Issue-235: Fix Documentation not showing up on the website

core/src/main/scala/doric/sem/JoinOps.scala

@@ -5,7 +5,7 @@ import doric.{DoricColumn, DoricJoinColumn}
 
 import org.apache.spark.sql.{DataFrame, Dataset}
 
-private[sem] trait JoinOps {
+protected trait JoinOps {
   implicit class DataframeJoinSyntax[A](df: Dataset[A]) {
 
     /**

core/src/main/scala/doric/syntax/AggregationColumns.scala

@@ -8,7 +8,7 @@ import doric.Doric
 import org.apache.spark.sql.{Column, functions => f}
 import org.apache.spark.sql.catalyst.expressions.aggregate.Sum
 
-private[syntax] trait AggregationColumns {
+protected trait AggregationColumns {
 
   /**
     * Aggregate function: returns the sum of all values in the expression.

core/src/main/scala/doric/syntax/ArrayColumns.scala

@@ -33,7 +33,7 @@ protected final case class Zipper[T1, T2, F[_]: CollectionType](
   }
 }
 
-private[syntax] trait ArrayColumns {
+protected trait ArrayColumns {
 
   /**
     * Concatenates multiple array columns together into a single column.
@@ -460,7 +460,8 @@ private[syntax] trait ArrayColumns {
       * }}}
       *
       * @group Array Type
-      * @see [[org.apache.spark.sql.functions.exists]]
+      * @see org.apache.spark.sql.functions.exists
+      * @todo scaladoc link not available for spark 2.4
       */
     def exists(fun: DoricColumn[T] => BooleanColumn): BooleanColumn = {
       val xv = x(col.getIndex(0))
@@ -580,7 +581,8 @@ private[syntax] trait ArrayColumns {
       * @note
       * if `start` == 0 an exception will be thrown
       * @group Array Type
-      * @see [[org.apache.spark.sql.functions.slice(x:org\.apache\.spark\.sql\.Column,start:org\.apache\.spark\.sql\.Column,length* org.apache.spark.sql.functions.slice]]
+      * @see org.apache.spark.sql.functions.slice
+      * @todo scaladoc link (issue #135)
       */
     def slice(start: IntegerColumn, length: IntegerColumn): DoricColumn[F[T]] =
       (col.elem, start.elem, length.elem)
@@ -606,12 +608,14 @@ private[syntax] trait ArrayColumns {
       * Merge two given arrays, element-wise, into a single array using a function.
       * If one array is shorter, nulls are appended at the end to match the length of the longer
       * array, before applying the function.
+      *
       * @example {{{
       *   df.select(colArray("val1").zipWith(col("val2"), concat(_, _)))
       * }}}
       *
       * @group Array Type
-      * @see [[org.apache.spark.sql.functions.zip_with]]
+      * @see org.apache.spark.sql.functions.zip_with
+      * @todo scaladoc link not available for spark 2.4
       */
     def zipWith[T2](
         col2: DoricColumn[F[T2]]
@@ -638,8 +642,8 @@ private[syntax] trait ArrayColumns {
       * The array in the first column is used for keys.
       * The array in the second column is used for values.
       *
-      * @throws RuntimeException if arrays doesn't have the same length.
-      * @throws RuntimeException if a key is null
+      * @throws java.lang.RuntimeException if arrays doesn't have the same length.
+      *                                    or if a key is null
       *
       * @group Array Type
       * @see [[org.apache.spark.sql.functions.map_from_arrays]]
@@ -652,8 +656,8 @@ private[syntax] trait ArrayColumns {
       * The array in the first column is used for keys.
       * The array in the second column is used for values.
       *
-      * @throws RuntimeException if arrays doesn't have the same length.
-      * @throws RuntimeException if a key is null
+      * @throws java.lang.RuntimeException if arrays doesn't have the same length
+      *                                    or if a key is null
       *
       * @group Array Type
       * @see [[mapFromArrays]]
@@ -663,7 +667,7 @@ private[syntax] trait ArrayColumns {
 
     /**
       * Converts a column containing a StructType into a JSON string with the specified schema.
-      * @throws IllegalArgumentException in the case of an unsupported type.
+      * @throws java.lang.IllegalArgumentException in the case of an unsupported type.
       *
       * @group Array Type
       * @see org.apache.spark.sql.functions.to_json(e:org\.apache\.spark\.sql\.Column,options:scala\.collection\.immutable\.Map\[java\.lang\.String,java\.lang\.String\]):* org.apache.spark.sql.functions.to_csv

core/src/main/scala/doric/syntax/BinaryColumns.scala

@@ -6,7 +6,7 @@ import doric.types.{BinaryType, SparkType}
 
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait BinaryColumns {
+protected trait BinaryColumns {
 
   /**
     * Concatenates multiple binary columns together into a single column.

core/src/main/scala/doric/syntax/BooleanColumns.scala

@@ -5,7 +5,7 @@ import doric.DoricColumn.sparkFunction
 
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait BooleanColumns {
+protected trait BooleanColumns {
 
   /**
     * Inversion of boolean expression, i.e. NOT.

core/src/main/scala/doric/syntax/CommonColumns.scala

@@ -8,7 +8,7 @@ import doric.types.{Casting, SparkType, UnsafeCasting}
 import org.apache.spark.sql.{Column, functions => f}
 import org.apache.spark.sql.catalyst.expressions.ArrayRepeat
 
-private[syntax] trait CommonColumns extends ColGetters[NamedDoricColumn] {
+protected trait CommonColumns extends ColGetters[NamedDoricColumn] {
 
   /**
     * Returns the first column that is not null, or null if all inputs are null.

core/src/main/scala/doric/syntax/ControlStructures.scala

@@ -3,7 +3,7 @@ package syntax
 
 import doric.types.SparkType
 
-private[syntax] trait ControlStructures {
+protected trait ControlStructures {
 
   /**
     * Initialize a when builder

core/src/main/scala/doric/syntax/DStructs.scala

@@ -14,7 +14,7 @@ import shapeless.{::, HList, LabelledGeneric, Witness}
 import scala.jdk.CollectionConverters._
 import scala.language.dynamics
 
-private[syntax] trait DStructs {
+protected trait DStructs {
 
   /**
     * Creates a struct with the columns

core/src/main/scala/doric/syntax/DateColumns.scala

@@ -9,7 +9,7 @@ import java.sql.Date
 import org.apache.spark.sql.{Column, functions => f}
 import org.apache.spark.sql.catalyst.expressions.{AddMonths, CurrentDate, DateAdd, DateFormatClass, DateSub, MonthsBetween, NextDay, TruncDate, TruncTimestamp}
 
-private[syntax] trait DateColumns {
+protected trait DateColumns {
 
   /**
     * Returns the current date at the start of query evaluation as a date column.

core/src/main/scala/doric/syntax/LiteralConversions.scala

@@ -5,7 +5,7 @@ import doric.sem.Location
 import doric.types.SparkType.Primitive
 import doric.types.{LiteralSparkType, SparkType}
 
-private[syntax] trait LiteralConversions {
+protected trait LiteralConversions {
 
   /**
     * Creates a literal with the provided value.

core/src/main/scala/doric/syntax/MapColumns.scala

@@ -8,7 +8,7 @@ import org.apache.spark.sql.{Column, Row, functions => f}
 
 import scala.jdk.CollectionConverters._
 
-private[syntax] trait MapColumns {
+protected trait MapColumns {
 
   /**
     * Returns the union of all the given maps.

core/src/main/scala/doric/syntax/NumericColumns.scala

@@ -7,7 +7,7 @@ import doric.types.{CollectionType, NumericType}
 import org.apache.spark.sql.catalyst.expressions.{BRound, FormatNumber, FromUnixTime, Rand, Randn, Round, UnaryMinus}
 import org.apache.spark.sql.{Column, functions => f}
 
-private[syntax] trait NumericColumns {
+protected trait NumericColumns {
 
   /**
     * Returns the current Unix timestamp (in seconds) as a long.

core/src/main/scala/doric/syntax/StringColumns.scala

@@ -8,7 +8,7 @@ import org.apache.spark.sql.{Column, functions => f}
 
 import scala.jdk.CollectionConverters._
 
-private[syntax] trait StringColumns {
+protected trait StringColumns {
 
   /**
     * Concatenate string columns to form a single one

core/src/main/scala/doric/syntax/TimestampColumns.scala

@@ -7,7 +7,7 @@ import doric.types.{SparkType, TimestampType}
 import org.apache.spark.sql.{Column, functions => f}
 import org.apache.spark.sql.catalyst.expressions.{FromUTCTimestamp, ToUTCTimestamp}
 
-private[syntax] trait TimestampColumns {
+protected trait TimestampColumns {
 
   /**
     * Returns the current timestamp at the start of query evaluation as a timestamp column.

core/src/main/scala/doric/syntax/package.scala

@@ -20,7 +20,7 @@ package object syntax {
     * @tparam K type of "key" doric column to perform the search
     * @tparam V type of "value" doric column result
     */
-  @inline private[syntax] def elementAtAbstract[T, K, V](
+  @inline def elementAtAbstract[T, K, V](
       dc: DoricColumn[T],
       key: DoricColumn[K]
   ): DoricColumn[V] = {
@@ -39,7 +39,7 @@ package object syntax {
     * @param dc doric column to be reversed
     * @tparam T type of doric column (string or array)
     */
-  @inline private[syntax] def reverseAbstract[T](
+  @inline def reverseAbstract[T](
       dc: DoricColumn[T]
   ): DoricColumn[T] =
     dc.elem.map(f.reverse).toDC

core/src/main/spark_2.4_3.0_3.1/scala/doric/syntax/BinaryColumns30_31.scala

@@ -7,7 +7,7 @@ import doric.types.{BinaryType, SparkType}
 import org.apache.spark.sql.catalyst.expressions.Decode
 import org.apache.spark.sql.Column
 
-private[syntax] trait BinaryColumns30_31 {
+protected trait BinaryColumns30_31 {
 
   implicit class BinaryOperationsSyntax30_31[T: BinaryType: SparkType](
       column: DoricColumn[T]

core/src/main/spark_2.4_3.0_3.1/scala/doric/syntax/NumericColumns2_31.scala

@@ -6,7 +6,7 @@ import org.apache.spark.sql.Column
 import org.apache.spark.sql.{functions => f}
 import org.apache.spark.sql.catalyst.expressions.{ShiftLeft, ShiftRight, ShiftRightUnsigned}
 
-private[syntax] trait NumericColumns2_31 {
+protected trait NumericColumns2_31 {
 
   /**
     * INTEGRAL OPERATIONS

core/src/main/spark_3.1_3.2_3.3/scala/doric/syntax/AggregationColumns31.scala

@@ -5,7 +5,7 @@ import doric.types.DoubleC
 
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait AggregationColumns31 {
+protected trait AggregationColumns31 {
 
   /**
     * Aggregate function: returns the approximate `percentile` of the numeric column `col` which

core/src/main/spark_3.1_3.2_3.3/scala/doric/syntax/BooleanColumns31.scala

@@ -5,7 +5,7 @@ import cats.implicits._
 
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait BooleanColumns31 {
+protected trait BooleanColumns31 {
 
   /**
     * @group Boolean Type

core/src/main/spark_3.1_3.2_3.3/scala/doric/syntax/NumericColumns31.scala

@@ -4,7 +4,7 @@ package syntax
 import doric.types.NumericType
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait NumericColumns31 {
+protected trait NumericColumns31 {
   implicit class NumericOperationsSyntax31[T: NumericType](
       column: DoricColumn[T]
   ) {

core/src/main/spark_3.1_3.2_3.3/scala/doric/syntax/StringColumns31.scala

@@ -4,7 +4,7 @@ package syntax
 import doric.sem.Location
 import org.apache.spark.sql.{functions => f}
 
-private[syntax] trait StringColumns31 {
+protected trait StringColumns31 {
 
   /**
     * Throws an exception with the provided error message.

core/src/main/spark_3.2_3.3/scala/doric/syntax/BinaryColumns32.scala

@@ -7,7 +7,7 @@ import doric.types.{BinaryType, SparkType}
 import org.apache.spark.sql.Column
 import org.apache.spark.sql.catalyst.expressions.StringDecode
 
-private[syntax] trait BinaryColumns32 {
+protected trait BinaryColumns32 {
 
   implicit class BinaryOperationsSyntax32[T: BinaryType: SparkType](
       column: DoricColumn[T]

core/src/main/spark_3.2_3.3/scala/doric/syntax/NumericColumns32.scala

@@ -6,7 +6,7 @@ import org.apache.spark.sql.Column
 import org.apache.spark.sql.{functions => f}
 import org.apache.spark.sql.catalyst.expressions.{ShiftLeft, ShiftRight, ShiftRightUnsigned}
 
-private[syntax] trait NumericColumns32 {
+protected trait NumericColumns32 {
 
   /**
     * INTEGRAL OPERATIONS