Std.Option.fold

fn

This is a callable function.

What it does

The result of transforming the value, or a fallback when there is none.

The arguments are in the order a reader meets them: the value, what to do

with it, and what to do without it.

Read the signature

• The text after the name is the type checked by Pudu.
• Read arrows from left to right: inputs come first, and the final type is returned.
• Names inside [ ] are type arguments, such as the item type held by a collection.
• Option holds Some(value) or None when no value is available.