Proposal: support error handling on mapping functions (such as slices.Map) #264
Description
Usecase: the current implementation of mapping/iterator functions such as map, filter, etc, does not offer error handling. And so if the iteratee function encounters an error case there's no standard way of handling it.
Proposal: extend Map, Filter and similar iterator functions with an error-handling variant of the function, where the iteratee may return an error in which case the iteration breaks and an error is returned from the iterator function.
Example:
// MapErr is similar to lo.Map, but handles error in iteratee function
func MapErr[T any, R any](collection []T, iteratee func(T, int) (R, error)) ([]R, error) {
result := make([]R, len(collection))
for i, item := range collection {
res, err := iteratee(item, i)
if err != nil {
return nil, err
}
result[i] = res
}
return result, nil
}usage:
package main
import (
"fmt"
"github.com/otterize/lox"
"strings"
)
func main() {
names, err := lox.MapErr([]string{"Otter", "Other", "Utter"}, func(s string, i int) (string, error) {
if s == "" {
return "", fmt.Errorf("empty name")
}
return s, nil
})
if err != nil {
panic(err)
}
fmt.Printf("Names: %s", strings.Join(names, ","))
}this example is based on my own implementation at https://github.com/otterize/lox (which I used for my own projects' purpose), and if accepted I'd love to extend it further and suggest it as part of the package.