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vortex_array/expr/stats/
provider.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use vortex_error::VortexError;
5use vortex_error::vortex_panic;
6
7use super::StatType;
8use crate::expr::stats::Precision;
9use crate::expr::stats::Stat;
10use crate::scalar::Scalar;
11
12pub trait StatsProvider {
13    fn get(&self, stat: Stat) -> Precision<Scalar>;
14
15    /// Count of stored stats with known values.
16    fn len(&self) -> usize;
17
18    /// Predicate equivalent to a [len][Self::len] of zero.
19    fn is_empty(&self) -> bool {
20        self.len() == 0
21    }
22}
23
24impl<S> StatsProviderExt for S where S: StatsProvider {}
25
26pub trait StatsProviderExt: StatsProvider {
27    fn get_scalar_bound<S: StatType<Scalar>>(&self) -> Option<S::Bound> {
28        self.get(S::STAT).bound::<S>()
29    }
30
31    fn get_as<T: for<'a> TryFrom<&'a Scalar, Error = VortexError>>(
32        &self,
33        stat: Stat,
34    ) -> Precision<T> {
35        self.get(stat).map(|v| {
36            T::try_from(&v).unwrap_or_else(|err| {
37                vortex_panic!(
38                    err,
39                    "Failed to get stat {} as {}",
40                    stat,
41                    std::any::type_name::<T>()
42                )
43            })
44        })
45    }
46
47    fn get_as_bound<S, U>(&self) -> Option<S::Bound>
48    where
49        S: StatType<U>,
50        U: for<'a> TryFrom<&'a Scalar, Error = VortexError>,
51    {
52        self.get_as::<U>(S::STAT).bound::<S>()
53    }
54}