Simple and fast way to access interactive functions associated with a package

[uzibalqa]

I am using M-x protoc to show me the interactive functions provided by the 
package protoc. Is it possible

to have a shortcut for displaying protoc related functions without having to 
write protoc TAB after calling M-x?

For instance, the following fails

(global-set-key (kbd "H-x") (kbd "M-x protoc"))

As I understand, there exists no association between functions (or variables) 
and the packages they were defined in,

nor are packages even first–class objects. There is just the global environment 
and whatever functions (and variables)

that have been defined therein.

By convention one names the functions and variables defined in a package with a 
prefix that contains or is at least

similar to the package name. Perhaps one could manage the list of known symbols 
using mapatoms, searching for

those that are fboundp and have the prefix one are looking for.

But I do not know how an actual implementation could look like. Or whether it 
is a good plan.