Inline column/columnOf usages in split.md

Author: koperagen

core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/samples/api/Modify.kt

@@ -536,9 +536,7 @@ class Modify : TestBase() {
     @TransformDataFrameExpressions
     fun splitRegex1() {
         // SampleStart
-        val name by column<String>()
-
-        merged.split { name }
+        merged.split { "name"<String>() }
             .match("""(.*) \((.*)\)""")
             .inward("firstName", "lastName")
         // SampleEnd
@@ -557,11 +555,12 @@ class Modify : TestBase() {
             7, 8,
             9, 10,
         )
-        val group by columnOf(df1, df2)
-        val id by columnOf("x", "y")
-        val df = dataFrameOf(id, group)
+        val df = dataFrameOf(
+            "id" to columnOf("x", "y"),
+            "group" to columnOf(df1, df2)
+        )
 
-        df.split { group }.intoColumns()
+        df.split { "group"<AnyFrame>() }.intoColumns()
         // SampleEnd
     }
 

docs/StardustDocs/topics/split.md

@@ -112,9 +112,7 @@ df.split { "name"["lastName"]<String>() }
 <!---FUN splitRegex1-->
 
 ```kotlin
-val name by column<String>()
-
-merged.split { name }
+merged.split { "name"<String>() }
     .match("""(.*) \((.*)\)""")
     .inward("firstName", "lastName")
 ```
@@ -136,11 +134,12 @@ val df2 = dataFrameOf("a", "b")(
     7, 8,
     9, 10,
 )
-val group by columnOf(df1, df2)
-val id by columnOf("x", "y")
-val df = dataFrameOf(id, group)
+val df = dataFrameOf(
+    "id" to columnOf("x", "y"),
+    "group" to columnOf(df1, df2)
+)
 
-df.split { group }.intoColumns()
+df.split { "group"<AnyFrame>() }.intoColumns()
 ```
 
 <!---END-->