Fix compilation for series

Author: chitralverma

core/src/main/scala/org/polars/scala/polars/api/JSeries.java

@@ -0,0 +1,69 @@
+package org.polars.scala.polars.api;
+
+import scala.Boolean;
+import scala.Int;
+import scala.jdk.javaapi.CollectionConverters;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+class JSeries {
+    final static String EmptyString = "";
+
+    static Series ofList(String name, Iterable<Iterable> values) {
+        Iterator<Iterable> valuesIter = values.iterator();
+        List<Series> sList = new ArrayList<>();
+
+        while (valuesIter.hasNext()) {
+            Iterable subList = valuesIter.next();
+            Object head = subList.iterator().next();
+
+            Series thisSeries;
+            if (head instanceof Integer || head instanceof Int) {
+                thisSeries = Series.ofInt(EmptyString, subList);
+            } else if (head instanceof Long) {
+                thisSeries = Series.ofLong(EmptyString, subList);
+            } else if (head instanceof Float) {
+                thisSeries = Series.ofFloat(EmptyString, subList);
+            } else if (head instanceof Double) {
+                thisSeries = Series.ofDouble(EmptyString, subList);
+            } else if (head instanceof Boolean) {
+                thisSeries = Series.ofBoolean(EmptyString, subList);
+            } else if (head instanceof LocalDate) {
+                thisSeries = Series.ofDate(EmptyString, subList);
+            } else if (head instanceof LocalDateTime) {
+                thisSeries = Series.ofDateTime(EmptyString, subList);
+            } else if (head instanceof String) {
+                thisSeries = Series.ofString(EmptyString, subList);
+            } else if (head instanceof java.lang.Iterable) {
+                thisSeries = ofList(EmptyString, subList);
+            } else if (head instanceof scala.collection.Iterable) {
+                Iterable<Iterable> s = (Iterable<Iterable>) StreamSupport.stream(subList.spliterator(), false)
+                        .map(v -> CollectionConverters.asJava((scala.collection.Iterable) v))
+                        .collect(Collectors.toList());
+
+                thisSeries = ofList(EmptyString, s);
+            } else if (head.getClass().isArray()) {
+                Iterable<Iterable> s = (Iterable<Iterable>) StreamSupport.stream(subList.spliterator(), false)
+                        .map(v -> Arrays.asList((Object[]) v))
+                        .collect(Collectors.toList());
+
+                thisSeries = ofList(EmptyString, s);
+            } else {
+                throw new IllegalArgumentException(
+                        String.format("Nested series of provided internal type `%s` is currently not supported.", head.getClass().getSimpleName())
+                );
+            }
+
+            sList.add(thisSeries);
+        }
+
+        return Series.ofSeries(name, sList);
+    }
+}