init research

dataframe/plugins/kotlin-dataframe/testData/box/dropNulls.kt

@@ -0,0 +1,15 @@
+import org.jetbrains.kotlinx.dataframe.*
+import org.jetbrains.kotlinx.dataframe.annotations.*
+import org.jetbrains.kotlinx.dataframe.api.*
+import org.jetbrains.kotlinx.dataframe.io.*
+
+data class Nested(val i: Double?)
+
+data class Record(val a: String?, val b: Int?, val nested: Nested)
+
+fun box(): String {
+    val df = listOf(Record("112", 42, Nested(3.0))).toDataFrame(maxDepth = 1)
+    df.dropNulls { a and b }
+
+    return "OK"
+}