NewShell creates a REPL from a runnable and a command store.

NewText creates a Command with sane defaults.

Disguard is used as a High Order Function to disguard error messages.

ErrShowHelp is a sentinel error message for showing help.

Nothing is used as a High Order Function to consume all group event runs into nothing.

CommandContext is the context the command was run with.

Shell defines a REPL that can be interactively accessed.

Text defines a simple text based command, that can be useful for creating commands that require more text based explanations.

Runnable allows the shell to interact with a given runnable type.

Store holds the command prefixes to able to walk over.