inital commit

typeutils/optional.go

@@ -0,0 +1,77 @@
+package typeutils
+
+// CTORS BEGIN
+func Some[T any](value T) Optional[T] {
+	return Optional[T]{value, true}
+}
+
+func None[T any]() Optional[T] {
+	return Optional[T]{present: false}
+}
+
+// Because None has no type passing a value of desired type might be preferred syntax over providing type on the function call
+func None_t[T any](T) Optional[T] {
+	return Optional[T]{present: false}
+}
+
+// CTORS END
+
+func (opt Optional[T]) Is_some() bool { return opt.present }
+func (opt Optional[T]) Is_none() bool { return !opt.present }
+
+func (opt Optional[T]) Has_value() bool { return opt.Is_some() }
+
+// UNWRAPPABLE INTERFACE BEGIN
+func (opt Optional[T]) Expect(msg string) T {
+	if opt.present {
+		return opt.value
+	}
+	panic(msg)
+}
+
+func (opt Optional[T]) Unwrap() T {
+	if opt.present {
+		return opt.value
+	}
+	panic("Tried unwrapping an Optional that did not have a value!")
+}
+
+func (opt Optional[T]) Unwrap_or(val T) T {
+	if opt.present {
+		return opt.value
+	}
+	return val
+}
+
+func (opt Optional[T]) Unwrap_or_default() T {
+	if opt.present {
+		return opt.value
+	}
+	var res T
+	return res
+}
+
+func (opt Optional[T]) Unwrap_or_else(f func() T) T {
+	if opt.present {
+		return opt.value
+	}
+	return f()
+}
+
+// UNWRAPPABLE INTERFACE END
+
+// transforms Some(v) to Ok(v), and None to Err(err)
+func (opt Optional[T]) Ok_or(err error) Result[T] {
+	if opt.present {
+		return Ok(opt.value)
+	}
+	return Err[T](err)
+}
+
+// transforms Some(v) to Ok(v), and None to a value of Err using the provided function
+func (opt Optional[T]) Ok_or_else(f func() error) Result[T] {
+	if opt.present {
+		return Ok(opt.value)
+	}
+	return Err[T](f())
+}