vendor

vendor/github.com/samber/mo/fold.go

@@ -0,0 +1,28 @@
+package mo
+
+// Foldable represents a type that can be folded into a single value
+// based on its state.
+//
+// - T: the type of the value in the failure state (e.g., an error type).
+// - U: the type of the value in the success state.
+type Foldable[T any, U any] interface {
+	leftValue() T
+	rightValue() U
+	hasLeftValue() bool
+}
+
+// Fold applies one of the two functions based on the state of the Foldable type,
+// and it returns the result of applying either successFunc or failureFunc.
+//
+// - T: the type of the failure value (e.g., an error type)
+// - U: the type of the success value
+// - R: the type of the return value from the folding functions
+//
+// successFunc is applied when the Foldable is in the success state (i.e., isLeft() is false).
+// failureFunc is applied when the Foldable is in the failure state (i.e., isLeft() is true).
+func Fold[T, U, R any](f Foldable[T, U], successFunc func(U) R, failureFunc func(T) R) R {
+	if f.hasLeftValue() {
+		return failureFunc(f.leftValue())
+	}
+	return successFunc(f.rightValue())
+}