Go Patterns: Common patterns for the Go language.

recursiveAnonLambdas.go

package main

import (
    "fmt"
    "math"
)

func Sqrt(x float64) float64 {
	const deltaCorrectionThreshold = .000000000000000005
    var NewtonSquareRootRecursive func(float64, float64) float64
    NewtonSquareRootRecursive = func(x, z0 float64) float64 {
        z1 := 0.5 * (z0 + x / z0)
        if math.Abs(z1-z0)< deltaCorrectionThreshold {
            return z1
        }
	    return NewtonSquareRootRecursive(x, z1)
    }
    return NewtonSquareRootRecursive(x, 1.5)
}

func main() {
    fmt.Println("Square-root (Newton's Method):",Sqrt(2))
}