X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Ftactics%2FreductionTactics.ml;h=d34678e52cf95e426c917df1205ec9dd27100b54;hb=25ec5b95fe67bbdee888a8268b3772a394cd74a5;hp=18db1a302dab0a3cbec4849e32202ca0bc137b27;hpb=6cf15c86b051582032c794f7da8a325e31fc0480;p=helm.git diff --git a/helm/ocaml/tactics/reductionTactics.ml b/helm/ocaml/tactics/reductionTactics.ml index 18db1a302..d34678e52 100644 --- a/helm/ocaml/tactics/reductionTactics.ml +++ b/helm/ocaml/tactics/reductionTactics.ml @@ -25,11 +25,9 @@ open ProofEngineTypes -(* Note: this code is almost identical to PrimitiveTactics.change_tac and +(* Note: this code is almost identical to change_tac and * it could be unified by making the change function a callback *) -let reduction_tac ~reduction ~pattern - (proof,goal) -= +let reduction_tac ~reduction ~pattern (proof,goal) = let curi,metasenv,pbo,pty = proof in let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in let change where terms = @@ -81,41 +79,106 @@ let whd_tac ~pattern = mk_tactic (reduction_tac ~reduction:CicReduction.whd ~pattern);; let normalize_tac ~pattern = - mk_tactic (reduction_tac ~reduction:CicReduction.normalize ~pattern );; + mk_tactic (reduction_tac ~reduction:CicReduction.normalize ~pattern);; -let fold_tac ~reduction ~term ~pattern = -(* - let fold_tac ~reduction ~pattern:(hyp_patterns,goal_pattern) ~term (proof,goal) - = +exception NotConvertible + +(* Note: this code is almost identical to reduction_tac and +* it could be unified by making the change function a callback *) +(* CSC: with_what is parsed in the context of the goal, but it should replace + something that lives in a completely different context. Thus we + perform a delift + lift phase to move it in the right context. However, + in this way the tactic is less powerful than expected: with_what cannot + reference variables that are local to the term that is going to be + replaced. To fix this we should parse with_what in the context of the + term(s) to be replaced. *) +let change_tac ~pattern with_what = + let change_tac ~pattern ~with_what (proof, goal) = let curi,metasenv,pbo,pty = proof in - let metano,context,ty = CicUtil.lookup_meta goal metasenv in - let term' = reduction context term in - let replace = - ProofEngineReduction.replace ~equality:(=) ~what:[term'] ~with_what:[term] + let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in + let context_len = List.length context in + let change context'_len where terms = + if terms = [] then where + else + let terms, terms' = + List.split + (List.map + (fun (context_of_t, t) -> + let context_of_t_len = List.length context_of_t in + let with_what_in_context' = + if context_len > context'_len then + begin + let with_what,subst,metasenv' = + CicMetaSubst.delift_rels [] metasenv + (context_len - context'_len) with_what + in + assert (subst = []); + assert (metasenv = metasenv'); + with_what + end + else + with_what in + let with_what_in_context_of_t = + if context_of_t_len > context'_len then + CicSubstitution.lift (context_of_t_len - context'_len) + with_what_in_context' + else + with_what in + let _,u = + CicTypeChecker.type_of_aux' metasenv context_of_t with_what + CicUniv.empty_ugraph in + let b,_ = + CicReduction.are_convertible ~metasenv context_of_t t with_what u in + if b then + t, with_what_in_context_of_t + else + raise NotConvertible) terms) in - let ty' = replace ty in - let metasenv' = - let context' = - if also_in_hypotheses then - List.map - (function - Some (n,Cic.Decl t) -> Some (n,Cic.Decl (replace t)) - | Some (n,Cic.Def (t,None)) -> Some (n,Cic.Def ((replace t),None)) - | None -> None - | Some (_,Cic.Def (_,Some _)) -> assert false - ) context - else - context - in - List.map - (function - (n,_,_) when n = metano -> (metano,context',ty') - | _ as t -> t - ) metasenv - - in - (curi,metasenv',pbo,pty), [metano] + ProofEngineReduction.replace ~equality:(==) ~what:terms ~with_what:terms' + ~where:where in + let (selected_context,selected_ty) = + ProofEngineHelpers.select ~metasenv ~conjecture ~pattern in + let ty' = change context_len ty selected_ty in + let context' = + List.fold_right2 + (fun entry selected_entry context' -> + let context'_len = List.length context' in + match entry,selected_entry with + None,None -> None::context' + | Some (name,Cic.Decl ty),Some (`Decl selected_ty) -> + let ty' = change context'_len ty selected_ty in + Some (name,Cic.Decl ty')::context' + | Some (name,Cic.Def (bo,ty)),Some (`Def (selected_bo,selected_ty)) -> + let bo' = change context'_len bo selected_bo in + let ty' = + match ty,selected_ty with + None,None -> None + | Some ty,Some selected_ty -> + Some (change context'_len ty selected_ty) + | _,_ -> assert false + in + Some (name,Cic.Def (bo',ty'))::context' + | _,_ -> assert false + ) context selected_context [] in + let metasenv' = + List.map (function + | (n,_,_) when n = metano -> (metano,context',ty') + | _ as t -> t + ) metasenv + in + (curi,metasenv',pbo,pty), [metano] + in + mk_tactic (change_tac ~pattern ~with_what) + +let fold_tac ~reduction ~term ~pattern = + let fold_tac ~reduction ~term ~pattern:(wanted,hyps_pat,concl_pat) status = + assert (wanted = None); (* this should be checked syntactically *) + let proof,goal = status in + let _,metasenv,_,_ = proof in + let _,context,_ = CicUtil.lookup_meta goal metasenv in + let reduced_term = reduction context term in + apply_tactic + (change_tac ~pattern:(Some reduced_term,hyps_pat,concl_pat) term) status in - mk_tactic (fold_tac ~reduction ~pattern ~term) -*) assert false + mk_tactic (fold_tac ~reduction ~term ~pattern) ;;