CODEWITHSUNDEEP
scala
Tyrion Lannister
Tyrion Lannister

Reputation: 221

Scala Recursive Function with patterns

When creating a function with recursion on Pattern matching its throws the below error, but when created with a method it works fine. Can you please help me understand.

val power: (Int, Int) => Int = (base: Int, exp: Int) => {
    exp match {
        case 0 => 1
        case 1 => `base`
        case e => `base` * power(`base`, e - 1) 
    }
}

The code above shows produces the error: "Forward reference extends over definition of value". But the code below works fine:

def func1(base: Int, exp: Int): Int = {
    exp match {
        case 0 => 1
        case 1 => `base`
        case e => `base` * func1(`base`, e - 1)
    }
}

Upvotes: 1

Views: 144

Answers (1)

bjfletcher
bjfletcher

Reputation: 11508

Try adding lazy to the front of the val in order that the expression is set rather than executed. Then when it is executed by calling it, it will already have been set.

Upvotes: 2

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