[DRAFT] Array Support POC

common/src/main/java/org/opensearch/sql/common/utils/StringUtils.java

@@ -105,4 +105,8 @@ public static String format(final String format, Object... args) {
   private static boolean isQuoted(String text, String mark) {
     return !Strings.isNullOrEmpty(text) && text.startsWith(mark) && text.endsWith(mark);
   }
+
+  public static String removeParenthesis(String qualifier) {
+    return qualifier.replaceAll("\\[\\d+\\]", "");
+  }
 }

core/src/main/java/org/opensearch/sql/analysis/ExpressionAnalyzer.java

@@ -17,14 +17,17 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
+import java.util.OptionalInt;
 import java.util.stream.Collectors;
 import lombok.Getter;
+import org.apache.commons.lang3.tuple.Pair;
 import org.opensearch.sql.analysis.symbol.Namespace;
 import org.opensearch.sql.analysis.symbol.Symbol;
 import org.opensearch.sql.ast.AbstractNodeVisitor;
 import org.opensearch.sql.ast.expression.AggregateFunction;
 import org.opensearch.sql.ast.expression.AllFields;
 import org.opensearch.sql.ast.expression.And;
+import org.opensearch.sql.ast.expression.ArrayQualifiedName;
 import org.opensearch.sql.ast.expression.Between;
 import org.opensearch.sql.ast.expression.Case;
 import org.opensearch.sql.ast.expression.Cast;
@@ -49,14 +52,15 @@
 import org.opensearch.sql.ast.expression.When;
 import org.opensearch.sql.ast.expression.WindowFunction;
 import org.opensearch.sql.ast.expression.Xor;
-import org.opensearch.sql.common.antlr.SyntaxCheckException;
+import org.opensearch.sql.common.utils.StringUtils;
 import org.opensearch.sql.data.model.ExprValueUtils;
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.exception.SemanticCheckException;
 import org.opensearch.sql.expression.DSL;
 import org.opensearch.sql.expression.Expression;
 import org.opensearch.sql.expression.HighlightExpression;
+import org.opensearch.sql.expression.ArrayReferenceExpression;
 import org.opensearch.sql.expression.LiteralExpression;
 import org.opensearch.sql.expression.NamedArgumentExpression;
 import org.opensearch.sql.expression.NamedExpression;
@@ -368,8 +372,28 @@ public Expression visitAllFields(AllFields node, AnalysisContext context) {
   public Expression visitQualifiedName(QualifiedName node, AnalysisContext context) {
     QualifierAnalyzer qualifierAnalyzer = new QualifierAnalyzer(context);
 
-    // check for reserved words in the identifier
-    for (String part : node.getParts()) {
+    Expression reserved = checkForReservedIdentifier(node.getParts(), context, qualifierAnalyzer, node);
+    if (reserved != null) {
+      return reserved;
+    }
+
+    return visitIdentifier(qualifierAnalyzer.unqualified(node), context);
+  }
+
+  @Override
+  public Expression visitArrayQualifiedName(ArrayQualifiedName node, AnalysisContext context) {
+    QualifierAnalyzer qualifierAnalyzer = new QualifierAnalyzer(context);
+
+    Expression reserved = checkForReservedIdentifier(node.getParts(), context, qualifierAnalyzer, node);
+    if (reserved != null) {
+      return reserved;
+    }
+
+    return visitArrayIdentifier(qualifierAnalyzer.unqualified(node), context, node.getPartsAndIndexes());
+  }
+
+  private Expression checkForReservedIdentifier(List<String> parts, AnalysisContext context, QualifierAnalyzer qualifierAnalyzer, QualifiedName node) {
+    for (String part : parts) {
       for (TypeEnvironment typeEnv = context.peek();
            typeEnv != null;
            typeEnv = typeEnv.getParent()) {
@@ -384,7 +408,7 @@ public Expression visitQualifiedName(QualifiedName node, AnalysisContext context
         }
       }
     }
-    return visitIdentifier(qualifierAnalyzer.unqualified(node), context);
+    return null;
   }
 
   @Override
@@ -422,9 +446,27 @@ private Expression visitIdentifier(String ident, AnalysisContext context) {
     }
 
     TypeEnvironment typeEnv = context.peek();
+    var type = typeEnv.resolve(new Symbol(Namespace.FIELD_NAME, ident));
     ReferenceExpression ref = DSL.ref(ident,
-        typeEnv.resolve(new Symbol(Namespace.FIELD_NAME, ident)));
+            typeEnv.resolve(new Symbol(Namespace.FIELD_NAME, ident)));
 
+    if (type.equals(ExprCoreType.ARRAY)) {
+      return new ArrayReferenceExpression(ref);
+    }
     return ref;
   }
+
+  private Expression visitArrayIdentifier(String ident, AnalysisContext context,
+      List<Pair<String, OptionalInt>> partsAndIndexes) {
+    // ParseExpression will always override ReferenceExpression when ident conflicts
+    for (NamedExpression expr : context.getNamedParseExpressions()) {
+      if (expr.getNameOrAlias().equals(ident) && expr.getDelegated() instanceof ParseExpression) {
+        return expr.getDelegated();
+      }
+    }
+
+    TypeEnvironment typeEnv = context.peek();
+    return new ArrayReferenceExpression(ident,
+        typeEnv.resolve(new Symbol(Namespace.FIELD_NAME, StringUtils.removeParenthesis(ident))), partsAndIndexes);
+  }
 }

core/src/main/java/org/opensearch/sql/analysis/QualifierAnalyzer.java

@@ -11,8 +11,10 @@
 import lombok.RequiredArgsConstructor;
 import org.opensearch.sql.analysis.symbol.Namespace;
 import org.opensearch.sql.analysis.symbol.Symbol;
+import org.opensearch.sql.ast.expression.ArrayQualifiedName;
 import org.opensearch.sql.ast.expression.QualifiedName;
 import org.opensearch.sql.common.antlr.SyntaxCheckException;
+import org.opensearch.sql.common.utils.StringUtils;
 import org.opensearch.sql.exception.SemanticCheckException;
 
 /**
@@ -38,6 +40,10 @@ public String unqualified(QualifiedName fullName) {
     return isQualifierIndexOrAlias(fullName) ? fullName.rest().toString() : fullName.toString();
   }
 
+  public String unqualified(ArrayQualifiedName fullName) {
+    return isQualifierIndexOrAlias(fullName) ? fullName.rest().toString() : fullName.toString();
+  }
+
   private boolean isQualifierIndexOrAlias(QualifiedName fullName) {
     Optional<String> qualifier = fullName.first();
     if (qualifier.isPresent()) {
@@ -50,10 +56,22 @@ private boolean isQualifierIndexOrAlias(QualifiedName fullName) {
     return false;
   }
 
+  private boolean isQualifierIndexOrAlias(ArrayQualifiedName fullName) {
+    Optional<String> qualifier = fullName.first();
+    if (qualifier.isPresent()) {
+      if (isFieldName(qualifier.get())) {
+        return false;
+      }
+      resolveQualifierSymbol(fullName, qualifier.get());
+      return true;
+    }
+    return false;
+  }
+
   private boolean isFieldName(String qualifier) {
     try {
       // Resolve the qualifier in Namespace.FIELD_NAME
-      context.peek().resolve(new Symbol(Namespace.FIELD_NAME, qualifier));
+      context.peek().resolve(new Symbol(Namespace.FIELD_NAME, StringUtils.removeParenthesis(qualifier)));
       return true;
     } catch (SemanticCheckException e2) {
       return false;

core/src/main/java/org/opensearch/sql/analysis/SelectExpressionAnalyzer.java

@@ -23,9 +23,11 @@
 import org.opensearch.sql.ast.expression.NestedAllTupleFields;
 import org.opensearch.sql.ast.expression.QualifiedName;
 import org.opensearch.sql.ast.expression.UnresolvedExpression;
+import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.expression.DSL;
 import org.opensearch.sql.expression.Expression;
+import org.opensearch.sql.expression.ArrayReferenceExpression;
 import org.opensearch.sql.expression.NamedExpression;
 import org.opensearch.sql.expression.ReferenceExpression;
 
@@ -105,8 +107,17 @@ public List<NamedExpression> visitAllFields(AllFields node,
                                               AnalysisContext context) {
     TypeEnvironment environment = context.peek();
     Map<String, ExprType> lookupAllFields = environment.lookupAllFields(Namespace.FIELD_NAME);
-    return lookupAllFields.entrySet().stream().map(entry -> DSL.named(entry.getKey(),
-        new ReferenceExpression(entry.getKey(), entry.getValue()))).collect(Collectors.toList());
+    return lookupAllFields.entrySet().stream().map(entry ->
+        {
+          ReferenceExpression ref = new ReferenceExpression(entry.getKey(), entry.getValue());
+          if (entry.getValue().equals(ExprCoreType.ARRAY)) {
+            return DSL.named(entry.getKey(),
+                new ArrayReferenceExpression(ref));
+          } else {
+            return DSL.named(entry.getKey(), ref);
+          }
+        }
+        ).collect(Collectors.toList());
   }
 
   @Override

core/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java

@@ -11,6 +11,7 @@
 import org.opensearch.sql.ast.expression.AllFields;
 import org.opensearch.sql.ast.expression.And;
 import org.opensearch.sql.ast.expression.Argument;
+import org.opensearch.sql.ast.expression.ArrayQualifiedName;
 import org.opensearch.sql.ast.expression.AttributeList;
 import org.opensearch.sql.ast.expression.Between;
 import org.opensearch.sql.ast.expression.Case;
@@ -194,6 +195,9 @@ public T visitField(Field node, C context) {
   public T visitQualifiedName(QualifiedName node, C context) {
     return visitChildren(node, context);
   }
+  public T visitArrayQualifiedName(ArrayQualifiedName node, C context) {
+    return visitChildren(node, context);
+  }
 
   public T visitRename(Rename node, C context) {
     return visitChildren(node, context);

core/src/main/java/org/opensearch/sql/ast/expression/ArrayQualifiedName.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+package org.opensearch.sql.ast.expression;
+
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import org.apache.commons.lang3.tuple.Pair;
+import org.opensearch.sql.ast.AbstractNodeVisitor;
+
+import java.util.List;
+import java.util.OptionalInt;
+import java.util.stream.Collectors;
+
+@Getter
+@EqualsAndHashCode(callSuper = false)
+public class ArrayQualifiedName extends QualifiedName {
+
+  private final List<Pair<String, OptionalInt>> partsAndIndexes;
+
+  public ArrayQualifiedName(List<Pair<String, OptionalInt>> parts) {
+    super(parts.stream().map(p -> p.getLeft()).collect(Collectors.toList()));
+    this.partsAndIndexes = parts;
+  }
+
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitArrayQualifiedName(this, context);
+  }
+}

core/src/main/java/org/opensearch/sql/expression/ArrayReferenceExpression.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+package org.opensearch.sql.expression;
+
+import static org.opensearch.sql.utils.ExpressionUtils.PATH_SEP;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.OptionalInt;
+import java.util.stream.Collectors;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import org.apache.commons.lang3.tuple.Pair;
+import org.opensearch.sql.common.utils.StringUtils;
+import org.opensearch.sql.data.model.ExprCollectionValue;
+import org.opensearch.sql.data.model.ExprMissingValue;
+import org.opensearch.sql.data.model.ExprTupleValue;
+import org.opensearch.sql.data.model.ExprValue;
+import org.opensearch.sql.data.model.ExprValueUtils;
+import org.opensearch.sql.data.type.ExprCoreType;
+import org.opensearch.sql.data.type.ExprType;
+import org.opensearch.sql.expression.env.Environment;
+
+@EqualsAndHashCode
+public class ArrayReferenceExpression extends ReferenceExpression {
+  @Getter
+  private final List<Pair<String, OptionalInt>> partsAndIndexes;
+  @Getter
+  private final ExprType type;
+  public ArrayReferenceExpression(String ref, ExprType type, List<Pair<String, OptionalInt>> partsAndIndexes) {
+    super(StringUtils.removeParenthesis(ref), type);
+    this.partsAndIndexes = partsAndIndexes;
+    this.type = type;
+  }
+
+  public ArrayReferenceExpression(ReferenceExpression ref) {
+    super(StringUtils.removeParenthesis(ref.toString()), ref.type());
+    this.partsAndIndexes = Arrays.stream(ref.toString().split("\\.")).map(e -> Pair.of(e, OptionalInt.empty())).collect(
+        Collectors.toList());
+    this.type = ref.type();
+  }
+
+  @Override
+  public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+    return env.resolve(this);
+  }
+
+  @Override
+  public ExprType type() {
+    return type;
+  }
+
+  @Override
+  public <T, C> T accept(ExpressionNodeVisitor<T, C> visitor, C context) {
+    return visitor.visitArrayReference(this, context);
+  }
+
+  public ExprValue resolve(ExprTupleValue value) {
+    return resolve(value, partsAndIndexes);
+  }
+
+  private ExprValue resolve(ExprValue value, List<Pair<String, OptionalInt>> paths) {
+    List<String> pathsWithoutParenthesis =
+        paths.stream().map(p -> StringUtils.removeParenthesis(p.getLeft())).collect(Collectors.toList());
+    ExprValue wholePathValue = value.keyValue(String.join(PATH_SEP, pathsWithoutParenthesis));
+
+    if (!paths.get(0).getRight().isEmpty()) {
+      if (value.keyValue(pathsWithoutParenthesis.get(0)) instanceof ExprCollectionValue) { // TODO check array size
+        wholePathValue = value
+            .keyValue(pathsWithoutParenthesis.get(0))
+            .collectionValue()
+            .get(paths.get(0).getRight().getAsInt());
+        if (paths.size() != 1) {
+          return resolve(wholePathValue, paths.subList(1, paths.size()));
+        }
+      } else {
+        return ExprValueUtils.missingValue();
+      }
+    } else if (wholePathValue.isMissing()) {
+      return resolve(value.keyValue(pathsWithoutParenthesis.get(0)), paths.subList(1, paths.size()));
+    }
+
+    if (!wholePathValue.isMissing() || paths.size() == 1) {
+      return wholePathValue;
+    } else {
+      return resolve(value.keyValue(pathsWithoutParenthesis.get(0)), paths.subList(1, paths.size()));
+    }
+  }
+}

core/src/main/java/org/opensearch/sql/expression/ExpressionNodeVisitor.java

@@ -64,6 +64,10 @@ public T visitReference(ReferenceExpression node, C context) {
     return visitNode(node, context);
   }
 
+  public T visitArrayReference(ArrayReferenceExpression node, C context) {
+    return visitNode(node, context);
+  }
+
   public T visitParse(ParseExpression node, C context) {
     return visitNode(node, context);
   }

core/src/main/java/org/opensearch/sql/expression/HighlightExpression.java

@@ -51,7 +51,7 @@ public ExprValue valueOf(Environment<Expression, ExprValue> valueEnv) {
     if (this.type == ExprCoreType.ARRAY) {
       refName += "." + StringUtils.unquoteText(getHighlightField().toString());
     }
-    ExprValue value = valueEnv.resolve(DSL.ref(refName, ExprCoreType.STRING));
+    ExprValue value = valueEnv.resolve(new ArrayReferenceExpression(DSL.ref(refName, ExprCoreType.STRING)));
 
     // In the event of multiple returned highlights and wildcard being
     // used in conjunction with other highlight calls, we need to ensure

core/src/main/java/org/opensearch/sql/expression/ReferenceExpression.java

@@ -106,11 +106,22 @@ private ExprValue resolve(ExprValue value, List<String> paths) {
     if (value.type().equals(ExprCoreType.ARRAY)) {
       wholePathValue = value.collectionValue().get(0).keyValue(paths.get(0));
     }
+    if (wholePathValue.type().equals(ExprCoreType.ARRAY)) {
+      return getFirstValueOfCollection(wholePathValue);
+    }
 
     if (!wholePathValue.isMissing() || paths.size() == 1) {
       return wholePathValue;
     } else {
       return resolve(value.keyValue(paths.get(0)), paths.subList(1, paths.size()));
     }
   }
+
+  private ExprValue getFirstValueOfCollection(ExprValue value) {
+    ExprValue collectionVal = value;
+    while(collectionVal.type().equals(ExprCoreType.ARRAY)) {
+      collectionVal = collectionVal.collectionValue().get(0);
+    }
+    return collectionVal;
+  }
 }