* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-*)
+ *)
(* Evaluation of expressions until only externs are around *)
open Ast Print Env
+structure SM = StringMap
+
fun freeIn x (b, _) =
case b of
EInt _ => false
| ESkip => false
| ESet (_, e) => freeIn x e
- | EGet (x', _, b') => x <> x' andalso freeIn x b'
+ | EGet (x', _, _, b') => x <> x' andalso freeIn x b'
| ESeq es => List.exists (freeIn x) es
| ELocal (e1, e2) => freeIn x e1 orelse freeIn x e2
| EWith (e1, e2) => freeIn x e1 orelse freeIn x e2
+ | EALam (x', _, b') => x <> x' andalso freeIn x b'
+
+ | EIf (e1, e2, e3) => freeIn x e1 orelse freeIn x e2 orelse freeIn x e3
local
val freshCount = ref 0
| ESkip => bAll
| ESet (v, b) => (ESet (v, subst x e b), loc)
- | EGet (x', v, b') =>
+ | EGet (x', topt, v, b') =>
if x = x' then
bAll
else if freeIn x' e then
let
val x'' = freshVar ()
in
- (EGet (x'', v, subst x e (subst x' (EVar x'', loc) b')), loc)
+ (EGet (x'', topt, v, subst x e (subst x' (EVar x'', loc) b')), loc)
end
else
- (EGet (x', v, subst x e b'), loc)
+ (EGet (x', topt, v, subst x e b'), loc)
| ESeq es => (ESeq (map (subst x e) es), loc)
| ELocal (b1, b2) => (ELocal (subst x e b1, subst x e b2), loc)
| EWith (b1, b2) => (EWith (subst x e b1, subst x e b2), loc)
+ | EALam (x', p, b') =>
+ if x = x' then
+ bAll
+ else if freeIn x' e then
+ let
+ val x'' = freshVar ()
+ in
+ (EALam (x'', p, subst x e (subst x' (EVar x'', loc) b')), loc)
+ end
+ else
+ (EALam (x', p, subst x e b'), loc)
+
+ | EIf (b1, b2, b3) => (EIf (subst x e b1, subst x e b2, subst x e b3), loc)
+
+fun findPrim (e, _) =
+ case e of
+ EApp (f, x) =>
+ (case findPrim f of
+ NONE => NONE
+ | SOME (f, xs) => SOME (f, xs @ [x]))
+ | EVar x => SOME (x, [])
+ | _ => NONE
fun reduceExp G (eAll as (e, loc)) =
case e of
end
| EVar x =>
(case lookupEquation G x of
- NONE => eAll
+ NONE =>
+ (case function x of
+ NONE => eAll
+ | SOME f => case f [] of
+ NONE => eAll
+ | SOME e' => reduceExp G e')
| SOME e => reduceExp G e)
| EApp (e1, e2) =>
let
in
case e1' of
(ELam (x, _, b), _) => reduceExp G (subst x e2' b)
- | _ => (EApp (e1', e2'), loc)
+ | _ =>
+ case findPrim eAll of
+ NONE => (EApp (e1', e2'), loc)
+ | SOME (f, args) =>
+ case function f of
+ NONE => (EApp (e1', e2'), loc)
+ | SOME f => case f (map (reduceExp G) args) of
+ NONE => (EApp (e1', e2'), loc)
+ | SOME e' => reduceExp G e'
end
| ESkip => eAll
| ESet (v, b) => (ESet (v, reduceExp G b), loc)
- | EGet (x, v, b) => (EGet (x, v, reduceExp G b), loc)
+ | EGet (x, topt, v, b) => (EGet (x, topt, v, reduceExp G b), loc)
| ESeq es => (ESeq (map (reduceExp G) es), loc)
| ELocal (e1, e2) => (ELocal (reduceExp G e1, reduceExp G e2), loc)
- | EWith (e1, e2) => (EWith (reduceExp G e1, reduceExp G e2), loc)
+ | EWith (e1, e2) =>
+ let
+ val e1' = reduceExp G e1
+ val e2' = reduceExp G e2
+ in
+ case e1' of
+ (EALam (x, _, b), _) => reduceExp G (subst x e2' b)
+ | _ => (EWith (e1', e2'), loc)
+ end
+ | EALam (x, p, e) =>
+ let
+ val G' = bindVal G (x, (TAction (p, SM.empty, SM.empty), loc), NONE)
+ in
+ (EALam (x, p, reduceExp G' e), loc)
+ end
+
+ | EIf (e1, e2, e3) =>
+ let
+ val e1' = reduceExp G e1
+ fun e2' () = reduceExp G e2
+ fun e3' () = reduceExp G e3
+ in
+ case e1' of
+ (EVar "true", _) => e2' ()
+ | (EVar "false", _) => e3' ()
+ | _ => (EIf (e1', e2' (), e3' ()), loc)
+ end
end