Method single_value

datafusion/expr-common/src/interval_arithmetic.rs:2239–2251

If the interval has collapsed to a single value, return that value. Otherwise, returns `None`. # Examples ``` use datafusion_common::ScalarValue; use datafusion_expr_common::interval_arithmetic::Interval; use datafusion_expr_common::interval_arithmetic::NullableInterval; let interval = NullableInterval::from(ScalarValue::Int32(Some(4))); assert_eq!(interval.single_value(), Some(ScalarValue::Int

(&self)

    /// assert_eq!(interval.single_value(), None);
    /// ```
    pub fn single_value(&self) -> Option<ScalarValue> {
        match self {
            Self::Null { datatype } => {
                Some(ScalarValue::try_from(datatype).unwrap_or(ScalarValue::Null))
            }
            Self::MaybeNull { values } | Self::NotNull { values }
                if values.lower == values.upper && !values.lower.is_null() =>
            {
                Some(values.lower.clone())
            }
            _ => None,
        }
    }
}

#[cfg(test)]