Module maybe

Optional values.

Remarks

Maybe<T> is a type that represents an optional value. It is represented by two variants: Nothing and Just<T>.

• Nothing is the absent Maybe and contains no value.
• A Just<T> is a present Maybe and contains a value of type T.

The companion Maybe:namespace namespace provides utilities for working with the Maybe<T> type.

Common uses for Maybe include:

• Initial values
• Nullable values
• Return values for functions that are not defined over their entire input range (partial functions)
• Return values for reporting simple failures, where Nothing is returned on failure

Using Maybe with promises

AsyncMaybe<T> is an alias for Promise<Maybe<T>>. The companion AsyncMaybe:namespace namespace provides utilities for working with the AsyncMaybe<T> type.

To accommodate promise-like values, this module also provides the AsyncMaybeLike<T> type as an alias for PromiseLike<Maybe<T>>.

Importing from this module

The types and namespaces from this module can be imported under the same aliases:

import { AsyncMaybe, Maybe } from "@neotype/prelude/maybe.js";
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Or, they can be imported and aliased separately:

import {
    type AsyncMaybe,
    type Maybe,
    AsyncMaybe as AM,
    Maybe as M
} from "@neotype/prelude/maybe.js";
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