added buffer argument to OfSeq and OfSeq2

filter.go

@@ -1,6 +1,6 @@
 package channel
 
-func Filter[T any](source <-chan T, filter func(T) bool) <-chan T {
+func FilterSuccessive[T any](source <-chan T, filter func(T) bool) <-chan T {
 	out := make(chan T, cap(source))
 
 	go func() {
@@ -14,3 +14,26 @@ func Filter[T any](source <-chan T, filter func(T) bool) <-chan T {
 
 	return out
 }
+
+func Filter[T any](source <-chan T, filter func(T) bool) <-chan T {
+	return FilterPreserveOrderWithRunner(source, getDefaultRunner(), filter)
+}
+
+func FilterPreserveOrderWithRunner[T any](source <-chan T, runner Runner, filter func(T) bool) <-chan T {
+	type FilteredValue[T any] struct {
+		Value  T
+		Filter bool
+	}
+
+	mappedValues := MapPreserveOrderWithRunner(source, runner, func(value T) FilteredValue[T] {
+		return FilteredValue[T]{Value: value, Filter: filter(value)}
+	})
+
+	filteredValues := FilterSuccessive(mappedValues, func(filteredValue FilteredValue[T]) bool {
+		return filteredValue.Filter
+	})
+
+	return MapSuccessive(filteredValues, func(filteredValue FilteredValue[T]) T {
+		return filteredValue.Value
+	})
+}

flat.go

@@ -15,6 +15,21 @@ func FlatSlice[T any](source <-chan []T) <-chan T {
 	return out
 }
 
+func FlatMap[K comparable, V, T any](source <-chan map[K]V, unmapper func(key K, value V) T) <-chan T {
+	out := make(chan T, cap(source))
+
+	go func() {
+		defer close(out)
+		for slice := range source {
+			for k, v := range slice {
+				out <- unmapper(k, v)
+			}
+		}
+	}()
+
+	return out
+}
+
 func FlatChan[T any](source <-chan <-chan T) <-chan T {
 	out := make(chan T, cap(source))
 

go.mod

@@ -1,3 +1,3 @@
 module git.milar.in/milarin/channel
 
-go 1.18
+go 1.23

of.go

@@ -2,6 +2,7 @@ package channel
 
 import (
 	"context"
+	"iter"
 	"time"
 )
 
@@ -58,7 +59,7 @@ func OfFunc[T any](ctx context.Context, buffer int, f func() T) <-chan T {
 func OfMap[K comparable, V, T any](m map[K]V, unmapper func(K, V) T) <-chan T {
 	out := make(chan T, len(m))
 
-	defer func() {
+	go func() {
 		defer close(out)
 		for k, v := range m {
 			out <- unmapper(k, v)
@@ -67,3 +68,32 @@ func OfMap[K comparable, V, T any](m map[K]V, unmapper func(K, V) T) <-chan T {
 
 	return out
 }
+
+// OfSeq returns a channel containing all values provided by the iterator
+func OfSeq[T any](seq iter.Seq[T], buffer int) <-chan T {
+	out := make(chan T, buffer)
+
+	go func() {
+		defer close(out)
+		for v := range seq {
+			out <- v
+		}
+	}()
+
+	return out
+}
+
+// OfSeq2 returns a channel containing the return values of the unmapper function
+// when provided with the values of the iterator
+func OfSeq2[K comparable, V, T any](seq iter.Seq2[K, V], buffer int, unmapper func(K, V) T) <-chan T {
+	out := make(chan T, buffer)
+
+	go func() {
+		defer close(out)
+		for key, value := range seq {
+			out <- unmapper(key, value)
+		}
+	}()
+
+	return out
+}

result.go

@@ -13,12 +13,12 @@ func ResultOf[T any](value T, err error) Result[T] {
 	return Result[T]{value: &value, err: nil}
 }
 
-func WrapMapFunc[I, O any](f func(I) (O, error)) func(I) Result[O] {
+func WrapResultOutputFunc[I, O any](f func(I) (O, error)) func(I) Result[O] {
 	return func(i I) Result[O] { return ResultOf(f(i)) }
 }
 
-func WrapMapResultFunc[I, O any](f func(I) (O, error)) func(Result[I]) Result[O] {
-	resFunc := WrapMapFunc(f)
+func WrapResultFunc[I, O any](f func(I) (O, error)) func(Result[I]) Result[O] {
+	resFunc := WrapResultOutputFunc(f)
 	nilValue := *new(O)
 	return func(r Result[I]) Result[O] {
 		v, err := r.Get()
@@ -46,10 +46,13 @@ func (r Result[T]) GetOrDefault(defaultValue T) T {
 }
 
 func (r Result[T]) Get() (T, error) {
+	if r.err != nil {
+		return *new(T), r.err
+	}
 	return *r.value, r.err
 }
 
-func (r Result[T]) GetSafe() T {
+func (r Result[T]) GetUnsafe() T {
 	if r.err != nil {
 		panic(r.err)
 	}
@@ -61,7 +64,7 @@ func (r Result[T]) Err() error {
 }
 
 func FilterSuccess[T any](source <-chan Result[T]) <-chan T {
-	succeeded := Filter(source, func(r Result[T]) bool { return r.Success() })
+	succeeded := Filter(source, Result[T].Success)
 
 	return MapSuccessive(succeeded, func(r Result[T]) T {
 		v, _ := r.Get()
@@ -70,7 +73,7 @@ func FilterSuccess[T any](source <-chan Result[T]) <-chan T {
 }
 
 func FilterFail[T any](source <-chan Result[T]) <-chan T {
-	failed := Filter(source, func(r Result[T]) bool { return r.Fail() })
+	failed := Filter(source, Result[T].Fail)
 
 	return MapSuccessive(failed, func(r Result[T]) T {
 		v, _ := r.Get()
@@ -91,7 +94,7 @@ func FilterResults[T any](source <-chan Result[T]) (succeeded <-chan T, failed <
 				fail <- r.Err()
 				continue
 			}
-			succ <- r.GetSafe()
+			succ <- r.GetUnsafe()
 		}
 	}()