The documentation for Association offers the following tantalizing (and frustrating) remarks...

Typical list operations (such as Map, Select, and Sort) apply to the values in an association, leaving the keys unchanged.

... and ...

Keys are "transparent" for many operations

... but it remains silent on the identity of those "many operations" beyond a few examples.

My impression is that the consequences of this transparency are still being worked out. Membership in the set of "many operations" seems to be arbitrary at the moment, causing some surprising behaviour (example). My hope is that a principle will emerge that will allow us to make an a priori determination as to whether a given piece of functionality is one of the "many operations", without having to experiment.

The documentation for Association offers the following tantalizing (and frustrating) remarks...

Typical list operations (such as Map, Select, and Sort) apply to the values in an association, leaving the keys unchanged.

... and ...

Keys are "transparent" for many operations

... but it remains silent on the identity of those "many operations" beyond a few examples.

My impression is that the consequences of this transparency are still being worked out. Membership in the set of "many operations" seems to be arbitrary at the moment, causing some surprising behaviour (example). My hope is that a principle will emerge that will allow us to make an a priori determination as to whether a given piece of functionality is one of the "many operations", without having to experiment.