fix: map function

cmd/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"strings"
+	"strconv"
 
 	"github.com/araujo88/lambda-go/pkg/core"
 	"github.com/araujo88/lambda-go/pkg/predicate"
@@ -14,6 +15,7 @@ func main() {
 	// Example: Doubling the values in a slice of integers
 	intSlice := []int{1, 2, 3, 4, 5}
 	doubled := core.Map(intSlice, func(x int) int { return x * 2 })
+	stringNumbers := core.Map(intSlice, strconv.Itoa)
 	sum := core.Foldr(func(x int, acc int) int { return x + acc }, 0, intSlice)
 	greaterThan2 := predicate.Filter(intSlice, func(x int) bool {
 		if x > 2 {
@@ -26,6 +28,7 @@ func main() {
 	fmt.Println("Head:", utils.Head(intSlice))
 	fmt.Println("Tail:", utils.Tail(intSlice))
 	fmt.Println("Doubled Integers:", doubled)
+	fmt.Println(stringNumbers)
 	fmt.Println("Sum of integers:", sum)
 	fmt.Println("Filtering elements greater than 2:", greaterThan2)
 

pkg/core/core.go

@@ -2,16 +2,13 @@ package core
 
 import "golang.org/x/exp/constraints"
 
-// mapSlice applies a function to each element of a slice of type T and returns a new slice of the same type T.
-func Map[T any](slice []T, function func(T) T) []T {
-	newSlice := make([]T, len(slice))
-	if len(slice) == 0 {
-		return []T{}
-	}
-	for i, v := range slice {
-		newSlice[i] = function(v)
-	}
-	return newSlice
+// mapSlice applies a function to each element of a slice of type T and returns a new slice of type U.
+func Map[T any, U any](slice []T, function func(T) U) []U {
+    newSlice := make([]U, len(slice))
+    for i, v := range slice {
+        newSlice[i] = function(v)
+    }
+    return newSlice
 }
 
 // Foldr recursively folds a slice from the right using a function and an initial accumulator value.