Every rational number can be represented as either a terminating or repeating decimal.

1/2 = 0.5 , 1/4 = 0.25 and 1/5 = 0.2 are examples of terminating decimals.

And, 1/3 = 0.(3) , 2/3 = 0.(6) , 5/6 = 0.8(3) and 3/7 = 0.(428571) are examples of repeating decimals.

Write a function, toDecimalString : Rational -> String , that outputs the decimal representation of a given rational number.

Your function MUST pass the following tests:

