Unify column accessor API around col/colGroup and deprecate constructor aliases

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/constructors.kt

@@ -44,8 +44,10 @@ import kotlin.reflect.typeOf
 
 public fun <T> column(): ColumnDelegate<T> = ColumnDelegate()
 
+@Deprecated("Use col(name) instead.", ReplaceWith("col<T>(name)"))
 public fun <T> column(name: String): ColumnAccessor<T> = ColumnAccessorImpl(name)
 
+@Deprecated("Use col(path) instead.", ReplaceWith("col<T>(path)"))
 public fun <T> column(path: ColumnPath): ColumnAccessor<T> = ColumnAccessorImpl(path)
 
 @Deprecated(DEPRECATED_ACCESS_API)
@@ -54,8 +56,10 @@ public fun <T> column(property: KProperty<T>): ColumnAccessor<T> = ColumnAccesso
 
 public fun <T> ColumnGroupReference.column(): ColumnDelegate<T> = ColumnDelegate(this)
 
+@Deprecated("Use col(name) instead.", ReplaceWith("this.col<T>(name)"))
 public fun <T> ColumnGroupReference.column(name: String): ColumnAccessor<T> = ColumnAccessorImpl(path() + name)
 
+@Deprecated("Use col(path) instead.", ReplaceWith("this.col<T>(path)"))
 public fun <T> ColumnGroupReference.column(path: ColumnPath): ColumnAccessor<T> = ColumnAccessorImpl(this.path() + path)
 
 @Deprecated(DEPRECATED_ACCESS_API)
@@ -131,14 +135,18 @@ public fun columnGroup(): ColumnDelegate<DataRow<*>> = column()
 @JvmName("columnGroupTyped")
 public fun <T> columnGroup(): ColumnDelegate<DataRow<T>> = column()
 
+@Deprecated("Use colGroup(name) instead.", ReplaceWith("colGroup(name)"))
 public fun columnGroup(name: String): ColumnAccessor<DataRow<*>> = column(name)
 
 @JvmName("columnGroupTyped")
+@Deprecated("Use colGroup(name) instead.", ReplaceWith("colGroup<T>(name)"))
 public fun <T> columnGroup(name: String): ColumnAccessor<DataRow<T>> = column(name)
 
+@Deprecated("Use colGroup(path) instead.", ReplaceWith("colGroup(path)"))
 public fun columnGroup(path: ColumnPath): ColumnAccessor<DataRow<*>> = column(path)
 
 @JvmName("columnGroupTyped")
+@Deprecated("Use colGroup(path) instead.", ReplaceWith("colGroup<T>(path)"))
 public fun <T> columnGroup(path: ColumnPath): ColumnAccessor<DataRow<T>> = column(path)
 
 @JvmName("columnGroupDataRowKProperty")
@@ -155,17 +163,21 @@ public fun ColumnGroupReference.columnGroup(): ColumnDelegate<DataRow<*>> = Colu
 @JvmName("columnGroupTyped")
 public fun <T> ColumnGroupReference.columnGroup(): ColumnDelegate<DataRow<T>> = ColumnDelegate(this)
 
+@Deprecated("Use colGroup(name) instead.", ReplaceWith("this.colGroup(name)"))
 public fun ColumnGroupReference.columnGroup(name: String): ColumnAccessor<DataRow<*>> =
     ColumnAccessorImpl(path() + name)
 
 @JvmName("columnGroupTyped")
+@Deprecated("Use colGroup(name) instead.", ReplaceWith("this.colGroup<T>(name)"))
 public fun <T> ColumnGroupReference.columnGroup(name: String): ColumnAccessor<DataRow<T>> =
     ColumnAccessorImpl(path() + name)
 
+@Deprecated("Use colGroup(path) instead.", ReplaceWith("this.colGroup(path)"))
 public fun ColumnGroupReference.columnGroup(path: ColumnPath): ColumnAccessor<DataRow<*>> =
     ColumnAccessorImpl(this.path() + path)
 
 @JvmName("columnGroupTyped")
+@Deprecated("Use colGroup(path) instead.", ReplaceWith("this.colGroup<T>(path)"))
 public fun <T> ColumnGroupReference.columnGroup(path: ColumnPath): ColumnAccessor<DataRow<T>> =
     ColumnAccessorImpl(this.path() + path)
 

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

@@ -51,6 +51,21 @@ class ColTests : ColumnsSelectionDslTests() {
         ).shouldAllBeEqual()
     }
 
+    @Test
+    @Suppress("DEPRECATION")
+    fun `column constructors are aliases of col`() {
+        listOf(
+            df.select { col("age") },
+            df.select { column<Any?>("age") },
+            df.select { col<Int>("age") },
+            df.select { column<Int>("age") },
+            df.select { col(pathOf("age")) },
+            df.select { column<Any?>(pathOf("age")) },
+            df.select { col<Int>(pathOf("age")) },
+            df.select { column<Int>(pathOf("age")) },
+        ).shouldAllBeEqual()
+    }
+
     @Test
     fun `col at lower level`() {
         val firstNameAccessor = column<String>("firstName")

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

@@ -44,6 +44,21 @@ class ColGroupTests : ColumnsSelectionDslTests() {
         ).shouldAllBeEqual()
     }
 
+    @Test
+    @Suppress("DEPRECATION")
+    fun `columnGroup constructors are aliases of colGroup`() {
+        listOf(
+            dfGroup.select { colGroup("name") },
+            dfGroup.select { columnGroup("name") },
+            dfGroup.select { colGroup<Name2>("name") },
+            dfGroup.select { columnGroup<Name2>("name") },
+            dfGroup.select { colGroup(pathOf("name")) },
+            dfGroup.select { columnGroup(pathOf("name")) },
+            dfGroup.select { colGroup<Name2>(pathOf("name")) },
+            dfGroup.select { columnGroup<Name2>(pathOf("name")) },
+        ).shouldAllBeEqual()
+    }
+
     @Test
     fun `frameCol at lower level`() {
         val firstNamesAccessor = columnGroup<FirstNames>("firstName")

docs/StardustDocs/topics/concepts/StringApi.md

@@ -41,6 +41,8 @@ via *`String` column accessors*.
 or with any other [CS DSL methods](ColumnSelectors.md#functions-overview).
 
 String column accessors are created using special functions.
+Use `col(...)` and `colGroup(...)` as the canonical accessor constructors.
+Legacy `column(...)` and `columnGroup(...)` constructor aliases are kept for backward compatibility.
 In the Columns Selection DSL, they have the special type `ColumnAccessor`,
 while in row expressions they resolve to concrete value types.