Map Key Helper

The comparable constraint allows a generic helper to use map keys.

map_key_helper.go

package main

import "fmt"

// Generic shape: Lookup[K comparable, V any](items map[K]V, key K) (V, bool)
func LookupScore(items map[string]int, key string) (int, bool) {
	value, ok := items[key]
	return value, ok
}

func main() {
	var key = 
	scores := map[string]int{"alpha": 10, "beta": 20}
	value, ok := LookupScore(scores, key)

	fmt.Println("key=", key)
	fmt.Println("found=", ok)
	fmt.Println("value=", value)
}

package main

import "fmt"

// Generic shape: Lookup[K comparable, V any](items map[K]V, key K) (V, bool)
func LookupScore(items map[string]int, key string) (int, bool) {
	value, ok := items[key]
	return value, ok
}

func main() {
	var key = 
	scores := map[string]int{"alpha": 10, "beta": 20}
	value, ok := LookupScore(scores, key)

	fmt.Println("key=", key)
	fmt.Println("found=", ok)
	fmt.Println("value=", value)
}

package main

import "fmt"

// Generic shape: Lookup[K comparable, V any](items map[K]V, key K) (V, bool)
func LookupScore(items map[string]int, key string) (int, bool) {
	value, ok := items[key]
	return value, ok
}

func main() {
	var key = 
	scores := map[string]int{"alpha": 10, "beta": 20}
	value, ok := LookupScore(scores, key)

	fmt.Println("key=", key)
	fmt.Println("found=", ok)
	fmt.Println("value=", value)
}

comparable Map keys must be comparable, so a generic map helper can require `K comparable`. The trace uses a concrete string-keyed map and shows the generic shape in a comment.