code: func ScalarFuncs2Exprs(funcs []*ScalarFunction) []Expression {
  	result := make([]Expression, 0, len(funcs))
  	for _, col := range funcs {
  		result = append(result, col)
  	}
  	return result
  }
docs: // ScalarFuncs2Exprs converts []*ScalarFunction to []Expression.