1 files changed, 21 insertions, 32 deletions

diff --git a/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
index 1fd4029b1a5..0b7b1ae9996 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
@@ -4,15 +4,13 @@ package com.yahoo.document.json.readers;
 import com.fasterxml.jackson.core.JsonToken;
 import com.yahoo.document.datatypes.TensorFieldValue;
 import com.yahoo.document.json.TokenBuffer;
-import com.yahoo.document.json.TokenBuffer.Token;
+import com.yahoo.slime.Inspector;
+import com.yahoo.slime.Type;
 import com.yahoo.tensor.IndexedTensor;
 import com.yahoo.tensor.MixedTensor;
 import com.yahoo.tensor.Tensor;
 import com.yahoo.tensor.TensorAddress;
 import com.yahoo.tensor.TensorType;
-import com.yahoo.tensor.TensorType.Dimension;
-
-import java.util.function.Supplier;
 
 import static com.yahoo.document.json.readers.JsonParserHelpers.*;
 import static com.yahoo.tensor.serialization.JsonFormat.decodeHexString;
@@ -39,43 +37,36 @@ public class TensorReader {
         Tensor.Builder builder = Tensor.Builder.of(tensorFieldValue.getDataType().getTensorType());
         expectOneOf(buffer.current(), JsonToken.START_OBJECT, JsonToken.START_ARRAY);
         int initNesting = buffer.nesting();
-        while (true) {
-            Supplier<Token> lookahead = buffer.lookahead();
-            Token next = lookahead.get();
-            if (TENSOR_CELLS.equals(next.name) && ! primitiveContent(next.token, lookahead.get().token)) {
-                buffer.next();
+        for (buffer.next(); buffer.nesting() >= initNesting; buffer.next()) {
+            if (TENSOR_CELLS.equals(buffer.currentName()) && ! primitiveContent(buffer)) {
                 readTensorCells(buffer, builder);
             }
-            else if (TENSOR_VALUES.equals(next.name) && builder.type().dimensions().stream().allMatch(Dimension::isIndexed)) {
-                buffer.next();
+            else if (TENSOR_VALUES.equals(buffer.currentName()) && builder.type().dimensions().stream().allMatch(d -> d.isIndexed())) {
                 readTensorValues(buffer, builder);
             }
-            else if (TENSOR_BLOCKS.equals(next.name)) {
-                buffer.next();
+            else if (TENSOR_BLOCKS.equals(buffer.currentName())) {
                 readTensorBlocks(buffer, builder);
             }
-            else if (TENSOR_TYPE.equals(next.name) && next.token == JsonToken.VALUE_STRING) {
-                buffer.next();
+            else if (TENSOR_TYPE.equals(buffer.currentName()) && buffer.current() == JsonToken.VALUE_STRING) {
                 // Ignore input tensor type
             }
-            else if (buffer.nesting() == initNesting && JsonToken.END_OBJECT == next.token) {
-                buffer.next();
-                break;
-            }
             else {
+                buffer.previous(); // Back up to the start of the enclosing block
                 readDirectTensorValue(buffer, builder);
-                break;
+                buffer.previous(); // ... and back up to the end of the enclosing block
             }
         }
         expectOneOf(buffer.current(), JsonToken.END_OBJECT, JsonToken.END_ARRAY);
         tensorFieldValue.assign(builder.build());
     }
 
-    static boolean primitiveContent(JsonToken current, JsonToken next) {
-        if (current.isScalarValue()) return true;
-        if (current == JsonToken.START_ARRAY) {
-            if (next == JsonToken.END_ARRAY) return false;
-            if (next.isScalarValue()) return true;
+    static boolean primitiveContent(TokenBuffer buffer) {
+        JsonToken cellsValue = buffer.current();
+        if (cellsValue.isScalarValue()) return true;
+        if (cellsValue == JsonToken.START_ARRAY) {
+            JsonToken firstArrayValue = buffer.peek(1);
+            if (firstArrayValue == JsonToken.END_ARRAY) return false;
+            if (firstArrayValue.isScalarValue()) return true;
         }
         return false;
     }
@@ -195,7 +186,7 @@ public class TensorReader {
         boolean hasIndexed = builder.type().dimensions().stream().anyMatch(TensorType.Dimension::isIndexed);
         boolean hasMapped = builder.type().dimensions().stream().anyMatch(TensorType.Dimension::isMapped);
 
-        if (isArrayOfObjects(buffer))
+        if (isArrayOfObjects(buffer, 0))
             readTensorCells(buffer, builder);
         else if ( ! hasMapped)
             readTensorValues(buffer, builder);
@@ -205,12 +196,10 @@ public class TensorReader {
             readTensorCells(buffer, builder);
     }
 
-    private static boolean isArrayOfObjects(TokenBuffer buffer) {
-        if (buffer.current() != JsonToken.START_ARRAY) return false;
-        Supplier<Token> lookahead = buffer.lookahead();
-        Token next;
-        while ((next = lookahead.get()).token == JsonToken.START_ARRAY) { }
-        return next.token == JsonToken.START_OBJECT;
+    private static boolean isArrayOfObjects(TokenBuffer buffer, int ahead) {
+        if (buffer.peek(ahead++) != JsonToken.START_ARRAY) return false;
+        if (buffer.peek(ahead) == JsonToken.START_ARRAY) return isArrayOfObjects(buffer, ahead); // nested array
+        return buffer.peek(ahead) == JsonToken.START_OBJECT;
     }
 
     private static TensorAddress readAddress(TokenBuffer buffer, TensorType type) {