SCALA

sealed trait CFrac case class OneByNumber(num: Int) extends CFrac case class NumPlusContFrac(num: Int, contFrac: CFrac) extends CFrac case class Frac(num: Int, contFrac: CFrac) extends CFrac USING ABOVE:

SHOW THAT IT PASSES ALL TESTs:

Implement a function double_of_cfrac that takes in a continued fraction expressed using the inductive definition above and evaluates the corresponding double precision number.

Restrictions:

You are required to use case pattern matching.

Your function need not be tail recursive.

Forbidden: use of loops, mutable (vars), return statement.

Your program should pass the following tests:

val g1 = NumPlusContFrac(2,NumPlusContFrac(3,OneByNumber(4)))

testWithMessage(double_of_cfrac(g1), 0.43333333, " # 1")

val g2 = OneByNumber(2)

testWithMessage(double_of_cfrac(g2), 0.5, " # 2")

val g3 = NumPlusContFrac(3, NumPlusContFrac(-1, OneByNumber(5)))

testWithMessage(double_of_cfrac(g3), 0.57142857, " # 3")

val g4 = NumPlusContFrac(1, OneByNumber(-2))

testWithMessage(double_of_cfrac(g4), 2.0, " # 4")