inital commit

typeutils/interfaces.go

@@ -0,0 +1,43 @@
+package typeutils
+
+// Created to abstract over Is_some and Is_ok
+type ValueContainer interface {
+	Has_value() bool
+}
+
+type Unwrappable[T any] interface {
+	Expect(string) T           // panics with a provided custom message
+	Unwrap() T                 // panics with a generic message
+	Unwrap_or(T) T             // returns the provided default value
+	Unwrap_or_default() T      // returns the default value of the type T
+	Unwrap_or_else(func() T) T // returns the result of evaluating the provided function
+}
+
+// Both an Optional and Result is an Option
+type Option[T any] interface {
+	Unwrappable[T]
+}
+
+type OptionalI[T any] interface {
+	Is_some() bool
+	Is_none() bool
+	Ok_or(error) Result[T]
+	Ok_or_else(func() error) Result[T]
+}
+
+type ResultI[T any] interface {
+	Is_ok() bool
+	Is_err() bool
+	Ok() Optional[T]
+	Err() Optional[error]
+}
+
+// Ensure compile time the interfaces are implemented
+var (
+	_ Option[any]    = (*Optional[any])(nil)
+	_ Option[any]    = (*Result[any])(nil)
+	_ OptionalI[any] = (*Optional[any])(nil)
+	_ ResultI[any]   = (*Result[any])(nil)
+	_ ValueContainer = (*Optional[any])(nil)
+	_ ValueContainer = (*Result[any])(nil)
+)

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())
+}

typeutils/result.go

@@ -0,0 +1,92 @@
+package typeutils
+
+// CTORS BEGIN
+func Ok[T any](value T) Result[T] {
+	return Result[T]{value: value, err: nil}
+}
+
+func Err[T any](err error) Result[T] {
+	return Result[T]{err: err}
+}
+
+func Err_t[T any](err error, x T) Result[T] {
+	return Result[T]{err: err}
+}
+
+// CTORS END
+
+func (res Result[T]) Is_ok() bool  { return res.err == nil }
+func (res Result[T]) Is_err() bool { return res.err != nil }
+
+func (res Result[T]) Has_value() bool { return res.Is_ok() }
+
+// UNWRAPPABLE INTERFACE
+func (res Result[T]) Expect(msg string) T {
+	if res.err == nil {
+		return res.value
+	}
+	panic(msg)
+}
+
+func (res Result[T]) Unwrap() T {
+	if res.err == nil {
+		return res.value
+	}
+	panic("Tried unwrapping a Result that had an error a value!")
+}
+
+func (res Result[T]) Unwrap_or(val T) T {
+	if res.err == nil {
+		return res.value
+	}
+	return val
+}
+
+func (res Result[T]) Unwrap_or_default() T {
+	if res.err == nil {
+		return res.value
+	}
+	var ret T
+	return ret
+}
+
+func (res Result[T]) Unwrap_or_else(f func() T) T {
+	if res.err == nil {
+		return res.value
+	}
+	return f()
+}
+
+// UNWRAPPABLE INTERFACE
+
+// This function panic on Ok instead of Err
+func (res Result[T]) Expect_err(msg string) error {
+	if res.err != nil {
+		return res.err
+	}
+	panic(msg)
+}
+
+// This function panic on Ok instead of Err
+func (res Result[T]) Unwrap_err() error {
+	if res.err != nil {
+		return res.err
+	}
+	panic("Expect_err was called with an Ok value")
+}
+
+// transforms Result into Option, mapping Ok(v) to Some(v) and Err(e) to None
+func (res Result[T]) Ok() Optional[T] {
+	if res.err == nil {
+		return Optional[T]{value: res.value, present: true}
+	}
+	return Optional[T]{present: false}
+}
+
+// transforms Result into Option, mapping Err(e) to Some(e) and Ok(v) to None
+func (res Result[T]) Err() Optional[error] {
+	if res.err != nil {
+		return Optional[error]{value: res.err, present: true}
+	}
+	return Optional[error]{present: false}
+}

typeutils/types.go

@@ -0,0 +1,11 @@
+package typeutils
+
+type Optional[T any] struct {
+	value   T
+	present bool
+}
+
+type Result[T any] struct {
+	value T
+	err   error
+}

typeutils/utils.go

@@ -0,0 +1,27 @@
+package typeutils
+
+func Expect[T any](val Unwrappable[T], msg string) T {
+	return val.Expect(msg)
+}
+
+func Unwrap[T any](val Unwrappable[T]) T {
+	return val.Unwrap()
+}
+
+func Unwrap_or[T any](val Unwrappable[T]) (def T) {
+	return val.Unwrap_or(def)
+}
+
+func Unwrap_or_default[T any](val Unwrappable[T]) T {
+	return val.Unwrap_or_default()
+}
+
+func Unwrap_or_else[T any](val Unwrappable[T], f func() T) T {
+	return val.Unwrap_or_else(f)
+}
+
+// T cannot be inferred
+// Returns if the underlying data has a Value (false in case of None or Error)
+func Has_value(val ValueContainer) bool {
+	return val.Has_value()
+}