modules Instantiate, Constant et Inductive

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@22 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 103 insertions, 0 deletions

diff --git a/kernel/instantiate.ml b/kernel/instantiate.ml
new file mode 100644
index 000000000..6302badc2
--- /dev/null
+++ b/kernel/instantiate.ml
@@ -0,0 +1,103 @@
+
+(* $Id$ *)
+
+open Pp
+open Util
+open Names
+open Generic
+open Term
+open Sign
+open Constant
+open Evd
+open Environ
+
+let is_id_inst ids args =
+  let is_id id = function
+    | VAR id' -> id = id'
+    | _ -> false
+  in
+  List.for_all2 is_id ids args
+
+let instantiate_constr ids c args =
+  if is_id_inst ids args then
+    c
+  else
+    replace_vars (List.combine ids (List.map make_substituend args)) c
+
+let instantiate_type ids tty args =
+  { body = instantiate_constr ids tty.body args;
+    typ = tty.typ }
+
+(* Constants. *)
+
+(* constant_type gives the type of a constant *)
+let constant_type env k =
+  let (sp,args) = destConst k in
+  let cb = lookup_constant sp env in
+  instantiate_type 
+    (ids_of_sign cb.const_hyps) cb.const_type (Array.to_list args)
+
+let constant_value env k =
+  let (sp,args) = destConst k in
+  let cb = lookup_constant sp env in
+  if not cb.const_opaque & defined_const env k then
+    match cb.const_body with
+      Some { contents = Cooked body } -> 
+        instantiate_constr 
+	  (ids_of_sign cb.const_hyps) body (Array.to_list args)
+    | Some { contents = Recipe _ } ->
+        anomalylabstrm "termenv__constant_value"
+          [< 'sTR "a transparent constant which was not cooked" >]
+    | None -> anomalylabstrm "termenv__constant_value"
+          [< 'sTR "a defined constant as no body." >]
+  else failwith "opaque"
+
+
+(* existential_type gives the type of an existential *)
+let existential_type env k = 
+  let (sp,args) = destConst k in
+  let evd = Evd.map (evar_map env) sp in
+  instantiate_constr 
+    (ids_of_sign evd.evar_hyps) evd.evar_concl.body (Array.to_list args)
+
+(* existential_value gives the value of a defined existential *)
+let existential_value env k =
+  let (sp,args) = destConst k in
+  if defined_const env k then
+    let evd = Evd.map (evar_map env) sp in
+    match evd.evar_body with
+      | EVAR_DEFINED c ->
+ 	  instantiate_constr (ids_of_sign evd.evar_hyps) c (Array.to_list args)
+      | _ -> anomalylabstrm "termenv__existential_value"
+            [< 'sTR"The existential variable code just registered a" ;
+               'sPC ; 'sTR"grave internal error." >]
+  else 
+    failwith "undefined existential"
+
+(* Constants or existentials. *)
+
+(* gives the value of a const *)
+let const_or_ex_value env = function
+  | DOPN (Const sp, _) as k -> 
+      if is_existential k then
+        existential_value env k
+      else 
+	constant_value env k
+  | _ -> invalid_arg "const_or_ex_value"
+
+(* gives the type of a const *)
+let const_or_ex_type env = function
+  | DOPN (Const sp, _) as k -> 
+      if is_existential k then
+	existential_type env k
+      else 
+	(constant_type env k).body
+  | _ -> invalid_arg "const_or_ex_type"
+
+let const_abst_opt_value env c =
+  match c with
+    | DOPN(Const sp,_) ->
+	if evaluable_const env c then Some (const_or_ex_value env c) else None
+    | DOPN(Abst sp,_) ->
+	if evaluable_abst env c then Some (abst_value env c) else None
+    | _ -> invalid_arg "const_abst_opt_value"