README
¶
go-nul
Package nul implements a nullable optional-type, for the Go programming language.
In other programming languages, an optional-type might be known as: a option-type, or a maybe-type.
Documention
Online documentation, which includes examples, can be found at: http://godoc.org/github.com/reiver/go-nul
Examples
Here is an example nullable optional-type that can hold a string:
import "github.com/reiver/go-nul"
//
var op nul.Nullable[string] // the default value is nothing.
// ...
if nul.Nothing[string]() == op {
fmt.Println("nothing")
}
// ...
op = nul.Null[string]()
// ...
if nul.Null[string]() == op {
fmt.Println("null")
}
// ...
op = nul.Something("Hello world! 👾")
// ...
switch op {
case op.Nothing[string]():
//@TODO
case op.Null[string]():
//@TODO
case op.Something("apple"):
//@TODO
case op.Something("banana"):
//@TODO
case op.Something("cherry"):
//@TODO
default:
//@TODO
}
// ...
value, found := op.Get()
if found {
fmt.Println("VALUE:", value)
} else {
fmt.Println("either nothing or null")
}
Import
To import package nul use import code like the follownig:
import "github.com/reiver/go-nul"
Installation
To install package nul do the following:
GOPROXY=direct go get github.com/reiver/go-nul
Author
Package nul was written by Charles Iliya Krempeaux
Documentation
¶
Index ¶
- type Nullable
- func (receiver Nullable[T]) Filter(fn func(T) bool) Nullable[T]
- func (receiver Nullable[T]) Get() (T, bool)
- func (receiver Nullable[T]) GetElse(alternative T) T
- func (receiver Nullable[T]) GoString() string
- func (receiver Nullable[T]) IsNothing() bool
- func (receiver Nullable[T]) IsNull() bool
- func (receiver Nullable[T]) MarshalJSON() ([]byte, error)
- func (receiver Nullable[T]) Optional() opt.Optional[T]
- func (receiver *Nullable[T]) UnmarshalJSON(data []byte) error
- func (receiver Nullable[T]) WhenNothing(fn func())
- func (receiver Nullable[T]) WhenNull(fn func())
- func (receiver Nullable[T]) WhenSomething(fn func(T))
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Nullable ¶
type Nullable[T any] struct { // contains filtered or unexported fields }
func (Nullable[T]) Get ¶
Get returns the value inside of the nullable-optional-type if it is holding something.
Example usage:
var nl nul.Nullable[string]
// ...
value, found := nl.Get()
if found {
fmt.Println("VALUE:", value)
} else {
fmt.Println("nothing")
}
func (Nullable[T]) GetElse ¶
func (receiver Nullable[T]) GetElse(alternative T) T
GetElse returns the value inside of the nullable-optional-type if it is holding something. Else it returns the alternstive value passed as a parameter. Example usage:
var nl nul.Nullable[string]
// ...
value := nl.GetElse(alternative)
fmt.Println("VALUE:", value)
func (Nullable[T]) MarshalJSON ¶
MarshalJSON makes it so json.Marshaler is implemented.
func (*Nullable[T]) UnmarshalJSON ¶
UnmarshalJSON makes it so json.Unmarshaler is implemented.
func (Nullable[T]) WhenNothing ¶
func (receiver Nullable[T]) WhenNothing(fn func())
func (Nullable[T]) WhenSomething ¶
func (receiver Nullable[T]) WhenSomething(fn func(T))
Source Files