(* Mandatory exercise 1, INF3110/4110, 2007 *) 


(* datatype declarations *) 

(* you might need to declare other datatypes in addition to the ones sketched here *) 

(* your datatype declaration for expressions *) 
datatype exp =  

(* your datatype declaration for statements *) 
datatype stmt =  

(* the datatype for program *) 
type prog = stmt list ; 

(* program state *) 
type state =   
fun getVal(x:var, s:state):int = 
fun putVal(x:var, n:int, s:state):state = 
fun stateToStr(s:state):string = 

(* your initial state with i=j=k=0 *)
val init = 

(* your ML representation of the sample program *) 
val sampleprog =  

(* evaluation of an expression in a state  *)
fun evalExp(e:exp,s:state):int = 

(* evaluation of a statement in a state *) 
fun eval(st:stmt, s:state):state = 

(* the interpret function *) 
fun interpret(p:prog,s:state):state = 

(* code to test your implementation *) 
(print "(*** Program start ***)\n";
print ("Initial state: \t"^(stateToStr(init)));
print ("Final state: \t"^(stateToStr(interpret(sampleprog,init))));
print "(*** Program end ***)\n");