Generics (ZTM)

generics.go

//--Summary:
//  Write a generic function to complete the existing code.
//
//--Requirements:
//* Write a single function named `clamp` that can restrict a value
//  to a specific range
//  - The function should work with floating point numbers, integers
//    and arbitrary type aliases
//  - Use the existing `clamp` function signature and comments as a
//    starting point
//
//--Notes:
//* The existing code relies on a proper implementation of the clamp function
//* The program will print "Exercise complete!" when properly implemented

package main

import "fmt"

type Distance int32
type Velocity float64

// The `clamp` function returns a value that has been "clamped"
// within a specific range of numbers. The `min` value is the
// minimum allowable and the `max` value is the maximum allowable.
// If the initial value lies within the range of `min` and `max`,
// then it should be returned as-is.
// Mathematically:
//   min <= value <= max

//--Requirements:
//* Write a single function named `clamp` that can restrict a value
//  to a specific range
//  - The function should work with floating point numbers, integers
//    and arbitrary type aliases
//  - Use the existing `clamp` function signature and comments as a
//  starting point
type ClampInput interface {
	int8 | uint32 | float32 | ~float64 | ~int32
}

func clamp[T ClampInput](num, min, max T) T {

	if num <= min {
		return min
	}
	if num >= min {
		return max
	}
	return num
}

func testClampInt8() {
	var (
		min int8 = -10
		max int8 = 10
	)
	if clamp(-30, min, max) != min {
		panic("clamp failed for int8")
	}
}

func testClampUint32() {
	var (
		min uint32 = 0
		max uint32 = 10
	)
	if clamp(20, min, max) != max {
		panic("clamp failed for uint32")
	}
}

func testClampFloat32() {
	var (
		min float32 = 5.5
		max float32 = 9.9
	)
	if clamp(0, min, max) != min {
		panic("clamp failed for float32")
	}
}

func testClampDistance() {
	var (
		min Distance = 0
		max Distance = 100
	)
	if clamp(Distance(99), min, max) != 99 {
		panic("clamp failed for Distance")
	}
}

func testClampVelocity() {
	var (
		min Velocity = 0.0
		max Velocity = 99.9
	)
	if clamp(Velocity(100), min, max) != max {
		panic("clamp failed for Velocity")
	}
}

func main() {
	testClampInt8()
	testClampUint32()
	testClampFloat32()
	testClampDistance()
	testClampVelocity()
	fmt.Println("Exercise complete!")
}
/*

$: go run generics.go
Output
panic: clamp failed for Distance

goroutine 1 [running]:
main.testClampDistance(...)
        /usr/local/go/src/GoLang/zerotomastery.io-golang/src/lectures/exercise/generics/generics.go:89
main.main()
        /usr/local/go/src/GoLang/zerotomastery.io-golang/src/lectures/exercise/generics/generics.go:107 +0x30
exit status 2

*/