Std.Map.mapKeys

fn

This is a callable function.

What it does

Every key transformed. A transformation that sends two keys to one keeps the

entry that comes later in key order, which is the same rule insertion uses.

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.
• & borrows a value for this call instead of moving or copying it.
• Names inside [ ] are type arguments, such as the item type held by a collection.