Regex syntax for command names

Is it possible to use regex syntax to define the name of a command, for example:
`vorpal
.command(/\d/) // accepts any digit
...`

The use case for this is to have dynamic commands that could include extra logic depending on the combination of words or digits.

A workaround could be, once the program is running through vorpal.show(); allow input without command and run them through a default action, instead of showing the error message.

Example:

`vorpal
.command([digits]) // accepts any digit instead of error message
.action((args,callback) => {
'regex processing or any other use'
...
})`

Thank you!

Start by tracing how .command() definitions are matched after vorpal.show(), including the current error path for input without a command. Define whether regex command names and a default action are both required, then verify that digit or other pattern-based input reaches the intended .action() handler without breaking ordinary commands.

Written by the indexing model from the issue text.