Implement fill_missing for all integer dtypes (#1078)

* Add cases for all int types

* Return error instead of panicking; test

* Clarify reason for panic in match

* Remove unrelate file

Whoops!

* Test all integer types

Author: billylanchantin

native/explorer/src/series.rs

@@ -508,9 +508,51 @@ pub fn s_fill_missing_with_atom(series: ExSeries, atom: &str) -> Result<ExSeries
 }
 
 #[rustler::nif(schedule = "DirtyCpu")]
-pub fn s_fill_missing_with_int(series: ExSeries, integer: i64) -> Result<ExSeries, ExplorerError> {
-    let s = series.i64()?.fill_null_with_values(integer)?.into_series();
-    Ok(ExSeries::new(s))
+pub fn s_fill_missing_with_int(
+    ex_series: ExSeries,
+    integer: i64,
+) -> Result<ExSeries, ExplorerError> {
+    let filled_series = match ex_series.dtype() {
+        DataType::Int8 => ex_series
+            .i8()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::Int16 => ex_series
+            .i16()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::Int32 => ex_series
+            .i32()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::Int64 => ex_series
+            .i64()?
+            .fill_null_with_values(integer)?
+            .into_series(),
+        DataType::UInt8 => ex_series
+            .u8()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::UInt16 => ex_series
+            .u16()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::UInt32 => ex_series
+            .u32()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        DataType::UInt64 => ex_series
+            .u64()?
+            .fill_null_with_values(integer.try_into()?)?
+            .into_series(),
+        // We shouldn't ever call `Native.s_fill_missing_with_int/2` from the
+        // Elixir side with a non-integer series.
+        other => {
+            panic!("s_fill_missing_with_int/2 implemented for integer types, found: {other:?}")
+        }
+    };
+
+    Ok(ExSeries::new(filled_series))
 }
 
 #[rustler::nif(schedule = "DirtyCpu")]

test/explorer/series_test.exs

@@ -608,8 +608,10 @@ defmodule Explorer.SeriesTest do
     end
 
     test "with integer" do
-      s1 = Series.from_list([1, 2, nil, 4])
-      assert Series.fill_missing(s1, 3) |> Series.to_list() == [1, 2, 3, 4]
+      for integer_dtype <- Explorer.Shared.integer_types() do
+        series = Series.from_list([1, 2, nil, 4], dtype: integer_dtype)
+        assert Series.fill_missing(series, 3) |> Series.to_list() == [1, 2, 3, 4]
+      end
     end
 
     test "with float" do
@@ -856,6 +858,14 @@ defmodule Explorer.SeriesTest do
                    "fill_missing with :neg_infinity values require a float series, got {:s, 64}",
                    fn -> Series.fill_missing(s1, :neg_infinity) end
     end
+
+    test "with integer beyond accepted precision" do
+      s1 = Series.from_list([1, 2, nil, 4], dtype: :s8)
+
+      assert_raise RuntimeError,
+                   "out of range integral type conversion attempted",
+                   fn -> Series.fill_missing(s1, 1_000) end
+    end
   end
 
   describe "equal/2" do