Simpler.NetCore

Extension methods

.IfNotNull(Action)

A fluent alternative to if (obj != null) { /* process object */ }. Mainly useful when modifying/assigning properties.

IList<Boolean>? n = null;
IList<Boolean>? s = new List<Boolean>();

n.IfNotNull(l => l!.Add(true)); // Returns `false`, `n` remains `null`
s.IfNotNull(l => l!.Add(true)); // Returns `true`, `s` now contains one boolean element: `true`

.IfNotNull(func) (nullable)

A fluent alternative to value != null ? func(value) : null;.

null.IfNotNull(_ => _ + _);    // null
"Text".IfNotNull(_ => _ + _);  // "TextText"

.IfNotNull(func, fallback)

A fluent alternative to value != null ? func(value) : fallback;.

null.IfNotNull(_ => _ + _, "Nothing");    // "Nothing"
"Text".IfNotNull(_ => _ + _, "Nothing");  // "TextText"

.ToStringOr()

A fluent alternative to value?.ToString() ?? fallback;.

null.ToStringOr("Nothing");   // "Nothing"
123.ToStringOr("Nothing");    // "123"

.ToStringOrEmpty()

A fluent alternative to value?.ToString() ?? String.Empty;.

null.ToStringOrEmpty();   // ""
321.ToStringOrEmpty();    // "321"

.ToMaybe()

Create a Maybe<T> (see below) from a given object/value. A fluent alternative to May.Be(obj).

null.Maybe().IsEmpty;   // true
"Text".Maybe().IsEmpty; // false

Maybe

A thin wrapper turning a nullable value into a single-element collection. This allows to operate with null/non-null values as with empty/non-empty collection.

.Get(), .GetOr(..)

Retrieve the value of the Maybe, throwing an exception or providing a fallback value if the Maybe doesn't have a value.

var yes = May.Be("yes");
var no = May.Be<String>(null);

yes.Any(); // true
no.Any();  // false

yes.Get(); // "yes"
no.Get();  // NullReferenceException

no.GetOr("full");  // "full"
no.GetOr("empty"); // "empty"

var values = new[] { "a", "b", "c" };
var yes = May.Be("X");
var no = May.Be((String)null!);
String.Join("", yes.Concat(no).Concat(values)); // "Xabc"

.Set(), .SetIfEmpty()

May.BeNot<Int32>().Set(1);              // Maybe<Int32>(1)
May.BeNot<String>().SetIfEmpty("full"); // Maybe<String>("full")

.Map()

Run a function on the value of Maybe if present.

var yes = May.Be("yes");
var no = May.BeNot<String>();
yes.Map(_ => true) // Maybe<Boolean>(true)
no.Map(_ => 1)     // Maybe<Int32>(null)

.MapGetOr()

Map (transform) the value of this Maybe if it has one, or to a fallback value if not.

May.Be(null).MapGetOr(_ => _ + _, "Nothing");   // "Nothing"
May.Be("Yes").MapGetOr(_ => _ + _, "Nothing");  // "YesYes"