Line data    Source code

       1              : use crate::to_statement::private::{Sealed, ToStatementType};
       2              : use crate::Statement;
       3              : 
       4              : mod private {
       5              :     use crate::{Client, Error, Statement};
       6              : 
       7              :     pub trait Sealed {}
       8              : 
       9              :     pub enum ToStatementType<'a> {
      10              :         Statement(&'a Statement),
      11              :         Query(&'a str),
      12              :     }
      13              : 
      14              :     impl ToStatementType<'_> {
      15            0 :         pub async fn into_statement(self, client: &Client) -> Result<Statement, Error> {
      16            0 :             match self {
      17            0 :                 ToStatementType::Statement(s) => Ok(s.clone()),
      18            0 :                 ToStatementType::Query(s) => client.prepare(s).await,
      19              :             }
      20            0 :         }
      21              :     }
      22              : }
      23              : 
      24              : /// A trait abstracting over prepared and unprepared statements.
      25              : ///
      26              : /// Many methods are generic over this bound, so that they support both a raw query string as well as a statement which
      27              : /// was prepared previously.
      28              : ///
      29              : /// This trait is "sealed" and cannot be implemented by anything outside this crate.
      30              : pub trait ToStatement: Sealed {
      31              :     #[doc(hidden)]
      32              :     fn __convert(&self) -> ToStatementType<'_>;
      33              : }
      34              : 
      35              : impl ToStatement for Statement {
      36            0 :     fn __convert(&self) -> ToStatementType<'_> {
      37            0 :         ToStatementType::Statement(self)
      38            0 :     }
      39              : }
      40              : 
      41              : impl Sealed for Statement {}
      42              : 
      43              : impl ToStatement for str {
      44            0 :     fn __convert(&self) -> ToStatementType<'_> {
      45            0 :         ToStatementType::Query(self)
      46            0 :     }
      47              : }
      48              : 
      49              : impl Sealed for str {}
      50              : 
      51              : impl ToStatement for String {
      52            0 :     fn __convert(&self) -> ToStatementType<'_> {
      53            0 :         ToStatementType::Query(self)
      54            0 :     }
      55              : }
      56              : 
      57              : impl Sealed for String {}