5.3 Prefix Classes

Currently the transient-prefix class is being used for all prefix commands and there is only a single generic function that can be specialized based on the class of a prefix command.

Function: transient--history-init obj

This generic function is called while setting up the transient and is responsible for initializing the history slot. This is the transient-wide history; many individual infixes also have a history of their own.

The default (and currently only) method extracts the value from the global variable transient-history.

A transient prefix command’s object is stored in the transient--prefix property of the command symbol. While a transient is active, a clone of that object is stored in the variable transient--prefix. A clone is used because some changes that are made to the active transient’s object should not affect later invocations.