author | paulson |
Sat, 08 Feb 2003 16:05:33 +0100 | |
changeset 13812 | 91713a1915ee |
parent 13645 | 430310b12c5b |
child 13891 | ae9a2a433388 |
permissions | -rw-r--r-- |
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(* Title: Pure/pattern.ML |
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ID: $Id$ |
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Author: Tobias Nipkow, Christine Heinzelmann, and Stefan Berghofer |
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License: GPL (GNU GENERAL PUBLIC LICENSE) |
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Unification of Higher-Order Patterns. |
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See also: |
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Tobias Nipkow. Functional Unification of Higher-Order Patterns. |
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In Proceedings of the 8th IEEE Symposium Logic in Computer Science, 1993. |
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TODO: optimize red by special-casing it |
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*) |
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infix aeconv; |
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signature PATTERN = |
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sig |
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type type_sig |
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type sg |
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type env |
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val trace_unify_fail : bool ref |
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val aeconv : term * term -> bool |
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val eta_contract : term -> term |
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val beta_eta_contract : term -> term |
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val eta_contract_atom : term -> term |
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val match : type_sig -> term * term |
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-> (indexname*typ)list * (indexname*term)list |
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val first_order_match : type_sig -> term * term |
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-> (indexname*typ)list * (indexname*term)list |
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val matches : type_sig -> term * term -> bool |
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val matches_subterm : type_sig -> term * term -> bool |
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val unify : sg * env * (term * term)list -> env |
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val first_order : term -> bool |
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val pattern : term -> bool |
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val rewrite_term : type_sig -> (term * term) list -> (term -> term option) list |
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-> term -> term |
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exception Unif |
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exception MATCH |
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exception Pattern |
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end; |
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structure Pattern : PATTERN = |
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struct |
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type type_sig = Type.type_sig |
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type sg = Sign.sg |
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type env = Envir.env |
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exception Unif; |
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exception Pattern; |
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val trace_unify_fail = ref false; |
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(* Only for communication between unification and error message printing *) |
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val sgr = ref Sign.pre_pure |
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fun string_of_term env binders t = Sign.string_of_term (!sgr) |
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(Envir.norm_term env (subst_bounds(map Free binders,t))); |
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fun bname binders i = fst(nth_elem(i,binders)); |
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fun bnames binders is = space_implode " " (map (bname binders) is); |
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fun typ_clash(tye,T,U) = |
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if !trace_unify_fail |
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then let val t = Sign.string_of_typ (!sgr) (Envir.norm_type tye T) |
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and u = Sign.string_of_typ (!sgr) (Envir.norm_type tye U) |
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in tracing("The following types do not unify:\n" ^ t ^ "\n" ^ u) end |
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else () |
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fun clash a b = |
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if !trace_unify_fail then tracing("Clash: " ^ a ^ " =/= " ^ b) else () |
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fun boundVar binders i = |
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"bound variable " ^ bname binders i ^ " (depth " ^ string_of_int i ^ ")"; |
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fun clashBB binders i j = |
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if !trace_unify_fail then clash (boundVar binders i) (boundVar binders j) |
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else () |
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fun clashB binders i s = |
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if !trace_unify_fail then clash (boundVar binders i) s |
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else () |
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fun proj_fail(env,binders,F,is,t) = |
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if !trace_unify_fail |
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then let val f = Syntax.string_of_vname F |
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val xs = bnames binders is |
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val u = string_of_term env binders t |
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val ys = bnames binders (loose_bnos t \\ is) |
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in tracing("Cannot unify variable " ^ f ^ |
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" (depending on bound variables " ^ xs ^ ")\nwith term " ^ u ^ |
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"\nTerm contains additional bound variable(s) " ^ ys) |
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end |
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else () |
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fun ocheck_fail(F,t,binders,env) = |
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if !trace_unify_fail |
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then let val f = Syntax.string_of_vname F |
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val u = string_of_term env binders t |
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in tracing("Variable " ^ f ^ " occurs in term\n" ^ u ^ |
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"\nCannot unify!\n") |
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end |
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else () |
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fun occurs(F,t,env) = |
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let fun occ(Var(G,_)) = (case Envir.lookup(env,G) of |
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Some(t) => occ t |
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| None => F=G) |
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| occ(t1$t2) = occ t1 orelse occ t2 |
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| occ(Abs(_,_,t)) = occ t |
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| occ _ = false |
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in occ t end; |
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fun mapbnd f = |
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let fun mpb d (Bound(i)) = if i < d then Bound(i) else Bound(f(i-d)+d) |
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| mpb d (Abs(s,T,t)) = Abs(s,T,mpb(d+1) t) |
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| mpb d ((u1 $ u2)) = (mpb d u1)$(mpb d u2) |
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| mpb _ atom = atom |
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in mpb 0 end; |
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fun idx [] j = ~10000 |
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| idx(i::is) j = if i=j then length is else idx is j; |
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fun at xs i = nth_elem (i,xs); |
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fun mkabs (binders,is,t) = |
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let fun mk(i::is) = let val (x,T) = nth_elem(i,binders) |
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in Abs(x,T,mk is) end |
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| mk [] = t |
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in mk is end; |
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val incr = mapbnd (fn i => i+1); |
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fun ints_of [] = [] |
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| ints_of (Bound i ::bs) = |
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let val is = ints_of bs |
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in if i mem_int is then raise Pattern else i::is end |
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| ints_of _ = raise Pattern; |
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fun ints_of' env ts = ints_of (map (Envir.head_norm env) ts); |
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fun app (s,(i::is)) = app (s$Bound(i),is) |
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| app (s,[]) = s; |
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fun red (Abs(_,_,s)) (i::is) js = red s is (i::js) |
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| red t [] [] = t |
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| red t is jn = app (mapbnd (at jn) t,is); |
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(* split_type ([T1,....,Tn]---> T,n,[]) = ([Tn,...,T1],T) *) |
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fun split_type (T,0,Ts) = (Ts,T) |
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| split_type (Type ("fun",[T1,T2]),n,Ts) = split_type (T2,n-1,T1::Ts) |
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| split_type _ = error("split_type"); |
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fun type_of_G (T,n,is) = |
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let val (Ts,U) = split_type(T,n,[]) in map(at Ts)is ---> U end; |
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fun mkhnf (binders,is,G,js) = mkabs (binders, is, app(G,js)); |
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fun mknewhnf(env,binders,is,F as (a,_),T,js) = |
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let val (env',G) = Envir.genvar a (env,type_of_G(T,length is,js)) |
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in Envir.update((F,mkhnf(binders,is,G,js)),env') end; |
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(* mk_proj_list(is) = [ |is| - k | 1 <= k <= |is| and is[k] >= 0 ] *) |
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fun mk_proj_list is = |
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let fun mk(i::is,j) = if i >= 0 then j :: mk(is,j-1) else mk(is,j-1) |
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171 |
| mk([],_) = [] |
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in mk(is,length is - 1) end; |
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fun proj(s,env,binders,is) = |
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let fun trans d i = if i<d then i else (idx is (i-d))+d; |
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fun pr(s,env,d,binders) = (case Envir.head_norm env s of |
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Abs(a,T,t) => let val (t',env') = pr(t,env,d+1,((a,T)::binders)) |
178 |
in (Abs(a,T,t'),env') end |
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| t => (case strip_comb t of |
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(c as Const _,ts) => |
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let val (ts',env') = prs(ts,env,d,binders) |
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in (list_comb(c,ts'),env') end |
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| (f as Free _,ts) => |
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let val (ts',env') = prs(ts,env,d,binders) |
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in (list_comb(f,ts'),env') end |
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| (Bound(i),ts) => |
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let val j = trans d i |
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188 |
in if j < 0 then raise Unif |
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else let val (ts',env') = prs(ts,env,d,binders) |
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in (list_comb(Bound j,ts'),env') end |
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191 |
end |
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| (Var(F as (a,_),Fty),ts) => |
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let val js = ints_of' env ts; |
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val js' = map (trans d) js; |
195 |
val ks = mk_proj_list js'; |
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val ls = filter (fn i => i >= 0) js' |
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197 |
val Hty = type_of_G(Fty,length js,ks) |
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val (env',H) = Envir.genvar a (env,Hty) |
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val env'' = |
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200 |
Envir.update((F,mkhnf(binders,js,H,ks)),env') |
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in (app(H,ls),env'') end |
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| _ => raise Pattern)) |
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and prs(s::ss,env,d,binders) = |
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let val (s',env1) = pr(s,env,d,binders) |
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205 |
val (ss',env2) = prs(ss,env1,d,binders) |
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in (s'::ss',env2) end |
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| prs([],env,_,_) = ([],env) |
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in if downto0(is,length binders - 1) then (s,env) |
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else pr(s,env,0,binders) |
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210 |
end; |
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211 |
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212 |
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213 |
(* mk_ff_list(is,js) = [ length(is) - k | 1 <= k <= |is| and is[k] = js[k] ] *) |
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fun mk_ff_list(is,js) = |
215 |
let fun mk([],[],_) = [] |
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| mk(i::is,j::js, k) = if i=j then k :: mk(is,js,k-1) |
217 |
else mk(is,js,k-1) |
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| mk _ = error"mk_ff_list" |
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in mk(is,js,length is-1) end; |
220 |
||
221 |
fun flexflex1(env,binders,F,Fty,is,js) = |
|
222 |
if is=js then env |
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223 |
else let val ks = mk_ff_list(is,js) |
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in mknewhnf(env,binders,is,F,Fty,ks) end; |
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fun flexflex2(env,binders,F,Fty,is,G,Gty,js) = |
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let fun ff(F,Fty,is,G as (a,_),Gty,js) = |
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if js subset_int is |
0 | 229 |
then let val t= mkabs(binders,is,app(Var(G,Gty),map (idx is) js)) |
230 |
in Envir.update((F,t),env) end |
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else let val ks = is inter_int js |
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val Hty = type_of_G(Fty,length is,map (idx is) ks) |
233 |
val (env',H) = Envir.genvar a (env,Hty) |
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234 |
fun lam(is) = mkabs(binders,is,app(H,map (idx is) ks)); |
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235 |
in Envir.update((G,lam js), Envir.update((F,lam is),env')) |
|
236 |
end; |
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237 |
in if xless(G,F) then ff(F,Fty,is,G,Gty,js) else ff(G,Gty,js,F,Fty,is) end |
|
238 |
||
239 |
val tsgr = ref(Type.tsig0); |
|
240 |
||
241 |
fun unify_types(T,U, env as Envir.Envir{asol,iTs,maxidx}) = |
|
242 |
if T=U then env |
|
12527 | 243 |
else let val (iTs',maxidx') = Type.unify (!tsgr) (iTs, maxidx) (U, T) |
1435
aefcd255ed4a
Removed bug in type unification. Negative indexes are not used any longer.
nipkow
parents:
1029
diff
changeset
|
244 |
in Envir.Envir{asol=asol,maxidx=maxidx',iTs=iTs'} end |
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
245 |
handle Type.TUNIFY => (typ_clash(iTs,T,U); raise Unif); |
0 | 246 |
|
12232 | 247 |
fun unif binders (env,(s,t)) = case (Envir.head_norm env s, Envir.head_norm env t) of |
0 | 248 |
(Abs(ns,Ts,ts),Abs(nt,Tt,tt)) => |
249 |
let val name = if ns = "" then nt else ns |
|
250 |
in unif ((name,Ts)::binders) (env,(ts,tt)) end |
|
251 |
| (Abs(ns,Ts,ts),t) => unif ((ns,Ts)::binders) (env,(ts,(incr t)$Bound(0))) |
|
252 |
| (t,Abs(nt,Tt,tt)) => unif ((nt,Tt)::binders) (env,((incr t)$Bound(0),tt)) |
|
253 |
| p => cases(binders,env,p) |
|
254 |
||
255 |
and cases(binders,env,(s,t)) = case (strip_comb s,strip_comb t) of |
|
12784 | 256 |
((Var(F,Fty),ss),(Var(G,Gty),ts)) => |
12232 | 257 |
if F = G then flexflex1(env,binders,F,Fty,ints_of' env ss,ints_of' env ts) |
258 |
else flexflex2(env,binders,F,Fty,ints_of' env ss,G,Gty,ints_of' env ts) |
|
259 |
| ((Var(F,_),ss),_) => flexrigid(env,binders,F,ints_of' env ss,t) |
|
260 |
| (_,(Var(F,_),ts)) => flexrigid(env,binders,F,ints_of' env ts,s) |
|
0 | 261 |
| ((Const c,ss),(Const d,ts)) => rigidrigid(env,binders,c,d,ss,ts) |
262 |
| ((Free(f),ss),(Free(g),ts)) => rigidrigid(env,binders,f,g,ss,ts) |
|
12784 | 263 |
| ((Bound(i),ss),(Bound(j),ts)) => rigidrigidB (env,binders,i,j,ss,ts) |
0 | 264 |
| ((Abs(_),_),_) => raise Pattern |
265 |
| (_,(Abs(_),_)) => raise Pattern |
|
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
266 |
| ((Const(c,_),_),(Free(f,_),_)) => (clash c f; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
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parents:
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diff
changeset
|
267 |
| ((Const(c,_),_),(Bound i,_)) => (clashB binders i c; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
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diff
changeset
|
268 |
| ((Free(f,_),_),(Const(c,_),_)) => (clash f c; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
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diff
changeset
|
269 |
| ((Free(f,_),_),(Bound i,_)) => (clashB binders i f; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
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diff
changeset
|
270 |
| ((Bound i,_),(Const(c,_),_)) => (clashB binders i c; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
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parents:
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diff
changeset
|
271 |
| ((Bound i,_),(Free(f,_),_)) => (clashB binders i f; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
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parents:
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diff
changeset
|
272 |
|
0 | 273 |
|
274 |
and rigidrigid (env,binders,(a,Ta),(b,Tb),ss,ts) = |
|
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
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diff
changeset
|
275 |
if a<>b then (clash a b; raise Unif) |
0 | 276 |
else foldl (unif binders) (unify_types(Ta,Tb,env), ss~~ts) |
277 |
||
278 |
and rigidrigidB (env,binders,i,j,ss,ts) = |
|
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
279 |
if i <> j then (clashBB binders i j; raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
280 |
else foldl (unif binders) (env ,ss~~ts) |
0 | 281 |
|
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
282 |
and flexrigid (params as (env,binders,F,is,t)) = |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
283 |
if occurs(F,t,env) then (ocheck_fail(F,t,binders,env); raise Unif) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
284 |
else (let val (u,env') = proj(t,env,binders,is) |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
285 |
in Envir.update((F,mkabs(binders,is,u)),env') end |
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
286 |
handle Unif => (proj_fail params; raise Unif)); |
0 | 287 |
|
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
288 |
fun unify(sg,env,tus) = (sgr := sg; tsgr := #tsig(Sign.rep_sg sg); |
0 | 289 |
foldl (unif []) (env,tus)); |
290 |
||
291 |
||
2725
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
292 |
(*Eta-contract a term (fully)*) |
2792 | 293 |
|
12797 | 294 |
fun eta_contract t = |
295 |
let |
|
296 |
exception SAME; |
|
297 |
fun eta (Abs (a, T, body)) = |
|
298 |
((case eta body of |
|
299 |
body' as (f $ Bound 0) => |
|
300 |
if loose_bvar1 (f, 0) then Abs(a, T, body') |
|
301 |
else incr_boundvars ~1 f |
|
302 |
| body' => Abs (a, T, body')) handle SAME => |
|
303 |
(case body of |
|
304 |
(f $ Bound 0) => |
|
305 |
if loose_bvar1 (f, 0) then raise SAME |
|
306 |
else incr_boundvars ~1 f |
|
307 |
| _ => raise SAME)) |
|
308 |
| eta (f $ t) = |
|
309 |
(let val f' = eta f |
|
310 |
in f' $ etah t end handle SAME => f $ eta t) |
|
311 |
| eta _ = raise SAME |
|
312 |
and etah t = (eta t handle SAME => t) |
|
313 |
in etah t end; |
|
0 | 314 |
|
12781 | 315 |
val beta_eta_contract = eta_contract o Envir.beta_norm; |
316 |
||
6539
2e7d2fba9f6c
Eta contraction is now performed all the time during rewriting.
nipkow
parents:
4820
diff
changeset
|
317 |
(*Eta-contract a term from outside: just enough to reduce it to an atom |
2e7d2fba9f6c
Eta contraction is now performed all the time during rewriting.
nipkow
parents:
4820
diff
changeset
|
318 |
DOESN'T QUITE WORK! |
2e7d2fba9f6c
Eta contraction is now performed all the time during rewriting.
nipkow
parents:
4820
diff
changeset
|
319 |
*) |
12784 | 320 |
fun eta_contract_atom (t0 as Abs(a, T, body)) = |
2725
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
321 |
(case eta_contract2 body of |
12784 | 322 |
body' as (f $ Bound 0) => |
323 |
if loose_bvar1(f,0) then Abs(a,T,body') |
|
324 |
else eta_contract_atom (incr_boundvars ~1 f) |
|
2725
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
325 |
| _ => t0) |
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
326 |
| eta_contract_atom t = t |
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
327 |
and eta_contract2 (f$t) = f $ eta_contract_atom t |
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
328 |
| eta_contract2 t = eta_contract_atom t; |
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
329 |
|
9453616d4b80
Declares eta_contract_atom; fixed comment; some tidying
paulson
parents:
2616
diff
changeset
|
330 |
|
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
331 |
(*Tests whether 2 terms are alpha/eta-convertible and have same type. |
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
332 |
Note that Consts and Vars may have more than one type.*) |
2751 | 333 |
fun t aeconv u = aconv_aux (eta_contract_atom t, eta_contract_atom u) |
334 |
and aconv_aux (Const(a,T), Const(b,U)) = a=b andalso T=U |
|
335 |
| aconv_aux (Free(a,T), Free(b,U)) = a=b andalso T=U |
|
336 |
| aconv_aux (Var(v,T), Var(w,U)) = eq_ix(v,w) andalso T=U |
|
12784 | 337 |
| aconv_aux (Bound i, Bound j) = i=j |
2751 | 338 |
| aconv_aux (Abs(_,T,t), Abs(_,U,u)) = (t aeconv u) andalso T=U |
12784 | 339 |
| aconv_aux (f$t, g$u) = (f aeconv g) andalso (t aeconv u) |
2751 | 340 |
| aconv_aux _ = false; |
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
341 |
|
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
342 |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
343 |
(*** Matching ***) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
344 |
|
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
345 |
exception MATCH; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
346 |
|
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
347 |
fun typ_match tsig args = (Type.typ_match tsig args) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
348 |
handle Type.TYPE_MATCH => raise MATCH; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
349 |
|
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
350 |
(*First-order matching; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
351 |
fomatch tsig (pattern, object) returns a (tyvar,typ)list and (var,term)list. |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
352 |
The pattern and object may have variables in common. |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
353 |
Instantiation does not affect the object, so matching ?a with ?a+1 works. |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
354 |
Object is eta-contracted on the fly (by eta-expanding the pattern). |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
355 |
Precondition: the pattern is already eta-contracted! |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
356 |
Note: types are matched on the fly *) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
357 |
fun fomatch tsig = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
358 |
let |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
359 |
fun mtch (instsp as (tyinsts,insts)) = fn |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
360 |
(Var(ixn,T), t) => |
12784 | 361 |
if loose_bvar(t,0) then raise MATCH |
362 |
else (case assoc_string_int(insts,ixn) of |
|
363 |
None => (typ_match tsig (tyinsts, (T, fastype_of t)), |
|
364 |
(ixn,t)::insts) |
|
365 |
| Some u => if t aeconv u then instsp else raise MATCH) |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
366 |
| (Free (a,T), Free (b,U)) => |
12784 | 367 |
if a=b then (typ_match tsig (tyinsts,(T,U)), insts) else raise MATCH |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
368 |
| (Const (a,T), Const (b,U)) => |
12784 | 369 |
if a=b then (typ_match tsig (tyinsts,(T,U)), insts) else raise MATCH |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
370 |
| (Bound i, Bound j) => if i=j then instsp else raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
371 |
| (Abs(_,T,t), Abs(_,U,u)) => |
12784 | 372 |
mtch (typ_match tsig (tyinsts,(T,U)),insts) (t,u) |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
373 |
| (f$t, g$u) => mtch (mtch instsp (f,g)) (t, u) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
374 |
| (t, Abs(_,U,u)) => mtch instsp ((incr t)$(Bound 0), u) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
375 |
| _ => raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
376 |
in mtch end; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
377 |
|
8406
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
378 |
fun first_order_match tsig = apfst Vartab.dest o fomatch tsig (Vartab.empty, []); |
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
379 |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
380 |
(* Matching of higher-order patterns *) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
381 |
|
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
382 |
fun match_bind(itms,binders,ixn,is,t) = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
383 |
let val js = loose_bnos t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
384 |
in if null is |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
385 |
then if null js then (ixn,t)::itms else raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
386 |
else if js subset_int is |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
387 |
then let val t' = if downto0(is,length binders - 1) then t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
388 |
else mapbnd (idx is) t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
389 |
in (ixn, mkabs(binders,is,t')) :: itms end |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
390 |
else raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
391 |
end; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
392 |
|
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
393 |
fun match tsg (po as (pat,obj)) = |
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
394 |
let |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
395 |
(* Pre: pat and obj have same type *) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
396 |
fun mtch binders (env as (iTs,itms),(pat,obj)) = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
397 |
case pat of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
398 |
Abs(ns,Ts,ts) => |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
399 |
(case obj of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
400 |
Abs(nt,Tt,tt) => mtch ((nt,Tt)::binders) (env,(ts,tt)) |
8406
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
401 |
| _ => let val Tt = typ_subst_TVars_Vartab iTs Ts |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
402 |
in mtch((ns,Tt)::binders)(env,(ts,(incr obj)$Bound(0))) end) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
403 |
| _ => (case obj of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
404 |
Abs(nt,Tt,tt) => |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
405 |
mtch((nt,Tt)::binders)(env,((incr pat)$Bound(0),tt)) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
406 |
| _ => cases(binders,env,pat,obj)) |
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
407 |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
408 |
and cases(binders,env as (iTs,itms),pat,obj) = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
409 |
let val (ph,pargs) = strip_comb pat |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
410 |
fun rigrig1(iTs,oargs) = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
411 |
foldl (mtch binders) ((iTs,itms), pargs~~oargs) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
412 |
fun rigrig2((a,Ta),(b,Tb),oargs) = |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
413 |
if a<> b then raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
414 |
else rigrig1(typ_match tsg (iTs,(Ta,Tb)), oargs) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
415 |
in case ph of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
416 |
Var(ixn,_) => |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
417 |
let val is = ints_of pargs |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
418 |
in case assoc_string_int(itms,ixn) of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
419 |
None => (iTs,match_bind(itms,binders,ixn,is,obj)) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
420 |
| Some u => if obj aeconv (red u is []) then env |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
421 |
else raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
422 |
end |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
423 |
| _ => |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
424 |
let val (oh,oargs) = strip_comb obj |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
425 |
in case (ph,oh) of |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
426 |
(Const c,Const d) => rigrig2(c,d,oargs) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
427 |
| (Free f,Free g) => rigrig2(f,g,oargs) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
428 |
| (Bound i,Bound j) => if i<>j then raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
429 |
else rigrig1(iTs,oargs) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
430 |
| (Abs _, _) => raise Pattern |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
431 |
| (_, Abs _) => raise Pattern |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
432 |
| _ => raise MATCH |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
433 |
end |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
434 |
end; |
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
435 |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
436 |
val pT = fastype_of pat |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
437 |
and oT = fastype_of obj |
8406
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
438 |
val iTs = typ_match tsg (Vartab.empty, (pT,oT)) |
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
439 |
val insts2 = (iTs,[]) |
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
440 |
|
8406
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
441 |
in apfst Vartab.dest (mtch [] (insts2, po) |
a217b0cd304d
Type.unify and Type.typ_match now use Vartab instead of association lists.
berghofe
parents:
6539
diff
changeset
|
442 |
handle Pattern => fomatch tsg insts2 po) |
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
443 |
end; |
0 | 444 |
|
445 |
(*Predicate: does the pattern match the object?*) |
|
678
6151b7f3b606
Modified pattern.ML to perform proper matching of Higher-Order Patterns.
nipkow
parents:
63
diff
changeset
|
446 |
fun matches tsig po = (match tsig po; true) handle MATCH => false; |
0 | 447 |
|
4667
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
448 |
(* Does pat match a subterm of obj? *) |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
449 |
fun matches_subterm tsig (pat,obj) = |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
450 |
let fun msub(bounds,obj) = matches tsig (pat,obj) orelse |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
451 |
case obj of |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
452 |
Abs(x,T,t) => let val y = variant bounds x |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
453 |
val f = Free(":" ^ y,T) |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
454 |
in msub(x::bounds,subst_bound(f,t)) end |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
455 |
| s$t => msub(bounds,s) orelse msub(bounds,t) |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
456 |
| _ => false |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
457 |
in msub([],obj) end; |
6328d427a339
Tried to reorganize rewriter a little. More to be done.
nipkow
parents:
2792
diff
changeset
|
458 |
|
4820
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
459 |
fun first_order(Abs(_,_,t)) = first_order t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
460 |
| first_order(t $ u) = first_order t andalso first_order u andalso |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
461 |
not(is_Var t) |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
462 |
| first_order _ = true; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
463 |
|
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
464 |
fun pattern(Abs(_,_,t)) = pattern t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
465 |
| pattern(t) = let val (head,args) = strip_comb t |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
466 |
in if is_Var head |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
467 |
then let val _ = ints_of args in true end |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
468 |
handle Pattern => false |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
469 |
else forall pattern args |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
470 |
end; |
8f6dbbd8d497
Tried to speed up the rewriter by eta-contracting all patterns beforehand and
nipkow
parents:
4667
diff
changeset
|
471 |
|
12784 | 472 |
|
473 |
(* rewriting -- simple but fast *) |
|
474 |
||
13195 | 475 |
fun rewrite_term tsig rules procs tm = |
12784 | 476 |
let |
13195 | 477 |
val skel0 = Bound 0; |
478 |
||
12797 | 479 |
val rhs_names = |
480 |
foldr (fn ((_, rhs), names) => add_term_free_names (rhs, names)) (rules, []); |
|
13195 | 481 |
|
12797 | 482 |
fun variant_absfree (x, T, t) = |
483 |
let |
|
484 |
val x' = variant (add_term_free_names (t, rhs_names)) x; |
|
485 |
val t' = subst_bound (Free (x', T), t); |
|
486 |
in (fn u => Abs (x, T, abstract_over (Free (x', T), u)), t') end; |
|
487 |
||
12784 | 488 |
fun match_rew tm (tm1, tm2) = |
13195 | 489 |
let val rtm = if_none (Term.rename_abs tm1 tm tm2) tm2 |
490 |
in Some (subst_vars (match tsig (tm1, tm)) rtm, rtm) |
|
491 |
handle MATCH => None |
|
492 |
end; |
|
12784 | 493 |
|
13195 | 494 |
fun rew (Abs (_, _, body) $ t) = Some (subst_bound (t, body), skel0) |
495 |
| rew tm = (case get_first (match_rew tm) rules of |
|
496 |
None => apsome (rpair skel0) (get_first (fn p => p tm) procs) |
|
497 |
| x => x); |
|
498 |
||
499 |
fun rew1 (Var _) _ = None |
|
500 |
| rew1 skel tm = (case rew2 skel tm of |
|
12817
fcbb6ad5c790
rewrite_term: removed rew0, so no on-the-fly eta-contraction;
wenzelm
parents:
12797
diff
changeset
|
501 |
Some tm1 => (case rew tm1 of |
13195 | 502 |
Some (tm2, skel') => Some (if_none (rew1 skel' tm2) tm2) |
12784 | 503 |
| None => Some tm1) |
12817
fcbb6ad5c790
rewrite_term: removed rew0, so no on-the-fly eta-contraction;
wenzelm
parents:
12797
diff
changeset
|
504 |
| None => (case rew tm of |
13195 | 505 |
Some (tm1, skel') => Some (if_none (rew1 skel' tm1) tm1) |
12784 | 506 |
| None => None)) |
507 |
||
13195 | 508 |
and rew2 skel (tm1 $ tm2) = (case tm1 of |
12784 | 509 |
Abs (_, _, body) => |
510 |
let val tm' = subst_bound (tm2, body) |
|
13195 | 511 |
in Some (if_none (rew2 skel0 tm') tm') end |
512 |
| _ => |
|
513 |
let val (skel1, skel2) = (case skel of |
|
514 |
skel1 $ skel2 => (skel1, skel2) |
|
515 |
| _ => (skel0, skel0)) |
|
516 |
in case rew1 skel1 tm1 of |
|
517 |
Some tm1' => (case rew1 skel2 tm2 of |
|
518 |
Some tm2' => Some (tm1' $ tm2') |
|
519 |
| None => Some (tm1' $ tm2)) |
|
520 |
| None => (case rew1 skel2 tm2 of |
|
521 |
Some tm2' => Some (tm1 $ tm2') |
|
522 |
| None => None) |
|
523 |
end) |
|
524 |
| rew2 skel (Abs (x, T, tm)) = |
|
525 |
let |
|
526 |
val (abs, tm') = variant_absfree (x, T, tm); |
|
527 |
val skel' = (case skel of Abs (_, _, skel') => skel' | _ => skel0) |
|
528 |
in case rew1 skel' tm' of |
|
12797 | 529 |
Some tm'' => Some (abs tm'') |
13195 | 530 |
| None => None |
12797 | 531 |
end |
13195 | 532 |
| rew2 _ _ = None |
12784 | 533 |
|
13195 | 534 |
in if_none (rew1 skel0 tm) tm end; |
12784 | 535 |
|
0 | 536 |
end; |
13642
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
537 |
|
a3d97348ceb6
added failure trace information to pattern unification
nipkow
parents:
13195
diff
changeset
|
538 |
val trace_unify_fail = Pattern.trace_unify_fail; |