Extend dart:typed_data support to other currently supported List types

dart/lib/flat_buffers.dart

@@ -52,6 +52,24 @@ class BufferContext {
     return _buffer.buffer.asUint16List(_buffer.offsetInBytes + offset, length);
   }
 
+  @pragma('vm:prefer-inline')
+  Uint32List _asUint32List(int offset, int length) {
+    assert(Endian.host == Endian.little);
+    return _buffer.buffer.asUint32List(_buffer.offsetInBytes + offset, length);
+  }
+
+  @pragma('vm:prefer-inline')
+  Float32List _asFloat32List(int offset, int length) {
+    assert(Endian.host == Endian.little);
+    return _buffer.buffer.asFloat32List(_buffer.offsetInBytes + offset, length);
+  }
+
+  @pragma('vm:prefer-inline')
+  Float64List _asFloat64List(int offset, int length) {
+    assert(Endian.host == Endian.little);
+    return _buffer.buffer.asFloat64List(_buffer.offsetInBytes + offset, length);
+  }
+
   @pragma('vm:prefer-inline')
   double _getFloat64(int offset) => _buffer.getFloat64(offset, Endian.little);
 
@@ -897,8 +915,15 @@ class Float64ListReader extends Reader<List<double>> {
 
   @override
   @pragma('vm:prefer-inline')
-  List<double> read(BufferContext bc, int offset) =>
-      _FbFloat64List(bc, bc.derefObject(offset));
+  List<double> read(BufferContext bc, int offset) {
+    if (Endian.host == Endian.little) {
+        final listOffset = bc.derefObject(offset);
+        final length = bc._getUint32(listOffset);
+        return bc._asFloat64List(listOffset + _sizeofUint32, length);
+	  } else {
+        return _FbFloat64List(bc, bc.derefObject(offset));
+	  }
+  }
 }
 
 class Float32ListReader extends Reader<List<double>> {
@@ -910,8 +935,15 @@ class Float32ListReader extends Reader<List<double>> {
 
   @override
   @pragma('vm:prefer-inline')
-  List<double> read(BufferContext bc, int offset) =>
-      _FbFloat32List(bc, bc.derefObject(offset));
+  List<double> read(BufferContext bc, int offset) {
+    if (Endian.host == Endian.little) {
+        final listOffset = bc.derefObject(offset);
+        final length = bc._getUint32(listOffset);
+        return bc._asFloat32List(listOffset + _sizeofUint32, length);
+	  } else {
+        return _FbFloat32List(bc, bc.derefObject(offset));
+	  }
+  }
 }
 
 class Float64Reader extends Reader<double> {
@@ -1131,8 +1163,16 @@ class Uint32ListReader extends Reader<List<int>> {
 
   @override
   @pragma('vm:prefer-inline')
-  List<int> read(BufferContext bc, int offset) =>
-      _FbUint32List(bc, bc.derefObject(offset));
+  List<int> read(BufferContext bc, int offset) {
+    if (Endian.host == Endian.little) {
+        final listOffset = bc.derefObject(offset);
+        final length = bc._getUint32(listOffset);
+        return bc._asUint32List(listOffset + _sizeofUint32, length);
+	  } else {
+        return _FbUint32List(bc, bc.derefObject(offset));
+	  }
+  }
+      
 }
 
 /// The reader of unsigned 64-bit integers.

dart/test/flat_buffers_test.dart

@@ -1,3 +1,5 @@
+// ignore_for_file: non_constant_identifier_names
+
 import 'dart:typed_data';
 import 'dart:io' as io;
 
@@ -543,7 +545,7 @@ class BuilderTest {
     // read and verify
     BufferContext buf = BufferContext.fromBytes(byteList);
     List<double> items = const Float64ListReader().read(buf, 0);
-
+    expect(items is Float64List, Endian.host == Endian.little);
     expect(items, hasLength(values.length));
     for (int i = 0; i < values.length; i++) {
       expect(values[i], closeTo(items[i], .001));
@@ -563,6 +565,7 @@ class BuilderTest {
     // read and verify
     BufferContext buf = BufferContext.fromBytes(byteList);
     List<double> items = const Float32ListReader().read(buf, 0);
+    expect(items is Float32List, Endian.host == Endian.little);
     expect(items, hasLength(5));
     for (int i = 0; i < values.length; i++) {
       expect(values[i], closeTo(items[i], .001));
@@ -655,6 +658,7 @@ class BuilderTest {
     // read and verify
     BufferContext buf = BufferContext.fromBytes(byteList);
     List<int> items = const Uint32ListReader().read(buf, 0);
+    expect(items is Uint32List, Endian.host == Endian.little);
     expect(items, hasLength(3));
     expect(items, orderedEquals(<int>[1, 2, 0x9ABCDEF0]));
   }
@@ -670,7 +674,7 @@ class BuilderTest {
     // read and verify
     BufferContext buf = BufferContext.fromBytes(byteList);
     List<int> items = const Uint16ListReader().read(buf, 0);
-    expect(items is Uint16List, true, skip: Endian.host == Endian.big);
+    expect(items is Uint16List, Endian.host == Endian.little);
     expect(items, hasLength(3));
     expect(items, orderedEquals(<int>[1, 2, 60000]));
   }
@@ -845,9 +849,9 @@ class ObjectAPITest {
     final offset = monster.pack(fbBuilder);
     expect(offset, isNonZero);
     fbBuilder.finish(offset);
-    final data = fbBuilder.buffer;
 
     // TODO currently broken because of struct builder issue, see #6688
+    // final data = fbBuilder.buffer;
     // final monster2 = example.Monster(data); // Monster (reader)
     // expect(
     //     // map Monster => MonsterT, Vec3 => Vec3T, ...