Split optional.go into more files.

pkg/opt/none.go

@@ -0,0 +1,47 @@
+package opt
+
+// None represents the absence of a value.
+type None[V any] struct {
+}
+
+// Assert that None[V] implements Optional[V]
+var _ Optional[any] = None[any]{}
+
+func (n None[V]) Present() bool {
+	return false
+}
+
+func (n None[V]) Get() (V, bool) {
+	var zero V
+	return zero, false
+}
+
+func (n None[V]) GetOrZero() V {
+	var zero V
+	return zero
+}
+
+func (n None[V]) GetOrDefault(defaultValue V) V {
+	return defaultValue
+}
+
+func (n None[V]) GetOrFunc(f func() V) V {
+	return f()
+}
+
+func (n None[V]) Filter(_ func(V) bool) Optional[V] {
+	return n
+}
+
+func (n None[V]) IfPresent(_ func(V)) bool {
+	return false
+}
+
+func (n None[V]) IfPresentElse(_ func(V), f func()) bool {
+	f()
+	return false
+}
+
+func (n None[V]) String() string {
+	return "None"
+}

pkg/opt/optional.go

@@ -2,6 +2,40 @@ package opt
 
 import "fmt"
 
+// Optional is a generic type that takes one type parameter V and represents a value that may or may not be present.
+// It is similar to Java's Optional type.
+type Optional[V any] interface {
+	fmt.Stringer
+
+	// Present returns true if the Optional contains a value, false otherwise.
+	Present() bool
+
+	// Get returns the value contained in the Optional and an indicator of whether the Optional is empty.
+	// If the Optional is empty, the value returned is the zero value of type V.
+	Get() (V, bool)
+
+	// GetOrZero returns the value contained in the Optional, or the zero value of type V if the Optional is empty.
+	GetOrZero() V
+
+	// GetOrDefault returns the value contained in the Optional, or the provided default value if the Optional is empty.
+	GetOrDefault(defaultValue V) V
+
+	// GetOrFunc returns the value contained in the Optional, or the result of calling the provided function if the Optional is empty.
+	GetOrFunc(func() V) V
+
+	// IfPresent calls the provided function with the value contained in the Optional if the Optional is not empty.
+	// Returns true if the function was called, false otherwise.
+	IfPresent(func(V)) bool
+
+	// IfPresentElse calls the first function with the value contained in the Optional if the Optional is not empty, or the second function otherwise.
+	// Returns true if the first function was called, false otherwise.
+	IfPresentElse(func(V), func()) bool
+
+	// Filter returns an Optional containing the value contained in the Optional if the provided predicate returns true for that value.
+	// If the Optional is empty, an empty Optional is returned.
+	Filter(func(V) bool) Optional[V]
+}
+
 // Empty returns an empty Optional (None).
 func Empty[V any]() Optional[V] {
 	return None[V]{}
@@ -103,126 +137,3 @@ func MaybeMap[V, U any](o Optional[V], mapper func(V) (U, bool)) Optional[U] {
 	}
 	return Empty[U]()
 }
-
-// Optional is a generic type that takes one type parameter V and represents a value that may or may not be present.
-// It is similar to Java's Optional type.
-type Optional[V any] interface {
-	fmt.Stringer
-
-	// Present returns true if the Optional contains a value, false otherwise.
-	Present() bool
-
-	// Get returns the value contained in the Optional and an indicator of whether the Optional is empty.
-	// If the Optional is empty, the value returned is the zero value of type V.
-	Get() (V, bool)
-
-	// GetOrZero returns the value contained in the Optional, or the zero value of type V if the Optional is empty.
-	GetOrZero() V
-
-	// GetOrDefault returns the value contained in the Optional, or the provided default value if the Optional is empty.
-	GetOrDefault(defaultValue V) V
-
-	// GetOrFunc returns the value contained in the Optional, or the result of calling the provided function if the Optional is empty.
-	GetOrFunc(func() V) V
-
-	// IfPresent calls the provided function with the value contained in the Optional if the Optional is not empty.
-	// Returns true if the function was called, false otherwise.
-	IfPresent(func(V)) bool
-
-	// IfPresentElse calls the first function with the value contained in the Optional if the Optional is not empty, or the second function otherwise.
-	// Returns true if the first function was called, false otherwise.
-	IfPresentElse(func(V), func()) bool
-
-	// Filter returns an Optional containing the value contained in the Optional if the provided predicate returns true for that value.
-	// If the Optional is empty, an empty Optional is returned.
-	Filter(func(V) bool) Optional[V]
-}
-
-// None is an Optional that represents the absence of a value.
-type None[V any] struct {
-}
-
-func (n None[V]) Present() bool {
-	return false
-}
-
-func (n None[V]) Get() (V, bool) {
-	var zero V
-	return zero, false
-}
-
-func (n None[V]) GetOrZero() V {
-	var zero V
-	return zero
-}
-
-func (n None[V]) GetOrDefault(defaultValue V) V {
-	return defaultValue
-}
-
-func (n None[V]) GetOrFunc(f func() V) V {
-	return f()
-}
-
-func (n None[V]) Filter(_ func(V) bool) Optional[V] {
-	return n
-}
-
-func (n None[V]) IfPresent(_ func(V)) bool {
-	return false
-}
-
-func (n None[V]) IfPresentElse(_ func(V), f func()) bool {
-	f()
-	return false
-}
-
-func (n None[V]) String() string {
-	return "None"
-}
-
-// Some is an Optional that represents the presence of a value.
-type Some[V any] struct {
-	Value V
-}
-
-func (s Some[V]) Present() bool {
-	return true
-}
-
-func (s Some[V]) Get() (V, bool) {
-	return s.Value, true
-}
-
-func (s Some[V]) GetOrZero() V {
-	return s.Value
-}
-
-func (s Some[V]) GetOrDefault(_ V) V {
-	return s.Value
-}
-
-func (s Some[V]) GetOrFunc(_ func() V) V {
-	return s.Value
-}
-
-func (s Some[V]) Filter(f func(V) bool) Optional[V] {
-	if f(s.Value) {
-		return s
-	}
-	return Empty[V]()
-}
-
-func (s Some[V]) IfPresent(f func(V)) bool {
-	f(s.Value)
-	return true
-}
-
-func (s Some[V]) IfPresentElse(f func(V), _ func()) bool {
-	f(s.Value)
-	return true
-}
-
-func (s Some[V]) String() string {
-	return fmt.Sprintf("Some(%#v)", s.Value)
-}

pkg/opt/some.go

@@ -0,0 +1,52 @@
+package opt
+
+import "fmt"
+
+// Some represents the presence of a value.
+type Some[V any] struct {
+	Value V
+}
+
+// Assert that Some[V] implements Optional[V]
+var _ Optional[any] = Some[any]{}
+
+func (s Some[V]) Present() bool {
+	return true
+}
+
+func (s Some[V]) Get() (V, bool) {
+	return s.Value, true
+}
+
+func (s Some[V]) GetOrZero() V {
+	return s.Value
+}
+
+func (s Some[V]) GetOrDefault(_ V) V {
+	return s.Value
+}
+
+func (s Some[V]) GetOrFunc(_ func() V) V {
+	return s.Value
+}
+
+func (s Some[V]) Filter(f func(V) bool) Optional[V] {
+	if f(s.Value) {
+		return s
+	}
+	return Empty[V]()
+}
+
+func (s Some[V]) IfPresent(f func(V)) bool {
+	f(s.Value)
+	return true
+}
+
+func (s Some[V]) IfPresentElse(f func(V), _ func()) bool {
+	f(s.Value)
+	return true
+}
+
+func (s Some[V]) String() string {
+	return fmt.Sprintf("Some(%#v)", s.Value)
+}