66 lines
1.9 KiB
Go
66 lines
1.9 KiB
Go
package iter
|
|
|
|
import (
|
|
"sync"
|
|
|
|
"github.com/sourcegraph/conc/internal/multierror"
|
|
)
|
|
|
|
// Mapper is an Iterator with a result type R. It can be used to configure
|
|
// the behaviour of Map and MapErr. The zero value is safe to use with
|
|
// reasonable defaults.
|
|
//
|
|
// Mapper is also safe for reuse and concurrent use.
|
|
type Mapper[T, R any] Iterator[T]
|
|
|
|
// Map applies f to each element of input, returning the mapped result.
|
|
//
|
|
// Map always uses at most runtime.GOMAXPROCS goroutines. For a configurable
|
|
// goroutine limit, use a custom Mapper.
|
|
func Map[T, R any](input []T, f func(*T) R) []R {
|
|
return Mapper[T, R]{}.Map(input, f)
|
|
}
|
|
|
|
// Map applies f to each element of input, returning the mapped result.
|
|
//
|
|
// Map uses up to the configured Mapper's maximum number of goroutines.
|
|
func (m Mapper[T, R]) Map(input []T, f func(*T) R) []R {
|
|
res := make([]R, len(input))
|
|
Iterator[T](m).ForEachIdx(input, func(i int, t *T) {
|
|
res[i] = f(t)
|
|
})
|
|
return res
|
|
}
|
|
|
|
// MapErr applies f to each element of the input, returning the mapped result
|
|
// and a combined error of all returned errors.
|
|
//
|
|
// Map always uses at most runtime.GOMAXPROCS goroutines. For a configurable
|
|
// goroutine limit, use a custom Mapper.
|
|
func MapErr[T, R any](input []T, f func(*T) (R, error)) ([]R, error) {
|
|
return Mapper[T, R]{}.MapErr(input, f)
|
|
}
|
|
|
|
// MapErr applies f to each element of the input, returning the mapped result
|
|
// and a combined error of all returned errors.
|
|
//
|
|
// Map uses up to the configured Mapper's maximum number of goroutines.
|
|
func (m Mapper[T, R]) MapErr(input []T, f func(*T) (R, error)) ([]R, error) {
|
|
var (
|
|
res = make([]R, len(input))
|
|
errMux sync.Mutex
|
|
errs error
|
|
)
|
|
Iterator[T](m).ForEachIdx(input, func(i int, t *T) {
|
|
var err error
|
|
res[i], err = f(t)
|
|
if err != nil {
|
|
errMux.Lock()
|
|
// TODO: use stdlib errors once multierrors land in go 1.20
|
|
errs = multierror.Join(errs, err)
|
|
errMux.Unlock()
|
|
}
|
|
})
|
|
return res, errs
|
|
}
|