Class SolrRules

solr/modules/sql/src/java/org/apache/solr/handler/sql/SolrRules.java:44–222

Rules and relational operators for SolrRel#CONVENTION calling convention.

/** Rules and relational operators for {@link SolrRel#CONVENTION} calling convention. */
class SolrRules {
  static final RelOptRule[] RULES = {
    SolrSortRule.SORT_RULE,
    SolrFilterRule.FILTER_RULE,
    SolrProjectRule.PROJECT_RULE,
    SolrAggregateRule.AGGREGATE_RULE,
  };

  static List<String> solrFieldNames(final RelDataType rowType) {
    return SqlValidatorUtil.uniquify(
        new AbstractList<>() {
          @Override
          public String get(int index) {
            return rowType.getFieldList().get(index).getName();
          }

          @Override
          public int size() {
            return rowType.getFieldCount();
          }
        },
        true);
  }

  /** Translator from {@link RexNode} to strings in Solr's expression language. */
  static class RexToSolrTranslator extends RexVisitorImpl<String> {
    private final List<String> inFields;

    RexToSolrTranslator(List<String> inFields) {
      super(true);
      this.inFields = inFields;
    }

    @Override
    public String visitInputRef(RexInputRef inputRef) {
      return inFields.get(inputRef.getIndex());
    }

    @Override
    public String visitCall(RexCall call) {
      final List<String> strings = visitList(call.operands);
      if (call.getKind() == SqlKind.CAST) {
        return strings.get(0);
      }

      return super.visitCall(call);
    }

    private List<String> visitList(List<RexNode> list) {
      final List<String> strings = new ArrayList<>();
      for (RexNode node : list) {
        strings.add(node.accept(this));
      }
      return strings;
    }
  }

  /**