HUGE COMMIT

1. when applying a functor F(X) := B to a module M, the obtained module
   is no longer B{X.t := M.t for all t}, but B{X.t := b where b is the
   body of t in M}. In principle it is now easy to fine tune the behaviour
   to choose whether b or M.t must be used. This change implies modifications
   both inside and outside the kernel.
2. for each object in the library it is now necessary to define the behaviour
   w.r.t. the substitution {X.t := b}. Notice that in many many cases the
   pre-existing behaviour w.r.t. the substitution {X.t := M.t} was broken
   (in the sense that it used to break several invariants). This commit
   fixes the behaviours for most of the objects, excluded
     a) coercions: a future commit should allow any term to be declared
        as a coercion; moreover the invariant that just a coercion path
        exists between two classes will be broken by the instantiation.
     b) global references when used as arguments of a few tactics/commands
   In all the other cases the behaviour implemented is the one that looks
   to me as the one expected by the user (if possible):
   [ terminology: not expanded (X.t := M.t) vs expanded (X.t := b) ]
     a) argument scopes: not expanded
     b) SYNTAXCONSTANT: expanded
     c) implicit arguments: not expanded
     d) coercions: expansion to be done (for now not expanded)
     e) concrete syntax tree for patterns: expanded
     f) concrete syntax tree for raw terms: expanded
     g) evaluable references (used by unfold, delta expansion, etc.): not
        expanded
     h) auto's hints: expanded when possible (i.e. when the expansion of the
        head of the pattern is rigid)
     i) realizers (for program extraction): nothing is done since the actual
        code does not look for the realizer of definitions with a body;
        however this solution is fragile.
     l) syntax and notation: expanded
     m) structures and canonical structures: an invariant says that no
        parameter can happear in them ==> the substitution always yelds the
        original term
     n) stuff related to V7 syntax: since this part of the code is doomed
        to disappear, I have made no effort to fix a reasonable semantics;
        not expanded is the default one applied
     o) RefArgTypes: to be understood. For now a warning is issued whether
        expanded != not expanded, and the not expanded solution is chosen.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@6555 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 57 insertions, 50 deletions

diff --git a/pretyping/pattern.ml b/pretyping/pattern.ml
index b091d797ad..6e06f978f2 100644
--- a/pretyping/pattern.ml
+++ b/pretyping/pattern.ml
@@ -63,56 +63,11 @@ let rec occur_meta_pattern = function
   | PMeta _ | PSoApp _ -> true
   | PEvar _ | PVar _ | PRef _ | PRel _ | PSort _ | PFix _ | PCoFix _ -> false
 
-let rec subst_pattern subst pat = match pat with
-  | PRef ref ->
-      let ref' = subst_global subst ref in
-	if ref' == ref then pat else 
-	  PRef ref'
-  | PVar _ 
-  | PEvar _
-  | PRel _ -> pat
-  | PApp (f,args) ->
-      let f' = subst_pattern subst f in 
-      let args' = array_smartmap (subst_pattern subst) args in
-	if f' == f && args' == args then pat else
-	  PApp (f',args')
-  | PSoApp (i,args) ->
-      let args' = list_smartmap (subst_pattern subst) args in
-	if args' == args then pat else
-	  PSoApp (i,args')
-  | PLambda (name,c1,c2) ->
-      let c1' = subst_pattern subst c1 in
-      let c2' = subst_pattern subst c2 in
-	if c1' == c1 && c2' == c2 then pat else
-	  PLambda (name,c1',c2')
-  | PProd (name,c1,c2) ->
-      let c1' = subst_pattern subst c1 in
-      let c2' = subst_pattern subst c2 in
-	if c1' == c1 && c2' == c2 then pat else
-	  PProd (name,c1',c2')
-  | PLetIn (name,c1,c2) ->
-      let c1' = subst_pattern subst c1 in
-      let c2' = subst_pattern subst c2 in
-	if c1' == c1 && c2' == c2 then pat else
-	  PLetIn (name,c1',c2')
-  | PSort _ 
-  | PMeta _ -> pat
-  | PCase (cs,typ, c, branches) -> 
-      let typ' = option_smartmap (subst_pattern subst) typ in 
-      let c' = subst_pattern subst c in
-      let branches' = array_smartmap (subst_pattern subst) branches in
-	if typ' == typ && c' == c && branches' == branches then pat else
-	  PCase(cs,typ', c', branches') 
-  | PFix fixpoint ->
-      let cstr = mkFix fixpoint in
-      let fixpoint' = destFix (subst_mps subst cstr) in
-	if fixpoint' == fixpoint then pat else
-	  PFix fixpoint'
-  | PCoFix cofixpoint ->
-      let cstr = mkCoFix cofixpoint in
-      let cofixpoint' = destCoFix (subst_mps subst cstr) in
-	if cofixpoint' == cofixpoint then pat else
-	  PCoFix cofixpoint'
+type constr_label =
+  | ConstNode of constant
+  | IndNode of inductive
+  | CstrNode of constructor
+  | VarNode of identifier
 
 exception BoundPattern;;
 
@@ -177,6 +132,58 @@ let rec inst lvar = function
   | (PFix _ | PCoFix _ as r) ->
       error ("Not instantiable pattern")
 
+let rec subst_pattern subst pat = match pat with
+  | PRef ref ->
+      let ref',t = subst_global subst ref in
+	if ref' == ref then pat else
+	 pattern_of_constr t
+  | PVar _ 
+  | PEvar _
+  | PRel _ -> pat
+  | PApp (f,args) ->
+      let f' = subst_pattern subst f in 
+      let args' = array_smartmap (subst_pattern subst) args in
+	if f' == f && args' == args then pat else
+	  PApp (f',args')
+  | PSoApp (i,args) ->
+      let args' = list_smartmap (subst_pattern subst) args in
+	if args' == args then pat else
+	  PSoApp (i,args')
+  | PLambda (name,c1,c2) ->
+      let c1' = subst_pattern subst c1 in
+      let c2' = subst_pattern subst c2 in
+	if c1' == c1 && c2' == c2 then pat else
+	  PLambda (name,c1',c2')
+  | PProd (name,c1,c2) ->
+      let c1' = subst_pattern subst c1 in
+      let c2' = subst_pattern subst c2 in
+	if c1' == c1 && c2' == c2 then pat else
+	  PProd (name,c1',c2')
+  | PLetIn (name,c1,c2) ->
+      let c1' = subst_pattern subst c1 in
+      let c2' = subst_pattern subst c2 in
+	if c1' == c1 && c2' == c2 then pat else
+	  PLetIn (name,c1',c2')
+  | PSort _ 
+  | PMeta _ -> pat
+  | PCase (cs,typ, c, branches) -> 
+      let typ' = option_smartmap (subst_pattern subst) typ in 
+      let c' = subst_pattern subst c in
+      let branches' = array_smartmap (subst_pattern subst) branches in
+	if typ' == typ && c' == c && branches' == branches then pat else
+	  PCase(cs,typ', c', branches') 
+  | PFix fixpoint ->
+      let cstr = mkFix fixpoint in
+      let fixpoint' = destFix (subst_mps subst cstr) in
+	if fixpoint' == fixpoint then pat else
+	  PFix fixpoint'
+  | PCoFix cofixpoint ->
+      let cstr = mkCoFix cofixpoint in
+      let cofixpoint' = destCoFix (subst_mps subst cstr) in
+	if cofixpoint' == cofixpoint then pat else
+	  PCoFix cofixpoint'
+
+
 let instantiate_pattern = inst
 
 let rec pat_of_raw metas vars = function