function command( repl ) {
	return onCommand;

	/**
	* Deletes a workspace.
	*
	* @private
	* @param {string} [name] - workspace name
	* @returns {void}
	*/
	function onCommand( name ) {
		var err;
		var ws;
		if ( arguments.length ) {
			if ( !isString( name ) ) {
				err = new TypeError( format( 'invalid argument. Must provide a string. Value: `%s`.', name ) );
				debug( 'Error: %s', err.message );
				repl._ostream.write( 'Error: '+err.message+'\n' );
				return;
			}
			if ( !hasOwnProp( repl._workspaces, name ) ) {
				err = new Error( format( 'invalid argument. Unrecognized workspace name. Value: `%s`.', name ) );
				debug( 'Error: %s', err.message );
				repl._ostream.write( 'Error: '+err.message+'\n' );
				return;
			}
			ws = name;
		} else {
			ws = repl._currentWorkspace;
		}
		if ( ws === 'base' ) {
			err = new Error( 'invalid operation. Cannot delete the `base` workspace.' );
			debug( 'Error: %s', err.message );
			repl._ostream.write( 'Error: '+err.message+'\n' );
			return;
		}
		if ( ws === repl._currentWorkspace ) {
			repl._context.workspace( 'base' );
		}
		delete repl._workspaces[ ws ];
		log( repl, 'Deleted \''+ws+'\' workspace.' );
		debug( 'Deleted \'%s\' workspace.', ws );
	}
}
Returns a callback to be invoked upon calling the `deleteWorkspace` command.

@private
@param {REPL} repl - REPL instance
@returns {Function} callback