--- a/src/HOL/Matrix/Compute_Oracle/am_interpreter.ML Sat Mar 17 12:26:19 2012 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,211 +0,0 @@
-(* Title: HOL/Matrix/Compute_Oracle/am_interpreter.ML
- Author: Steven Obua
-*)
-
-signature AM_BARRAS =
-sig
- include ABSTRACT_MACHINE
- val max_reductions : int option Unsynchronized.ref
-end
-
-structure AM_Interpreter : AM_BARRAS = struct
-
-open AbstractMachine;
-
-datatype closure = CDummy | CVar of int | CConst of int
- | CApp of closure * closure | CAbs of closure
- | Closure of (closure list) * closure
-
-structure prog_struct = Table(type key = int*int val ord = prod_ord int_ord int_ord);
-
-datatype program = Program of ((pattern * closure * (closure*closure) list) list) prog_struct.table
-
-datatype stack = SEmpty | SAppL of closure * stack | SAppR of closure * stack | SAbs of stack
-
-fun clos_of_term (Var x) = CVar x
- | clos_of_term (Const c) = CConst c
- | clos_of_term (App (u, v)) = CApp (clos_of_term u, clos_of_term v)
- | clos_of_term (Abs u) = CAbs (clos_of_term u)
- | clos_of_term (Computed t) = clos_of_term t
-
-fun term_of_clos (CVar x) = Var x
- | term_of_clos (CConst c) = Const c
- | term_of_clos (CApp (u, v)) = App (term_of_clos u, term_of_clos v)
- | term_of_clos (CAbs u) = Abs (term_of_clos u)
- | term_of_clos (Closure _) = raise (Run "internal error: closure in normalized term found")
- | term_of_clos CDummy = raise (Run "internal error: dummy in normalized term found")
-
-fun resolve_closure closures (CVar x) = (case nth closures x of CDummy => CVar x | r => r)
- | resolve_closure closures (CConst c) = CConst c
- | resolve_closure closures (CApp (u, v)) = CApp (resolve_closure closures u, resolve_closure closures v)
- | resolve_closure closures (CAbs u) = CAbs (resolve_closure (CDummy::closures) u)
- | resolve_closure closures (CDummy) = raise (Run "internal error: resolve_closure applied to CDummy")
- | resolve_closure closures (Closure (e, u)) = resolve_closure e u
-
-fun resolve_closure' c = resolve_closure [] c
-
-fun resolve_stack tm SEmpty = tm
- | resolve_stack tm (SAppL (c, s)) = resolve_stack (CApp (tm, resolve_closure' c)) s
- | resolve_stack tm (SAppR (c, s)) = resolve_stack (CApp (resolve_closure' c, tm)) s
- | resolve_stack tm (SAbs s) = resolve_stack (CAbs tm) s
-
-fun resolve (stack, closure) =
- let
- val _ = writeln "start resolving"
- val t = resolve_stack (resolve_closure' closure) stack
- val _ = writeln "finished resolving"
- in
- t
- end
-
-fun strip_closure args (CApp (a,b)) = strip_closure (b::args) a
- | strip_closure args x = (x, args)
-
-fun len_head_of_closure n (CApp (a, _)) = len_head_of_closure (n+1) a
- | len_head_of_closure n x = (n, x)
-
-
-(* earlier occurrence of PVar corresponds to higher de Bruijn index *)
-fun pattern_match args PVar clos = SOME (clos::args)
- | pattern_match args (PConst (c, patterns)) clos =
- let
- val (f, closargs) = strip_closure [] clos
- in
- case f of
- CConst d =>
- if c = d then
- pattern_match_list args patterns closargs
- else
- NONE
- | _ => NONE
- end
-and pattern_match_list args [] [] = SOME args
- | pattern_match_list args (p::ps) (c::cs) =
- (case pattern_match args p c of
- NONE => NONE
- | SOME args => pattern_match_list args ps cs)
- | pattern_match_list _ _ _ = NONE
-
-fun count_patternvars PVar = 1
- | count_patternvars (PConst (_, ps)) = List.foldl (fn (p, count) => (count_patternvars p)+count) 0 ps
-
-fun pattern_key (PConst (c, ps)) = (c, length ps)
- | pattern_key _ = raise (Compile "pattern reduces to variable")
-
-(*Returns true iff at most 0 .. (free-1) occur unbound. therefore
- check_freevars 0 t iff t is closed*)
-fun check_freevars free (Var x) = x < free
- | check_freevars free (Const _) = true
- | check_freevars free (App (u, v)) = check_freevars free u andalso check_freevars free v
- | check_freevars free (Abs m) = check_freevars (free+1) m
- | check_freevars free (Computed t) = check_freevars free t
-
-fun compile eqs =
- let
- fun check p r = if check_freevars p r then () else raise Compile ("unbound variables in rule")
- fun check_guard p (Guard (a,b)) = (check p a; check p b)
- fun clos_of_guard (Guard (a,b)) = (clos_of_term a, clos_of_term b)
- val eqs = map (fn (guards, p, r) => let val pcount = count_patternvars p val _ = map (check_guard pcount) (guards) val _ = check pcount r in
- (pattern_key p, (p, clos_of_term r, map clos_of_guard guards)) end) eqs
- fun merge (k, a) table = prog_struct.update (k, case prog_struct.lookup table k of NONE => [a] | SOME l => a::l) table
- val p = fold merge eqs prog_struct.empty
- in
- Program p
- end
-
-
-type state = bool * program * stack * closure
-
-datatype loopstate = Continue of state | Stop of stack * closure
-
-fun proj_C (Continue s) = s
- | proj_C _ = raise Match
-
-exception InterruptedExecution of stack * closure
-
-fun proj_S (Stop s) = s
- | proj_S (Continue (_,_,s,c)) = (s,c)
-
-fun cont (Continue _) = true
- | cont _ = false
-
-val max_reductions = Unsynchronized.ref (NONE : int option)
-
-fun do_reduction reduce p =
- let
- val s = Unsynchronized.ref (Continue p)
- val counter = Unsynchronized.ref 0
- val _ = case !max_reductions of
- NONE => while cont (!s) do (s := reduce (proj_C (!s)))
- | SOME m => while cont (!s) andalso (!counter < m) do (s := reduce (proj_C (!s)); counter := (!counter) + 1)
- in
- case !max_reductions of
- SOME m => if !counter >= m then raise InterruptedExecution (proj_S (!s)) else proj_S (!s)
- | NONE => proj_S (!s)
- end
-
-fun match_rules prog n [] clos = NONE
- | match_rules prog n ((p,eq,guards)::rs) clos =
- case pattern_match [] p clos of
- NONE => match_rules prog (n+1) rs clos
- | SOME args => if forall (guard_checks prog args) guards then SOME (Closure (args, eq)) else match_rules prog (n+1) rs clos
-and guard_checks prog args (a,b) = (simp prog (Closure (args, a)) = simp prog (Closure (args, b)))
-and match_closure (p as (Program prog)) clos =
- case len_head_of_closure 0 clos of
- (len, CConst c) =>
- (case prog_struct.lookup prog (c, len) of
- NONE => NONE
- | SOME rules => match_rules p 0 rules clos)
- | _ => NONE
-
-and weak_reduce (false, prog, stack, Closure (e, CApp (a, b))) = Continue (false, prog, SAppL (Closure (e, b), stack), Closure (e, a))
- | weak_reduce (false, prog, SAppL (b, stack), Closure (e, CAbs m)) = Continue (false, prog, stack, Closure (b::e, m))
- | weak_reduce (false, prog, stack, Closure (e, CVar n)) = Continue (false, prog, stack, case nth e n of CDummy => CVar n | r => r)
- | weak_reduce (false, prog, stack, Closure (_, c as CConst _)) = Continue (false, prog, stack, c)
- | weak_reduce (false, prog, stack, clos) =
- (case match_closure prog clos of
- NONE => Continue (true, prog, stack, clos)
- | SOME r => Continue (false, prog, stack, r))
- | weak_reduce (true, prog, SAppR (a, stack), b) = Continue (false, prog, stack, CApp (a,b))
- | weak_reduce (true, prog, SAppL (b, stack), a) = Continue (false, prog, SAppR (a, stack), b)
- | weak_reduce (true, prog, stack, c) = Stop (stack, c)
-
-and strong_reduce (false, prog, stack, Closure (e, CAbs m)) =
- (let
- val (stack', wnf) = do_reduction weak_reduce (false, prog, SEmpty, Closure (CDummy::e, m))
- in
- case stack' of
- SEmpty => Continue (false, prog, SAbs stack, wnf)
- | _ => raise (Run "internal error in strong: weak failed")
- end handle InterruptedExecution state => raise InterruptedExecution (stack, resolve state))
- | strong_reduce (false, prog, stack, CApp (u, v)) = Continue (false, prog, SAppL (v, stack), u)
- | strong_reduce (false, prog, stack, clos) = Continue (true, prog, stack, clos)
- | strong_reduce (true, prog, SAbs stack, m) = Continue (false, prog, stack, CAbs m)
- | strong_reduce (true, prog, SAppL (b, stack), a) = Continue (false, prog, SAppR (a, stack), b)
- | strong_reduce (true, prog, SAppR (a, stack), b) = Continue (true, prog, stack, CApp (a, b))
- | strong_reduce (true, prog, stack, clos) = Stop (stack, clos)
-
-and simp prog t =
- (let
- val (stack, wnf) = do_reduction weak_reduce (false, prog, SEmpty, t)
- in
- case stack of
- SEmpty => (case do_reduction strong_reduce (false, prog, SEmpty, wnf) of
- (SEmpty, snf) => snf
- | _ => raise (Run "internal error in run: strong failed"))
- | _ => raise (Run "internal error in run: weak failed")
- end handle InterruptedExecution state => resolve state)
-
-
-fun run prog t =
- (let
- val (stack, wnf) = do_reduction weak_reduce (false, prog, SEmpty, Closure ([], clos_of_term t))
- in
- case stack of
- SEmpty => (case do_reduction strong_reduce (false, prog, SEmpty, wnf) of
- (SEmpty, snf) => term_of_clos snf
- | _ => raise (Run "internal error in run: strong failed"))
- | _ => raise (Run "internal error in run: weak failed")
- end handle InterruptedExecution state => term_of_clos (resolve state))
-
-end