Module checkit {
      \\ Inventories are objects with keys and values, or keys (used as read only values)
      \\ They use hash function.
      \\ Function TwoKeys return Inventory object (as a pointer to object)
      Function TwoKeys {
            Inventory Alfa="key1":=100, "key2":=200
            =Alfa
      }
      M=TwoKeys()
      Print Type$(M)="Inventory"
      \\ Normal Use:
            \\ Inventories Keys are case sensitive
            \\ M2000 identifiers are not case sensitive
      Print M("key1"), m("key2")
      \\ numeric values can convert to strings
      Print M$("key1"), m$("key2")
      \\ Iteration
      N=Each(M)
      While N {
            Print Eval(N)  ' prints 100, 200 as number
            Print M(N^!)  ' The same using index N^
      }
      N=Each(M)
      While N {
            Print Eval$(N)  ' prints  100, 200 as strings
            Print M$(N^!)  ' The same using index N^
      }
      N=Each(M)
      While N {
            Print Eval$(N, N^)  ' Prints Keys
      }
      \\ double iteration
      Append M, "key3":=500
      N=Each(M, 1, -1)  ' start to end
      N1=Each(M, -1, 1) ' end to start
      \\ 3x3 prints
      While N {
            While N1 {
                  Print format$("{0}*{1}={2}", Eval(N1), Eval(N), Eval(N1)*Eval(N))
            }
      }
      \\ sort results from lower product to greater product (3+2+1, 6 prints only)
      N=Each(M, 1, -1)
      While N {
            N1=Each(M, N^+1, -1)
            While N1 {
                  Print format$("{0}*{1}={2}", Eval(N1), Eval(N), Eval(N1)*Eval(N))
            }
      }
      N=Each(M)
      N1=Each(M,-2, 1)  ' from second from end to start
      \\ print only 2 values. While block ends when one iterator finish
      While N, N1 {
            Print Eval(N1)*Eval(N)
      }
}
Checkit