Address comments

Author: anlowee

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpExpression.java

@@ -19,7 +19,7 @@
 
 /**
  * Represents the result of converting a Presto RowExpression into a CLP-compatible KQL query and
- * a SQL query for filtering splits by metadata database. In every case, `pushDownExpression`
+ * a SQL query for filtering splits using a metadata database. In every case, `pushDownExpression`
  * represents the part of the RowExpression that could be converted to a KQL expression, and
  * `remainingExpression` represents the part that could not be converted.
  */

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpMetadataFilterProvider.java

@@ -212,7 +212,7 @@ private Set<String> getRequiredColumnNamesFromFilters(List<Filter> filters)
 
     private Map<String, RangeMapping> getAllMappingsFromFilters(List<Filter> filters)
     {
-        return filters != null
+        return null != filters
                 ? filters.stream()
                 .filter(filter -> null != filter.rangeMapping)
                 .collect(toImmutableMap(

presto-docs/src/main/sphinx/connector/clp.rst

@@ -121,13 +121,11 @@ Each *filter* includes:
 
 - ``columnName``: must match a column name in the table’s schema.
 
-  .. note::
-     Only numeric-type columns can currently be used as metadata filters.
+  **Note:** Only numeric-type columns can currently be used as metadata filters.
 
 - ``rangeMapping`` *(optional)*: specifies how the filter should be remapped when it targets metadata-only columns.
 
-  .. note::
-     This option is only valid if the column is numeric type.
+  **Note:** This option is only valid if the column is numeric type.
 
   For example, a condition like:
 
@@ -180,6 +178,7 @@ Explanation:
 - ``"clp"``: Adds a filter on the column ``level`` for all schemas and tables under the ``clp`` catalog.
 - ``"clp.default"``: Adds a filter on ``author`` for all tables under the ``clp.default`` schema.
 - ``"clp.default.table_1"``: Adds two filters for the table ``clp.default.table_1``:
+
   - ``msg.timestamp`` is remapped via ``rangeMapping`` and is marked as **required**.
   - ``file_name`` is used as-is without remapping.