path: root/kernel/vconv.ml

open Names
open Declarations
open Term
open Environ
open Conv_oracle
open Reduction 
open Closure
open Vm
open Csymtable 
open Univ

let val_of_constr env c =
  val_of_constr (pre_env env) c

(* Test la structure des piles *)

let compare_zipper z1 z2 =
  match z1, z2 with
  | Zapp args1, Zapp args2 -> nargs args1 = nargs args2
  | Zfix(f1,args1), Zfix(f2,args2) ->  nargs args1 = nargs args2
  | Zswitch _, Zswitch _ -> true
  | _ , _ -> false

let rec compare_stack stk1 stk2 =
  match stk1, stk2 with
  | [], [] -> true
  | z1::stk1, z2::stk2 ->
      if compare_zipper z1 z2 then compare_stack stk1 stk2
      else false
  | _, _ -> false 

(* Conversion *)
let conv_vect fconv vect1 vect2 cu =
  let n = Array.length vect1 in
  if n = Array.length vect2 then
    let rcu = ref cu in
    for i = 0 to n - 1 do
      rcu := fconv vect1.(i) vect2.(i) !rcu
    done;
    !rcu
  else raise NotConvertible

let infos = ref (create_clos_infos betaiotazeta Environ.empty_env)

let rec conv_val pb k v1 v2 cu = 
  if v1 == v2 then cu 
  else conv_whd pb k (whd_val v1) (whd_val v2) cu
    
and conv_whd pb k whd1 whd2 cu =  
  match whd1, whd2 with
  | Vsort s1, Vsort s2 -> sort_cmp pb s1 s2 cu 
  | Vprod p1, Vprod p2 ->
      let cu = conv_val CONV k (dom p1) (dom p2) cu in
      conv_fun pb k (codom p1) (codom p2) cu
  | Vfun f1, Vfun f2 -> conv_fun CONV k f1 f2 cu
  | Vfix (f1,None), Vfix (f2,None) -> conv_fix k f1 f2 cu
  | Vfix (f1,Some args1), Vfix(f2,Some args2) ->
      if nargs args1 <> nargs args2 then raise NotConvertible
      else conv_arguments k args1 args2 (conv_fix k f1 f2 cu)
  | Vcofix (cf1,_,None), Vcofix (cf2,_,None) -> conv_cofix k cf1 cf2 cu
  | Vcofix (cf1,_,Some args1), Vcofix (cf2,_,Some args2) ->	
      if nargs args1 <> nargs args2 then raise NotConvertible
      else conv_arguments k args1 args2 (conv_cofix k cf1 cf2 cu)
  | Vconstr_const i1, Vconstr_const i2 -> 
      if i1 = i2 then cu else raise NotConvertible 
  | Vconstr_block b1, Vconstr_block b2 ->
      let sz = bsize b1 in
      if btag b1 = btag b2 && sz = bsize b2 then
	let rcu = ref cu in
	for i = 0 to sz - 1 do
	  rcu := conv_val CONV k (bfield b1 i) (bfield b2 i) !rcu
	done;
	!rcu
      else raise NotConvertible
  | Vatom_stk(a1,stk1), Vatom_stk(a2,stk2) -> 
      conv_atom pb k a1 stk1 a2 stk2 cu
  | _, Vatom_stk(Aiddef(_,v),stk) -> 
      conv_whd pb k whd1 (force_whd v stk) cu
  | Vatom_stk(Aiddef(_,v),stk), _ -> 
      conv_whd pb k (force_whd v stk) whd2 cu
  | _, _ -> raise NotConvertible

and conv_atom pb k a1 stk1 a2 stk2 cu =
  match a1, a2 with
  | Aind (kn1,i1), Aind(kn2,i2) ->
      if mind_equiv_infos !infos (kn1,i1) (kn2,i2) && compare_stack stk1 stk2
      then
	conv_stack k stk1 stk2 cu
      else raise NotConvertible
  | Aid ik1, Aid ik2 -> 
      if ik1 = ik2 && compare_stack stk1 stk2 then 
	conv_stack k stk1 stk2 cu 
      else raise NotConvertible
  | Aiddef(ik1,v1), Aiddef(ik2,v2) ->
      begin
	try
	  if ik1 = ik2 && compare_stack stk1 stk2 then
	    conv_stack k stk1 stk2 cu 
	  else raise NotConvertible
	with NotConvertible ->
	  if oracle_order ik1 ik2 then             
            conv_whd pb k (whd_stack v1 stk1) (Vatom_stk(a2,stk2)) cu
          else conv_whd pb k (Vatom_stk(a1,stk1)) (whd_stack v2 stk2) cu
      end
  | Aiddef(ik1,v1), _ ->
      conv_whd pb k (force_whd v1 stk1) (Vatom_stk(a2,stk2)) cu
  | _, Aiddef(ik2,v2) ->
      conv_whd pb k (Vatom_stk(a1,stk1)) (force_whd v2 stk2) cu
  | _, _ -> raise NotConvertible 
	
and conv_stack k stk1 stk2 cu =
  match stk1, stk2 with
  | [], [] -> cu
  | Zapp args1 :: stk1, Zapp args2 :: stk2 ->
      conv_stack k stk1 stk2 (conv_arguments k args1 args2 cu) 
  | Zfix(f1,args1) :: stk1, Zfix(f2,args2) :: stk2 ->
      conv_stack k stk1 stk2 
	(conv_arguments k args1 args2 (conv_fix k f1 f2 cu))
  | Zswitch sw1 :: stk1, Zswitch sw2 :: stk2 ->
      if check_switch sw1 sw2 then
	let vt1,vt2 = type_of_switch sw1, type_of_switch sw2 in
	let rcu = ref (conv_val CONV k vt1 vt2 cu) in
	let b1, b2 = branch_of_switch k sw1, branch_of_switch k sw2 in
	for i = 0 to Array.length b1 - 1 do
	  rcu := 
	    conv_val CONV (k + fst b1.(i)) (snd b1.(i)) (snd b2.(i)) !rcu
	done;
	conv_stack k stk1 stk2 !rcu
      else raise NotConvertible
  | _, _ -> raise NotConvertible

and conv_fun pb k f1 f2 cu =
  if f1 == f2 then cu
  else
    let arity,b1,b2 = decompose_vfun2 k f1 f2 in
    conv_val pb (k+arity) b1 b2 cu

and conv_fix k f1 f2 cu =
  if f1 == f2 then cu 
  else
    if check_fix f1 f2 then
      let bf1, tf1 = reduce_fix k f1 in
      let bf2, tf2 = reduce_fix k f2 in
      let cu = conv_vect (conv_val CONV k) tf1 tf2 cu in
      conv_vect (conv_fun CONV (k + Array.length tf1)) bf1 bf2 cu
    else raise NotConvertible

and conv_cofix k cf1 cf2 cu =
  if cf1 == cf2 then cu
  else
    if check_cofix cf1 cf2 then
      let bcf1, tcf1 = reduce_cofix k cf1 in
      let bcf2, tcf2 = reduce_cofix k cf2 in
      let cu = conv_vect (conv_val CONV k) tcf1 tcf2 cu in
      conv_vect (conv_val CONV (k + Array.length tcf1)) bcf1 bcf2 cu
    else raise NotConvertible

and conv_arguments k args1 args2 cu =
  if args1 == args2 then cu
  else
    let n = nargs args1 in
    if n = nargs args2 then
      let rcu = ref cu in
      for i = 0 to n - 1 do
	rcu := conv_val CONV k (arg args1 i) (arg args2 i) !rcu
      done;
      !rcu
    else raise NotConvertible

let rec conv_eq pb t1 t2 cu =
  if t1 == t2 then cu 
  else
    match kind_of_term t1, kind_of_term t2 with
    | Rel n1, Rel n2 -> 
	if n1 = n2 then cu else raise NotConvertible
    | Meta m1, Meta m2 ->
	if m1 = m2 then cu else raise NotConvertible
    | Var id1, Var id2 -> 
	if id1 = id2 then cu else raise NotConvertible
    | Sort s1, Sort s2 -> sort_cmp pb s1 s2 cu
    | Cast (c1,_,_), _ -> conv_eq pb c1 t2 cu
    | _, Cast (c2,_,_) -> conv_eq pb t1 c2 cu
    | Prod (_,t1,c1), Prod (_,t2,c2) -> 
	conv_eq pb c1 c2 (conv_eq CONV t1 t2 cu)
    | Lambda (_,t1,c1), Lambda (_,t2,c2) -> conv_eq CONV c1 c2 cu
    | LetIn (_,b1,t1,c1), LetIn (_,b2,t2,c2) -> 
	conv_eq pb c1 c2 (conv_eq CONV b1 b2 cu)
    | App (c1,l1), App (c2,l2) ->
	conv_eq_vect l1 l2 (conv_eq CONV c1 c2 cu)
    | Evar (e1,l1), Evar (e2,l2) ->
	if e1 = e2 then conv_eq_vect l1 l2 cu
	else raise NotConvertible
    | Const c1, Const c2 -> 
	if c1 = c2 then cu else raise NotConvertible
    | Ind c1, Ind c2 -> 
	if c1 = c2 then cu else raise NotConvertible
    | Construct c1, Construct c2 -> 
	if c1 = c2 then cu else raise NotConvertible
    | Case (_,p1,c1,bl1), Case (_,p2,c2,bl2) ->
	let pcu = conv_eq CONV p1 p2 cu in
	let ccu = conv_eq CONV c1 c2 pcu in
	conv_eq_vect bl1 bl2 ccu
    | Fix (ln1,(_,tl1,bl1)), Fix (ln2,(_,tl2,bl2)) ->
	if ln1 = ln2 then conv_eq_vect tl1 tl2 (conv_eq_vect bl1 bl2 cu)
	else raise NotConvertible
    | CoFix(ln1,(_,tl1,bl1)), CoFix(ln2,(_,tl2,bl2)) ->	
	if ln1 = ln2 then conv_eq_vect tl1 tl2 (conv_eq_vect bl1 bl2 cu)
	else raise NotConvertible
    | _ -> raise NotConvertible

and conv_eq_vect vt1 vt2 cu =
  let len = Array.length vt1 in
  if len = Array.length vt2 then
    let rcu = ref cu in
    for i = 0 to len-1 do
      rcu := conv_eq CONV vt1.(i) vt2.(i) !rcu
    done; !rcu
  else raise NotConvertible
      
let vconv pb env t1 t2 =
  let cu =
    try conv_eq pb t1 t2 Constraint.empty
    with NotConvertible ->
      infos := create_clos_infos betaiotazeta env;
      let v1 = val_of_constr env t1 in
      let v2 = val_of_constr env t2 in
      let cu = conv_val pb (nb_rel env) v1 v2 Constraint.empty in
      cu
  in cu
    
let _ = Reduction.set_vm_conv vconv

let use_vm = ref false

let set_use_vm b =
  use_vm := b;
  if b then Reduction.set_default_conv vconv
  else Reduction.set_default_conv Reduction.conv_cmp
      
let use_vm _ = !use_vm