@
       tm vparams;
     fun var_param xi = the (Vartab.lookup vparams' xi);
 
-
     val preT_of = pretyp_of is_param;
     fun polyT_of T = fst (pretyp_of (K true) T Vartab.empty);
 
-    fun constrain T t ps =
+    fun constraint T t ps =
       if T = dummyT then (t, ps)
       else
         let val (T', ps') = preT_of T ps
@@ -163,13 +146,13 @@
 
     fun pre_of (Const (c, T)) ps =
           (case const_type c of
-            SOME U => constrain T (PConst (c, polyT_of U)) ps
+            SOME U => constraint T (PConst (c, polyT_of U)) ps
           | NONE => raise TYPE ("No such constant: " ^ quote c, [], []))
       | pre_of (Var (xi, Type ("_polymorphic_", [T]))) ps = (PVar (xi, polyT_of T), ps)
-      | pre_of (Var (xi, T)) ps = constrain T (PVar (xi, var_param xi)) ps
-      | pre_of (Free (x, T)) ps = constrain T (PFree (x, var_param (x, ~1))) ps
+      | pre_of (Var (xi, T)) ps = constraint T (PVar (xi, var_param xi)) ps
+      | pre_of (Free (x, T)) ps = constraint T (PFree (x, var_param (x, ~1))) ps
       | pre_of (Const ("_type_constraint_", Type ("fun", [T, _])) $ t) ps =
-          uncurry (constrain T) (pre_of t ps)
+          pre_of t ps |-> constraint T
       | pre_of (Bound i) ps = (PBound i, ps)
       | pre_of (Abs (x, T, t)) ps =
           let
@@ -250,7 +233,6 @@
 
 exception NO_UNIFIER of string;
 
-
 fun unify pp tsig =
   let
 
@@ -310,6 +292,8 @@
 
 (** type inference **)
 
+(* appl_error *)
+
 fun appl_error pp why t T u U =
  ["Type error in application: " ^ why,
   "",
@@ -392,13 +376,27 @@
   in inf [] end;
 
 
-(* basic_infer_types *)
+(* infer_types *)
 
-fun basic_infer_types pp tsig const_type used freeze is_param ts Ts =
+fun infer_types pp tsig const_type var_type used freeze args =
   let
+    (*certify types*)
+    val certT = Type.cert_typ tsig;
+    val (raw_ts, raw_Ts) = split_list args;
+    val ts = map (Term.map_types certT) raw_ts;
+    val Ts = map certT raw_Ts;
+
+    (*constrain vars*)
+    val get_type = the_default dummyT o var_type;
+    val constrain_vars = Term.map_aterms
+      (fn Free (x, T) => constrain (Free (x, get_type (x, ~1))) T
+        | Var (xi, T) => constrain (Var (xi, get_type xi)) T
+        | t => t);
+
     (*convert to preterms/typs*)
     val (Ts', Tps) = fold_map (pretyp_of (K true)) Ts Vartab.empty;
-    val (ts', (vps, ps)) = fold_map (preterm_of const_type is_param) ts (Vartab.empty, Tps);
+    val (ts', (vps, ps)) =
+      fold_map (preterm_of const_type is_param_default o constrain_vars) ts (Vartab.empty, Tps);
 
     (*run type inference*)
     val tTs' = ListPair.map Constraint (ts', Ts');
@@ -415,118 +413,6 @@
       else (fn (x, S) => PTVar ((x, 0), S));
     val (final_Ts, final_ts) = typs_terms_of used mk_var "" (Ts', ts');
     val final_env = map (apsnd simple_typ_of) env;
-  in (final_ts, final_Ts, final_env) end;
-
-
-
-(** type inference **)
-
-(* user constraints *)
-
-fun constrain t T =
-  if T = dummyT then t
-  else Const ("_type_constraint_", T --> T) $ t;
-
-
-(* user parameters *)
-
-fun is_param (x, _) = size x > 0 andalso ord x = ord "?";
-fun param i (x, S) = TVar (("?" ^ x, i), S);
-
-val paramify_dummies =
-  let
-    fun dummy S maxidx = (param (maxidx + 1) ("'dummy", S), maxidx + 1);
-
-    fun paramify (TFree ("'_dummy_", S)) maxidx = dummy S maxidx
-      | paramify (Type ("dummy", _)) maxidx = dummy [] maxidx
-      | paramify (Type (a, Ts)) maxidx =
-          let val (Ts', maxidx') = fold_map paramify Ts maxidx
-          in (Type (a, Ts'), maxidx') end
-      | paramify T maxidx = (T, maxidx);
-  in paramify end;
-
-
-(* get sort constraints *)
-
-fun get_sort tsig def_sort map_sort raw_env =
-  let
-    fun eq ((xi, S), (xi', S')) =
-      Term.eq_ix (xi, xi') andalso Type.eq_sort tsig (S, S');
-
-    val env = distinct eq (map (apsnd map_sort) raw_env);
-    val _ = (case duplicates (eq_fst (op =)) env of [] => ()
-      | dups => error ("Inconsistent sort constraints for type variable(s) "
-          ^ commas_quote (map (Term.string_of_vname' o fst) dups)));
-
-    fun get xi =
-      (case (AList.lookup (op =) env xi, def_sort xi) of
-        (NONE, NONE) => Type.defaultS tsig
-      | (NONE, SOME S) => S
-      | (SOME S, NONE) => S
-      | (SOME S, SOME S') =>
-          if Type.eq_sort tsig (S, S') then S'
-          else error ("Sort constraint inconsistent with default for type variable " ^
-            quote (Term.string_of_vname' xi)));
-  in get end;
-
-
-(* decode_types -- transform parse tree into raw term *)
-
-fun decode_types tsig is_const def_type def_sort map_const map_type map_sort tm =
-  let
-    fun get_type xi = the_default dummyT (def_type xi);
-    fun is_free x = is_some (def_type (x, ~1));
-    val raw_env = Syntax.raw_term_sorts tm;
-    val sort_of = get_sort tsig def_sort map_sort raw_env;
-
-    val certT = Type.cert_typ tsig o map_type;
-    fun decodeT t = certT (Syntax.typ_of_term sort_of map_sort t);
-
-    fun decode (Const ("_constrain", _) $ t $ typ) =
-          constrain (decode t) (decodeT typ)
-      | decode (Const ("_constrainAbs", _) $ (Abs (x, T, t)) $ typ) =
-          if T = dummyT then Abs (x, decodeT typ, decode t)
-          else constrain (Abs (x, certT T, decode t)) (decodeT typ --> dummyT)
-      | decode (Abs (x, T, t)) = Abs (x, certT T, decode t)
-      | decode (t $ u) = decode t $ decode u
-      | decode (Const (x, T)) =
-          let val c = (case try (unprefix Syntax.constN) x of SOME c => c | NONE => map_const x)
-          in Const (c, certT T) end
-      | decode (Free (x, T)) =
-          let val c = map_const x in
-            if not (is_free x) andalso (is_const c orelse NameSpace.is_qualified c) then
-              Const (c, certT T)
-            else if T = dummyT then Free (x, get_type (x, ~1))
-            else constrain (Free (x, certT T)) (get_type (x, ~1))
-          end
-      | decode (Var (xi, T)) =
-          if T = dummyT then Var (xi, get_type xi)
-          else constrain (Var (xi, certT T)) (get_type xi)
-      | decode (t as Bound _) = t;
-  in decode tm end;
-
-
-(* infer_types *)
-
-(*Given [T1,...,Tn] and [t1,...,tn], ensure that the type of ti
-  unifies with Ti (for i=1,...,n).
-
-  tsig: type signature
-  const_type: name mapping and signature lookup
-  def_type: partial map from indexnames to types (constrains Frees and Vars)
-  def_sort: partial map from indexnames to sorts (constrains TFrees and TVars)
-  used: context of already used type variables
-  freeze: if true then generated parameters are turned into TFrees, else TVars*)
-
-fun infer_types pp tsig const_type def_type def_sort
-    map_const map_type map_sort used freeze pat_Ts raw_ts =
-  let
-    val pat_Ts' = map (Type.cert_typ tsig) pat_Ts;
-    val is_const = is_some o const_type;
-    val raw_ts' =
-      map (decode_types tsig is_const def_type def_sort map_const map_type map_sort) raw_ts;
-    val (ts, Ts, unifier) =
-      basic_infer_types pp tsig const_type used freeze is_param raw_ts' pat_Ts';
-  in (ts, unifier) end;
+  in (final_ts ~~ final_Ts, final_env) end;
 
 end;