code: func ExpsToString(exps []Expression) string {
  	if exps != nil {
  		if len(exps) == 1 {
  			return exps[0].String()
  		}
  
  		var buffer bytes.Buffer
  		for _, exp := range exps {
  			buffer.WriteString(exp.String())
  		}
  
  		return buffer.String()
  	}
  	return ""
  }
docs: // ExpsToString joins (without separator) individual expression string representations.