You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: metacmd.go
    path of file: ./repos/usql/metacmd
    
    the code of the file until where you have to start completion: // Package metacmd contains meta information and implentation for usql's
// backslash (\) commands.
package metacmd

import (
	"github.com/xo/usql/stmt"
	"github.com/xo/usql/text"
)

// Metacmd represents a command and associated meta inf
    
func Decode(name string, params *stmt.Params) (Runner, error) {
	mc, ok := cmdMap[name]
	if !ok || name == "" {
		return nil, text.ErrUnknownCommand
	}
	cmd := cmds[mc]
	return RunnerFunc(func(h Handler) (Option, error) {
		p := &Params{
			Handler: h,
			Name:    name,
			Params:  params,
		}
		err := cmd.Process(p)
		return p.Option, err
	}), nil
}