code: func Strings(dst io.Writer, from, to string, options ...Option) error {
  	var p *schemalex.Parser
  	for _, o := range options {
  		switch o.Name() {
  		case optkeyParser:
  			p = o.Value().(*schemalex.Parser)
  		}
  	}
  	if p == nil {
  		p = schemalex.New()
  	}
  
  	stmts1, err := p.ParseString(from)
  	if err != nil {
  		return errors.Wrapf(err, `failed to parse "from" %s`, from)
  	}
  
  	stmts2, err := p.ParseString(to)
  	if err != nil {
  		return errors.Wrapf(err, `failed to parse "to" %s`, to)
  	}
  
  	return Statements(dst, stmts1, stmts2, options...)
  }
docs: // Strings compares two strings and generates a series
  // of statements to migrate from the old one to the new one,
  // writing the result to `dst`