Reserve [p]cancel

[zephyrkul]

Feature request

Select the type of feature you are requesting:

• Cog
• Command
• API functionality

Describe your requested feature

Reserve a no-op [p]cancel command, which is currently used by the built-in cancelled predicate, in the core cog, with a valid docstring, in order to prevent surprising behavior from other third-party cogs registering that command.

[mikeshardmind]

Rather than reserving a command here, it might be better to forbid the use of a list of strings as command names or alises and raise an error explaining this when someone attempts to create a command named as such.

This prevents us from dispatching on a no-op while still preventing the surprising behaviors.