add or revise function description

Author: aaronshan

README.md

@@ -51,19 +51,19 @@ You can also directly download file from [release page](https://github.com/aaron
 
 | function| description |
 |:--|:--|
-|array_contains(array, value) -> boolean | whether ARRAY contains value or not.|
-|array_intersect(array, array) -> array | returns the two array's intersection, without duplicates..|
+|array_contains(array<E>, E) -> boolean | whether array contains value or not.|
+|array_intersect(array, array) -> array | returns the two array's intersection, without duplicates.|
 |array_max(array<E>) -> E | returns the maximum value of input array.|
 |array_min(array<E>) -> E | returns the minimum value of input array.|
 |array_join(array, delimiter, null_replacement) -> string | concatenates the elements of the given array using the delimiter and an optional `null_replacement` to replace nulls.|
 |array_distinct(array) -> array | remove duplicate values from the array.|
-|array_position(array, value) -> long | returns the position of the first occurrence of the element in array (or 0 if not found).|
-|array_remove(array, value) -> array | remove all elements that equal element from array.|
+|array_position(array<E>, E) -> long | returns the position of the first occurrence of the element in array (or 0 if not found).|
+|array_remove(array<E>, E) -> array | remove all elements that equal element from array.|
 |array_reverse(array) -> array | reverse the array element.|
-|array_sort(array) -> array | sorts and returns the array x. The elements of x must be orderable..|
+|array_sort(array) -> array | sorts and returns the array. The elements of array must be orderable.|
 |array_concat(array, array) -> array | concatenates two arrays.|
-|array_value_count(array, value) -> long | count ARRAY's element number that element value equals given value.|
-|array_slice(array, start, length) -> array | subsets array starting from index start (or starting from the end if start is negative) with a length of length|
+|array_value_count(array<E>, E) -> long | count array's element number that element value equals given value.|
+|array_slice(array, start, length) -> array | subsets array starting from index start (or starting from the end if start is negative) with a length of length.|
 |array_element_at(array<E>, index) -> E | returns element of array at given index. If index < 0, element_at accesses elements from the last to the first.|
 
 ### 3. date functions
@@ -79,7 +79,7 @@ You can also directly download file from [release page](https://github.com/aaron
 | function| description |
 |:--|:--|
 |json_array_get(json, jsonPath) -> array(varchar) |returns the element at the specified index into the `json_array`. The index is zero-based.|
-|json_array_length(json, jsonPath) -> array(varchar) |Returns the array length of `json` (a string containing a JSON array).|
+|json_array_length(json, jsonPath) -> array(varchar) |returns the array length of `json` (a string containing a JSON array).|
 |json_array_extract(json, jsonPath) -> array(varchar) |extract json array by given jsonPath.|
 |json_array_extract_scalar(json, jsonPath) -> array(varchar) |like `json_array_extract`, but returns the result value as a string (as opposed to being encoded as JSON).|
 |json_extract(json, jsonPath) -> array(varchar) |extract json by given jsonPath.|

src/main/java/cc/shanruifeng/functions/array/UDFArrayConcat.java

@@ -1,6 +1,7 @@
 package cc.shanruifeng.functions.array;
 
 import java.util.ArrayList;
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -13,6 +14,9 @@
  * @date 2016-07-26
  * @time 17:30
  */
+@Description(name = "array_concat"
+        , value = "_FUNC_(array, array) - concatenates two arrays."
+        , extended = "Example:\n > select _FUNC_(array, array) from src;")
 public class UDFArrayConcat extends GenericUDF {
     private static final int ARG_COUNT = 2; // Number of arguments to this UDF
     private transient ListObjectInspector leftArrayOI;

src/main/java/cc/shanruifeng/functions/array/UDFArrayContains.java

@@ -1,5 +1,6 @@
 package cc.shanruifeng.functions.array;
 
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -15,6 +16,9 @@
  * @author ruifeng.shan
  * @date 2015-3-23
  */
+@Description(name = "array_contains"
+        , value = "_FUNC_(array<E>, E) - whether array contains value or not."
+        , extended = "Example:\n > select _FUNC_(array, value) from src;")
 public class UDFArrayContains extends GenericUDF {
 
     private static final int ARRAY_IDX = 0;

src/main/java/cc/shanruifeng/functions/array/UDFArrayDistinct.java

@@ -2,6 +2,7 @@
 
 import it.unimi.dsi.fastutil.ints.IntArrays;
 import java.util.ArrayList;
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -16,6 +17,9 @@
  * @date 2016-07-26
  * @time 17:29
  */
+@Description(name = "array_distinct"
+        , value = "_FUNC_(array) - remove duplicate values from the array."
+        , extended = "Example:\n > select _FUNC_(array) from src;")
 public class UDFArrayDistinct extends GenericUDF {
     private static final int INITIAL_SIZE = 128;
     private static final int ARG_COUNT = 1; // Number of arguments to this UDF

src/main/java/cc/shanruifeng/functions/array/UDFArrayElementAt.java

@@ -1,5 +1,6 @@
 package cc.shanruifeng.functions.array;
 
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -16,6 +17,9 @@
  * @date 2016-07-27
  * @time 10:09
  */
+@Description(name = "array_element_at"
+        , value = "_FUNC_(array<E>, index) - returns element of array at given index. If index < 0, element_at accesses elements from the last to the first."
+        , extended = "Example:\n > select _FUNC_(array, index) from src;")
 public class UDFArrayElementAt extends GenericUDF {
 
     private static final int ARRAY_IDX = 0;

src/main/java/cc/shanruifeng/functions/array/UDFArrayIntersect.java

@@ -2,6 +2,7 @@
 
 import it.unimi.dsi.fastutil.ints.IntArrays;
 import java.util.ArrayList;
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -17,6 +18,9 @@
  * @date 2016-07-26
  * @time 11:57
  */
+@Description(name = "array_intersect"
+        , value = "_FUNC_(array, array) - returns the two array's intersection, without duplicates."
+        , extended = "Example:\n > select _FUNC_(array, array) from src;")
 public class UDFArrayIntersect extends GenericUDF {
     private static final int INITIAL_SIZE = 128;
     private static final int ARG_COUNT = 2; // Number of arguments to this UDF

src/main/java/cc/shanruifeng/functions/array/UDFArrayJoin.java

@@ -1,5 +1,6 @@
 package cc.shanruifeng.functions.array;
 
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -17,6 +18,9 @@
  * @date 2016-07-26
  * @time 17:31
  */
+@Description(name = "array_join"
+        , value = "_FUNC_(array<E>, delimiter, null_replacement) - concatenates the elements of the given array using the delimiter and an optional null_replacement to replace nulls."
+        , extended = "Example:\n > select _FUNC_(array, delimiter) from src;\n> select _FUNC_(array, delimiter, null_replacement) from src;")
 public class UDFArrayJoin extends GenericUDF {
 
     private static final int ARRAY_IDX = 0;

src/main/java/cc/shanruifeng/functions/array/UDFArrayMax.java

@@ -1,6 +1,7 @@
 package cc.shanruifeng.functions.array;
 
 import it.unimi.dsi.fastutil.ints.IntArrays;
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -17,6 +18,9 @@
  * @date 2016-07-26
  * @time 17:31
  */
+@Description(name = "array_max"
+        , value = "_FUNC_(array) - returns the maximum value of input array."
+        , extended = "Example:\n > select _FUNC_(array) from src;")
 public class UDFArrayMax extends GenericUDF {
     private static final int INITIAL_SIZE = 128;
     private static final int ARG_COUNT = 1; // Number of arguments to this UDF

src/main/java/cc/shanruifeng/functions/array/UDFArrayMin.java

@@ -1,6 +1,7 @@
 package cc.shanruifeng.functions.array;
 
 import it.unimi.dsi.fastutil.ints.IntArrays;
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -17,6 +18,9 @@
  * @date 2016-07-26
  * @time 17:32
  */
+@Description(name = "array_min"
+        , value = "_FUNC_(array) - returns the minimum value of input array."
+        , extended = "Example:\n > select _FUNC_(array) from src;")
 public class UDFArrayMin extends GenericUDF {
     private static final int INITIAL_SIZE = 128;
     private static final int ARG_COUNT = 1; // Number of arguments to this UDF

src/main/java/cc/shanruifeng/functions/array/UDFArrayPosition.java

@@ -1,5 +1,6 @@
 package cc.shanruifeng.functions.array;
 
+import org.apache.hadoop.hive.ql.exec.Description;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
 import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
@@ -16,6 +17,9 @@
  * @date 2016-07-26
  * @time 17:32
  */
+@Description(name = "array_position"
+        , value = "_FUNC_(array<E>, E) - returns the position of the first occurrence of the element in array (or 0 if not found)."
+        , extended = "Example:\n > select _FUNC_(array, value) from src;")
 public class UDFArrayPosition extends GenericUDF {
 
     private static final int ARRAY_IDX = 0;