feat: expose ConverterProvider methods

Author: vbarua

isthmus/src/main/java/io/substrait/isthmus/ConverterProvider.java

@@ -91,7 +91,7 @@ public ConverterProvider(
    * {@link SqlParser.Config} is a Calcite class which controls SQL parsing behaviour like
    * identifier casing.
    */
-  protected SqlParser.Config getSqlParserConfig() {
+  public SqlParser.Config getSqlParserConfig() {
     return SqlParser.Config.DEFAULT
         .withUnquotedCasing(Casing.TO_UPPER)
         .withParserFactory(SqlDdlParserImpl.FACTORY)
@@ -102,15 +102,15 @@ protected SqlParser.Config getSqlParserConfig() {
    * {@link CalciteConnectionConfig} is a Calcite class which controls SQL processing behaviour like
    * table name case-sensitivity.
    */
-  protected CalciteConnectionConfig getCalciteConnectionConfig() {
+  public CalciteConnectionConfig getCalciteConnectionConfig() {
     return CalciteConnectionConfig.DEFAULT.set(CalciteConnectionProperty.CASE_SENSITIVE, "false");
   }
 
   /**
    * {@link SqlToRelConverter.Config} is a Calcite class which controls SQL processing behaviour
    * like field-trimming.
    */
-  protected SqlToRelConverter.Config getSqlToRelConverterConfig() {
+  public SqlToRelConverter.Config getSqlToRelConverterConfig() {
     return SqlToRelConverter.config().withTrimUnusedFields(true).withExpand(false);
   }
 
@@ -119,7 +119,7 @@ protected SqlToRelConverter.Config getSqlToRelConverterConfig() {
    * org.apache.calcite.sql.SqlOperator}s available and controls valid identifiers during SQL
    * processing.
    */
-  protected SqlOperatorTable getSqlOperatorTable() {
+  public SqlOperatorTable getSqlOperatorTable() {
     return SubstraitOperatorTable.INSTANCE;
   }
 
@@ -152,15 +152,15 @@ protected SubstraitToCalcite getSubstraitToCalcite(Prepare.CatalogReader catalog
    * A {@link SubstraitRelVisitor} converts Calcite {@link org.apache.calcite.rel.RelNode}s to
    * Substrait {@link Rel}s
    */
-  protected SubstraitRelVisitor getSubstraitRelVisitor() {
+  public SubstraitRelVisitor getSubstraitRelVisitor() {
     return new SubstraitRelVisitor(this);
   }
 
   /**
    * A {@link RexExpressionConverter} converts Calcite {@link org.apache.calcite.rex.RexNode}s to
    * Substrait equivalents.
    */
-  protected RexExpressionConverter getRexExpressionConverter(SubstraitRelVisitor srv) {
+  public RexExpressionConverter getRexExpressionConverter(SubstraitRelVisitor srv) {
     return new RexExpressionConverter(
         srv, getCallConverters(), getWindowFunctionConverter(), getTypeConverter());
   }
@@ -169,7 +169,7 @@ protected RexExpressionConverter getRexExpressionConverter(SubstraitRelVisitor s
    * {@link CallConverter}s are used to convert Calcite {@link org.apache.calcite.rex.RexCall}s to
    * Substrait equivalents.
    */
-  protected List<CallConverter> getCallConverters() {
+  public List<CallConverter> getCallConverters() {
     ArrayList<CallConverter> callConverters = new ArrayList<>();
     callConverters.add(new FieldSelectionConverter(typeConverter));
     callConverters.add(CallConverters.CASE);
@@ -191,7 +191,7 @@ protected List<CallConverter> getCallConverters() {
    *
    * <p>Override to customize the schema generation behaviour
    */
-  protected Function<Rel, CalciteSchema> getSchemaResolver() {
+  public Function<Rel, CalciteSchema> getSchemaResolver() {
     SchemaCollector schemaCollector = new SchemaCollector(this);
     return schemaCollector::toSchema;
   }
@@ -200,15 +200,15 @@ protected Function<Rel, CalciteSchema> getSchemaResolver() {
    * A {@link SubstraitRelNodeConverter} is used when converting from Substrait {@link Rel}s to
    * Calcite {@link org.apache.calcite.rel.RelNode}s.
    */
-  protected SubstraitRelNodeConverter getSubstraitRelNodeConverter(RelBuilder relBuilder) {
+  public SubstraitRelNodeConverter getSubstraitRelNodeConverter(RelBuilder relBuilder) {
     return new SubstraitRelNodeConverter(relBuilder, this);
   }
 
   /**
    * A {@link ExpressionRexConverter} converts Substrait {@link io.substrait.expression.Expression}
    * to Calcite equivalents
    */
-  protected ExpressionRexConverter getExpressionRexConverter(
+  public ExpressionRexConverter getExpressionRexConverter(
       SubstraitRelNodeConverter relNodeConverter) {
     ExpressionRexConverter erc =
         new ExpressionRexConverter(
@@ -224,7 +224,7 @@ protected ExpressionRexConverter getExpressionRexConverter(
    * A {@link RelBuilder} is a Calcite class used as a factory for creating {@link
    * org.apache.calcite.rel.RelNode}s.
    */
-  protected RelBuilder getRelBuilder(CalciteSchema schema) {
+  public RelBuilder getRelBuilder(CalciteSchema schema) {
     return RelBuilder.create(Frameworks.newConfigBuilder().defaultSchema(schema.plus()).build());
   }
 

isthmus/src/main/java/io/substrait/isthmus/DynamicConverterProvider.java

@@ -24,7 +24,7 @@ public DynamicConverterProvider(
   }
 
   @Override
-  protected List<CallConverter> getCallConverters() {
+  public List<CallConverter> getCallConverters() {
     List<CallConverter> callConverters = super.getCallConverters();
 
     SimpleExtension.ExtensionCollection dynamicExtensionCollection =
@@ -45,7 +45,7 @@ protected List<CallConverter> getCallConverters() {
   }
 
   @Override
-  protected SqlOperatorTable getSqlOperatorTable() {
+  public SqlOperatorTable getSqlOperatorTable() {
     SimpleExtension.ExtensionCollection dynamicExtensionCollection =
         ExtensionUtils.getDynamicExtensions(extensions);
     if (!dynamicExtensionCollection.scalarFunctions().isEmpty()