-- ===========================================================
--> CafeOBJ codes for lecture 4
-- ===========================================================
--
-- See misc.mod, ast.mod, interpreter.mod, vm.mod 
-- and compiler.mod in the sub directory of /minila
--

--
-- loads necessary files
--

in minila/misc
in minila/ast
in minila/interpreter
in minila/vm

--
-- Quick Reminder
--

open INTERPRETER
  op p1 : -> Stm .
  eq p1 = v(0) := 1 ;
          v(1) := 1 ;
          while v(1) << 10 || v(1) === 10 do
            v(0) := v(0) ** v(1) ;
            v(1) := v(1) ++ 1 ;
          od .
  red interpret(p1) .
close

open VM
  op cl1 : -> CList .
  eq cl1 = push(1) | store(v(0)) | push(1) | store(v(1)) | load(v(1)) |
           push(10) | equal | load(v(1)) | push(10) | lessThan | or |
           jumpOnCond(2) | jump(10) | load(v(1)) | load(v(0)) |
           multiply | store(v(0)) | load(v(1)) | push(1) | add |
           store(v(1)) | bjump(17) | quit | clnil .
  red vm(cl1) .
close


--
-- Interpretation of Expressions
--

open INTERPRETER
  op env : -> Env .
  eq env = update(v(1),8,update(v(0),3,empEnv)) .
  red evalExp(1,env) .
  red evalExp(v(0),env) .
  red evalExp(v(1),env) .
  red evalExp(v(2),env) .
  red evalExp(v(1) ++ v(0),env) .
  red evalExp(v(1) -- v(0),env) .
  red evalExp(v(1) ** v(0),env) .
  red evalExp(v(1) // v(0),env) .
  red evalExp(v(1) %% v(0),env) .
  red evalExp(v(1) === v(0),env) .
  red evalExp(v(1) !== v(0),env) .
  red evalExp(v(1) << v(0),env) .
  red evalExp(v(1) >> v(0),env) .
  red evalExp(v(1) >> v(0) && v(1) === v(0),env) .
  red evalExp(v(1) >> v(0) || v(1) === v(0),env) .
close

--
-- Interpretation of Statements
--
open INTERPRETER
  op env : -> Env .
  eq env = update(v(1),8,update(v(0),3,empEnv)) .
  red eval(estm,env) .
  red eval(v(0) := 5 ;,env) .
  red eval(v(2) := 5 ;,env) .
  red eval(if v(0) === v(1)
           then v(0) := 0 ; else v(0) := v(1) ; fi,env) .
  -- red eval(if v(1) %% v(0) === 2
  --          then v(0) := 0 ; else v(0) := v(1) ; fi,env) .
  red eval(v(3) := 0 ; v(2) := v(0) ; 
           while v(2) << v(1) || v(2) === v(1) do
             v(3) := v(3) ++ v(2) ;
             v(2) := v(2) ++ 1 ;
           od, env) .
   -- red eval(v(3) := 0 ; <-- A space SHOULD be inserted between 0 and ;.
   --          for v(2) v(0) v(1) do
   --            v(3) := v(3) ++ v(2) ;
   --          od, env) .
close


--
-- Virtual Machine
--

open VM
  op env : -> Env .
  eq env = update(v(1),8,update(v(0),3,empEnv)) .
  red exec(quit | clnil,0,empstk,env) .
  red exec(push(5) | store(v(0)) | quit | clnil,0,empstk,env) .
  red exec(push(5) | store(v(2)) | quit | clnil,0,empstk,env) .
  red exec(load(v(0)) | load(v(1))  | equal       | jumpOnCond(2) |
           jump(4)    | push(0)     | store(v(0)) | jump(3)       |
           load(v(1)) | store(v(0)) | quit        | clnil
           ,0,empstk,env) .
  red exec(push(0)     | store(v(3)) | load(v(0)) | store(v(2))   |
           load(v(2))  | load(v(1))  | lessThan   | load(v(2))    |
           load(v(1))  | equal       | or         | jumpOnCond(2) |
           jump(10)    | load(v(3))  | load(v(2)) | add           |
           store(v(3)) | load(v(2))  | push(1)    | add           |
           store(v(2)) | bjump(17)   | quit       | clnil,
           0,empstk,env) .
close

-- ===========================================================
-- end end end
-- ===========================================================