sqlite_numeric.rs

use sqlite::Sqlite;
use types::{self, FromSql, FromSqlRow, HasSqlType, Numeric, Float};
use std::error::Error;
use sqlite::connection::SqliteValue;
use std::str::FromStr;
use query_source::Queryable;
use row::Row;

#[derive(Debug, Clone, PartialEq, PartialOrd)]
pub enum SqliteNumeric {
    Positive {
        number: f64
    },
    Negative {
        number: f64
    },
    NaN
}

impl FromSql<types::Numeric, Sqlite> for SqliteNumeric {
    fn from_sql(bytes: Option<&SqliteValue>) -> Result<Self, Box<Error>> {
        let bytes = not_none!(bytes);
        let number = f64::from_str(bytes.read_text()).unwrap();
        if number.is_sign_positive() {
            Ok(SqliteNumeric::Positive {number: number})
        } else if number.is_sign_negative() {
            Ok(SqliteNumeric::Negative {number: number})
        } else {
            Ok(SqliteNumeric::NaN)
        }
    }
}

impl HasSqlType<Numeric> for Sqlite {
    fn metadata() -> Self::TypeMetadata {
        <Sqlite as HasSqlType<Float>>::metadata()
    }
}

impl Queryable<Numeric, Sqlite> for SqliteNumeric {
    type Row = Self;

    fn build(row: Self) -> Self {
        row
    }
}

impl FromSqlRow<Numeric, Sqlite> for SqliteNumeric {
    fn build_from_row<R:  Row<Sqlite>>(row: &mut R) -> Result<Self, Box<Error>> {
        FromSql::<Numeric, Sqlite>::from_sql(row.take())
    }
}