regexp.go
func Substitute(r, replacement string) Filter {
	return FilterFunc(func(arg Arg) error {
		re, err := regexp.Compile(r)
		if err != nil {
			return err
		}
		for s := range arg.In {
			arg.Out <- re.ReplaceAllString(s, replacement)
		}
		return nil
	})
}
func Substitute(r, replacement string) Filter {
	return FilterFunc(func(arg Arg) error {
		re, err := regexp.Compile(r)
		if err != nil {
			return err
		}
		for s := range arg.In {
			arg.Out <- re.ReplaceAllString(s, replacement)
		}
		return nil
	})
}
func Substitute ( r , replacement string ) Filter { return FilterFunc ( func ( arg Arg ) error { re , err := regexp . Compile ( r ) if err != nil { return err } for s := range arg . In { arg . Out <- re . ReplaceAllString ( s , replacement ) } return nil } ) }
// Substitute replaces all occurrences of the regular expression r in
// an input item with replacement.  The replacement string can contain
// $1, $2, etc. which represent submatches of r.
Substitute replaces all occurrences of the regular expression r in an input item with replacement . The replacement string can contain $1 $2 etc . which represent submatches of r .