Simplify semantics of private fields; add self syntax for classes

samples/bank.as

@@ -13,7 +13,7 @@ actor class Issuer() {
   };
 };
 
-actor class Account(initialBalance : Int) {
+actor class Account(initialBalance : Int) = this {
   private var balance : Int = initialBalance;
 
   getBalance() : async Int {
@@ -25,15 +25,15 @@ actor class Account(initialBalance : Int) {
     return Account(amount);
   };
 
-  join(account : Account) {  // this implicitly asserts that account is Account
+  join(account : like Account) {
+    assert(account is Account);
     let amount = balance;
     balance := 0;
-    account.credit(amount);
+    account.credit(amount, Account);
   };
 
-  private credit(amount : Int) {
-    // private implicitly asserts that caller is own class
-    // by implicitly passing the modref as an extra argument
+  credit(amount : Int, caller : Class) {
+    assert(this is caller);
     balance += amount;
   };
 

samples/bank.txt

@@ -1,5 +1,5 @@
 -- Checking bank.as:
-type Account <: actor {getBalance : shared () -> async Int; isCompatible : shared (like Account) -> async Bool; join : shared Account -> (); split : shared Int -> async Account}
+type Account <: actor {credit : shared (Int, Class) -> (); getBalance : shared () -> async Int; isCompatible : shared (like Account) -> async Bool; join : shared (like Account) -> (); split : shared Int -> async Account}
 type Bank <: actor {getIssuer : shared () -> async Issuer; getReserve : shared () -> async Account}
 type Issuer <: actor {hasIssued : shared (like Account) -> async Bool}
 let Account : class Int -> Account
@@ -15,8 +15,8 @@ Bank(100)
   Issuer()
     <= {hasIssued = func}
   Account(100)
-    <= {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}}
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {getIssuer = func; getReserve = func}
 test()
   -> async bank.as:56.40-68.2
   <= async _
@@ -28,8 +28,8 @@ test()
     -> async bank.as:7.32-7.51
     <= async _
 <- async bank.as:7.32-7.51
-  <= {balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:57.17-57.40({balance = 100; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:57.17-57.40({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await bank.as:58.12-58.35
 <- message split(10)
@@ -38,9 +38,9 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(10)
-    <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:58.12-58.35({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:58.12-58.35({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await bank.as:59.12-59.35
 <- message split(10)
@@ -49,16 +49,16 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(10)
-    <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:59.12-59.35({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  show("reserve", {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:59.12-59.35({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  transfer({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, 5)
+  transfer({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func}, 5)
     -> async bank.as:46.79-49.2
     <= async _
   => await bank.as:63.3-63.28
@@ -71,30 +71,32 @@ test()
     <= async _
 <- async bank.as:23.39-26.4
   Account(5)
-    <= {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-  <= {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}
-<- await bank.as:47.13-47.39({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  -> message join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; getBalance = func; isCompatible = func; join = func; split = func}
+<- await bank.as:47.13-47.39({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  -> message join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
   <= ()
-<- message join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-  join({balance = 10; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
-    credit(5)
-      <= ()
+<- message join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  join({credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+    -> message credit(5, class)
+    <= ()
+<- message credit(5, class)
+  credit(5, class)
     <= ()
 <- await bank.as:63.3-63.28()
-  show("reserve", {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
     <= ()
-  <= ({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+  <= ({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
 -- Finished bank.as:
 let Account : class Int -> Account = class
 let Bank : class Int -> Bank = class
 let Issuer : class () -> Issuer = class
-let bank : Bank = {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 80; credit = func; getBalance = func; isCompatible = func; join = func; split = func}}
-let main : async (Account, Account) = async ({balance = 5; credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; getBalance = func; isCompatible = func; join = func; split = func})
+let bank : Bank = {getIssuer = func; getReserve = func}
+let main : async (Account, Account) = async ({credit = func; getBalance = func; isCompatible = func; join = func; split = func}, {credit = func; getBalance = func; isCompatible = func; join = func; split = func})
 let show : (Text, Account) -> () = func
 let test : () -> async (Account, Account) = func
 let transfer : (Account, Account, Int) -> async () = func

samples/cheque.txt

@@ -18,8 +18,8 @@ Bank(100)
   Issuer()
     <= {hasIssued = func}
   Account(100)
-    <= {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}}
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {getIssuer = func; getReserve = func}
 test()
   -> async cheque.as:76.39-88.2
   <= async _
@@ -31,8 +31,8 @@ test()
     -> async cheque.as:7.32-7.51
     <= async _
 <- async cheque.as:7.32-7.51
-  <= {balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:77.17-77.40({balance = 100; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:77.17-77.40({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await cheque.as:78.12-78.35
 <- message split(10)
@@ -41,9 +41,9 @@ test()
     <= async _
 <- async cheque.as:32.39-35.4
   Account(10)
-    <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:78.12-78.35({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:78.12-78.35({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   -> message split(10)
   => await cheque.as:79.12-79.35
 <- message split(10)
@@ -52,35 +52,35 @@ test()
     <= async _
 <- async cheque.as:32.39-35.4
   Account(10)
-    <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-  <= {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
-<- await cheque.as:79.12-79.35({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-  show("reserve", {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+  <= {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}
+<- await cheque.as:79.12-79.35({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a1", {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("a1", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  show("a2", {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("a2", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
-  transfer({balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, 5)
+  transfer({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, 5)
     -> async cheque.as:64.79-67.2
     <= async _
   => await cheque.as:83.3-83.28
 <- async cheque.as:64.79-67.2
-  -> message invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  -> message invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
   => await cheque.as:65.16-65.53
-<- message invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-  invoice(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+<- message invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  invoice(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     -> async cheque.as:41.59-44.4
     <= async _
 <- async cheque.as:41.59-44.4
-  Cheque(5, {balance = 10; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
-    <= {current = 5; deposit = func}
-  <= {current = 5; deposit = func}
-<- await cheque.as:65.16-65.53({current = 5; deposit = func})
-  -> message deposit({current = 5; deposit = func})
+  Cheque(5, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+    <= {deposit = func}
+  <= {deposit = func}
+<- await cheque.as:65.16-65.53({deposit = func})
+  -> message deposit({deposit = func})
   <= ()
-<- message deposit({current = 5; deposit = func})
-  deposit({current = 5; deposit = func})
+<- message deposit({deposit = func})
+  deposit({deposit = func})
     -> message deposit()
     <= ()
 <- message deposit()
@@ -91,7 +91,7 @@ test()
   credit(5)
     <= ()
 <- await cheque.as:83.3-83.28()
-  show("reserve", {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  show("reserve", {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
     <= ()
   -> message getBalance()
   => await cheque.as:85.21-85.42
@@ -115,14 +115,14 @@ test()
 <- await cheque.as:86.21-86.42(15)
   showBalance("b2", 15)
     <= ()
-  <= ({balance = 5; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+  <= ({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
 -- Finished cheque.as:
 let Account : class Int -> Account = class
 let Bank : class Int -> Bank = class
 let Cheque : class (Int, Account) -> Cheque = class
 let Issuer : class () -> Issuer = class
-let bank : Bank = {getIssuer = func; getReserve = func; issuer = {hasIssued = func}; reserve = {balance = 80; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}}
-let main : async (Account, Account) = async ({balance = 5; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {balance = 15; credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
+let bank : Bank = {getIssuer = func; getReserve = func}
+let main : async (Account, Account) = async ({credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func}, {credit = func; deposit = func; getBalance = func; invoice = func; isCompatible = func; join = func; split = func})
 let show : (Text, Account) -> () = func
 let showBalance : (Text, Int) -> () = func
 let test : () -> async (Account, Account) = func

samples/counter.txt

@@ -8,7 +8,7 @@ let testDec : () -> ()
 let testRead : () -> ()
 -- Interpreting counter.as:
 Counter(10)
-  <= {c = 10; dec = func; read = func}
+  <= {dec = func; read = func}
 testDec()
   -> message dec()
   -> message dec()
@@ -288,7 +288,7 @@ testRead()
   <= ()
 -- Finished counter.as:
 let Counter : class Int -> Counter = class
-let c : Counter = {c = -10; dec = func; read = func}
+let c : Counter = {dec = func; read = func}
 let show : (Text, Int) -> () = func
 let showAsync : (Text, async Int) -> () = func
 let testDec : () -> () = func

samples/quicksort.txt

@@ -7,7 +7,7 @@ let cmpi : (Int, Int) -> Int
 let qs : QS<Int>
 -- Interpreting quicksort.as:
 QS(func)
-  <= {partition = func; quicksort = func; swap = func; trace = func}
+  <= {quicksort = func}
 quicksort([8, 3, 9, 5, 2], 0, 4)
   partition([8, 3, 9, 5, 2], 0, 4)
     trace([8, 3, 9, 5, 2])
@@ -100,5 +100,5 @@ quicksort([8, 3, 9, 5, 2], 0, 4)
 let QS : class <T>((T, T) -> Int) -> QS<T> = class
 let a : Array<Int> = [2, 3, 5, 8, 9]
 let cmpi : (Int, Int) -> Int = func
-let qs : QS<Int> = {partition = func; quicksort = func; swap = func; trace = func}
+let qs : QS<Int> = {quicksort = func}
 

src/arrange.ml

@@ -160,7 +160,7 @@ and dec d = match d.it with
     "FuncD" $$ [Atom (sharing s.it); id i] @ List.map typ_bind tp @ [pat p; typ t; exp e]
   | TypD (i, tp, t) ->
     "TypD" $$ [id i] @ List.map typ_bind tp @ [typ t]
-  | ClassD (i, j, tp, s, p, efs) ->
-    "ClassD" $$ id i :: id j :: List.map typ_bind tp @ [obj_sort s; pat p] @ List.map exp_field efs
+  | ClassD (i, j, tp, s, p, i', efs) ->
+    "ClassD" $$ id i :: id j :: List.map typ_bind tp @ [obj_sort s; pat p; id i'] @ List.map exp_field efs
 
 and prog prog = "BlockE"  $$ List.map dec prog.it                                                                       

src/async.ml

@@ -406,9 +406,9 @@ and t_dec' dec' =
           | _ -> failwith "async.ml t_dec': funcD3"
          end
     end
-  | ClassD (id, lab, typbinds, sort, pat, fields) ->
+  | ClassD (id, lab, typbinds, sort, pat, id', fields) ->
      let fields' = t_fields fields in             
-     ClassD (id, lab, t_typbinds typbinds, sort, t_pat pat, fields')
+     ClassD (id, lab, t_typbinds typbinds, sort, t_pat pat, id', fields')
 
 and t_decs decs = List.map t_dec decs