Map declaration in Scilla

gistfile1.txt

contract Maps()

field a: Map ByStr20 String = Emp ByStr20 String          (*declaring variable a with no value*)

field b: Map ByStr20 Int32 = let c = Emp ByStr20 Int32 in 
                               let d = 0x1234567890123456789012345678901234567896 in 
                               let e = Int32 5 in 
                               builtin put c d e          (*declaring variable b with fixed value*)

                               
transition update_value()

   f = 0xffff567890123456789012345678901234567896;
   g = "hello";
   h = Int32 6; 
   
   (*updating variable a*)
   i <- a;
   j = builtin put i f g; 
   a:= j; (*Puts a new entry in the previously empty map a*)
   
   (*updating variable b*)
   k <- b; 
   l = builtin put k f h; 
   b:= l; (*updates a new entry in the map b along with the existing entries*)


   (*to extract the entry stored against a key in a map, one can use the following method*)

   m = builtin get k f; (*m is not equal to the value h stored, but is equal to the Option h. We'll need to further extract value from here*)
   
   match m with 
       | Some n => (*this variable n now contains the value originally stored in the map*)
           (*perform relevant operations on n*)
       end
 

end