polars_core/utils/
any_value.rs

1use crate::prelude::*;
2use crate::utils::dtypes_to_supertype;
3
4/// Determine the supertype of a collection of [`AnyValue`].
5///
6/// [`AnyValue`]: crate::datatypes::AnyValue
7pub fn any_values_to_supertype<'a, I>(values: I) -> PolarsResult<DataType>
8where
9    I: IntoIterator<Item = &'a AnyValue<'a>>,
10{
11    let dtypes = any_values_to_dtype_set(values);
12    dtypes_to_supertype(&dtypes)
13}
14
15/// Determine the supertype and the number of unique data types of a collection of [`AnyValue`].
16///
17/// [`AnyValue`]: crate::datatypes::AnyValue
18pub fn any_values_to_supertype_and_n_dtypes<'a, I>(values: I) -> PolarsResult<(DataType, usize)>
19where
20    I: IntoIterator<Item = &'a AnyValue<'a>>,
21{
22    let dtypes = any_values_to_dtype_set(values);
23    let supertype = dtypes_to_supertype(&dtypes)?;
24    let n_dtypes = dtypes.len();
25    Ok((supertype, n_dtypes))
26}
27
28/// Extract the ordered set of data types from a collection of AnyValues
29///
30/// Retaining the order is important if the set is used to determine a supertype,
31/// as this can influence how Struct fields are constructed.
32fn any_values_to_dtype_set<'a, I>(values: I) -> PlIndexSet<DataType>
33where
34    I: IntoIterator<Item = &'a AnyValue<'a>>,
35{
36    values.into_iter().map(|av| av.into()).collect()
37}