dart:convert support

[ljmatan]

Hi again,

For convenience: https://api.dart.dev/stable/2.18.2/dart-convert/dart-convert-library.html

I've referenced 3cb310c and c58466b when trying to bridge the dart:convert library.

So far I've managed to import the library and instantiate a JsonCodec instance, however, I still don't seem to be able to use any functions as I'm getting the Null check operator error. My most likely assumption is that I've done something wrong within EvalTypes from the builtins.dart file.

You can track most of what I've done so far via this commit, I'm trying to use both encode and decode functions on the JsonEncode object which I've:

1. lib/src/eval/shared/stdlib/convert/json_codec.dart
   Declared through methods parameter. I am missing some optional parameters, but I've assumed that wouldn't cause any issues.

    methods: {
      'decode': BridgeMethodDef(
        BridgeFunctionDef(
          returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.dynamicType)),
          params: [BridgeParameter('source', BridgeTypeAnnotation(_$type), false)],
          namedParams: [],
        ),
      ),
      'encode': BridgeMethodDef(
        BridgeFunctionDef(
          returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.stringType)),
          params: [BridgeParameter('value', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.objectType)), false)],
          namedParams: [],
        ),
      ),
    },

2. lib/src/eval/shared/stdlib/convert/json_codec.dart
   Declared them within $getProperty override

  @override
  $Value? $getProperty(Runtime runtime, String identifier) {
    switch (identifier) {
      case 'encoder':
        throw UnimplementedError();
      case 'decoder':
        throw UnimplementedError();
      case 'encode':
        return __encode;
      case 'decode':
        return __decode;
      default:
        return _superclass.$getProperty(runtime, identifier);
    }
  }

3. lib/src/eval/compiler/builtins.dart
   Included a new int value for dartConvertFile, I've assumed it doesn't have to be any actual value, however, I am seeing some code in the lib/src/eval/compiler/type.dart file which references dartCoreFile specifically. At this point, I'm assuming I've done something wrong in that I haven't taken into account the difference between primitive types and the new type I'm trying to introduce.

const int dartCoreFile = -1;
const int dartAsyncFile = -2;
const int dartMathFile = -3;
const int dartConvertFile = -4;

4. lib/src/eval/compiler/builtins.dart
   Added the JsonCodec type within coreDeclarations and knownMethods objects and as there appears to be a fallback to coreDeclarations in compiler.dart line 219 and 223.

'JsonCodec': EvalTypes.jsonCodecType,

static const TypeRef jsonCodecType = TypeRef(dartConvertFile, 'JsonCodec', extendsType: objectType, resolved: true);

  EvalTypes.jsonCodecType: {
    'decode': KnownMethod(AlwaysReturnType(EvalTypes.mapType, false), [KnownMethodArg('source', EvalTypes.stringType, false, false)], {}),
    'encode': KnownMethod(AlwaysReturnType(EvalTypes.stringType, false), [KnownMethodArg('value', EvalTypes.mapType, false, false)], {}),
    ..._knownObject
  }

5. Flutter:

Code sample

import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutter_eval/flutter_eval.dart';
import 'package:dart_eval/stdlib/core.dart';

class EvalAppBar extends StatefulWidget {
  const EvalAppBar({super.key});

  @override
  State<EvalAppBar> createState() => _EvalAppBarState();
}

class _EvalAppBarState extends State<EvalAppBar> {
  Widget get _title {
    final title = Text('Title');
    return title;
  }

  Widget get _searchField {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 26, vertical: 10),
      child: TextField(),
    );
  }

  @override
  Widget build(BuildContext context) {
    return EvalWidget(
      assetPath: 'assets/app_bar.evc',
      packages: const {
        'clickapo_elements': {
          'app_bar.dart': _appBarEval,
        }
      },
      library: 'package:clickapo_elements/app_bar.dart',
      function: '_AppBar',
      args: [
        $Object(_title),
        $Object(const SizedBox()),
        $Object(const SizedBox()),
        $Object(_searchField),
      ],
    );
  }
}

const _appBarEval = '''
import 'dart:convert';

import 'package:flutter/material.dart';

class _AppBar extends StatelessWidget {
  final Widget title, leading, action, bottom;

  const _AppBar(
    this.title,
    this.leading,
    this.action,
    this.bottom,
  );

  final _jsonCodec = JsonCodec();

  @override
  Widget build(BuildContext context) {
    // Uncomment below line for reproduction
    // _jsonCodec.encode({'a': 'b'});
    return Container(
      color: Colors.white,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Container(
                width: 56.0,
                height: 56.0,
                child: Center(
                  child: leading,
                ),
              ),
              title,
              Container(
                width: 56.0,
                height: 56.0,
                child: Center(
                  child: action,
                ),
              ),
            ],
          ),
          bottom,
        ],
      ),
    );
  }
}
''';

Logs

When the exception was thrown, this was the stack:
#0      _invokeWithTarget (package:dart_eval/src/eval/compiler/expression/method_invocation.dart:138:45)
#1      compileMethodInvocation (package:dart_eval/src/eval/compiler/expression/method_invocation.dart:28:12)
#2      compileExpression (package:dart_eval/src/eval/compiler/expression/expression.dart:29:12)
#3      compileArgumentListWithBridge (package:dart_eval/src/eval/compiler/helpers/argument_list.dart:215:18)
#4      compileMethodInvocation (package:dart_eval/src/eval/compiler/expression/method_invocation.dart:64:24)
#5      compileExpression (package:dart_eval/src/eval/compiler/expression/expression.dart:29:12)
#6      compileExpressionAndDiscardResult (package:dart_eval/src/eval/compiler/expression/expression.dart:79:5)
#7      compileStatement (package:dart_eval/src/eval/compiler/statement/statement.dart:21:5)
#8      compileBlock (package:dart_eval/src/eval/compiler/statement/block.dart:16:20)
#9      compileMethodDeclaration (package:dart_eval/src/eval/compiler/declaration/method.dart:50:14)
#10     compileDeclaration (package:dart_eval/src/eval/compiler/declaration/declaration.dart:18:12)
#11     compileClassDeclaration (package:dart_eval/src/eval/compiler/declaration/class.dart:29:5)
#12     compileDeclaration (package:dart_eval/src/eval/compiler/declaration/declaration.dart:16:5)
#13     Compiler.compileSources.<anonymous closure>.<anonymous closure>
(package:dart_eval/src/eval/compiler/compiler.dart:299:9)
#14     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:614:13)
#15     Compiler.compileSources.<anonymous closure> (package:dart_eval/src/eval/compiler/compiler.dart:290:13)
#16     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:614:13)
#17     Compiler.compileSources (package:dart_eval/src/eval/compiler/compiler.dart:287:30)
#18     Compiler.compile (package:dart_eval/src/eval/compiler/compiler.dart:119:12)
#19     _EvalWidgetState._recompile (package:flutter_eval/src/flutter_eval.dart:308:30)
#20     _EvalWidgetState.initState (package:flutter_eval/src/flutter_eval.dart:288:7)
#21     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5089:55)
#22     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4932:5)
...     Normal element mounting (49 frames)
#71     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3941:16)
#72     Element.updateChild (package:flutter/src/widgets/framework.dart:3670:18)
#73     SliverMultiBoxAdaptorElement.updateChild (package:flutter/src/widgets/sliver.dart:1404:37)
#74     SliverMultiBoxAdaptorElement.createChild.<anonymous closure> (package:flutter/src/widgets/sliver.dart:1389:20)
#75     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2673:19)
#76     SliverMultiBoxAdaptorElement.createChild (package:flutter/src/widgets/sliver.dart:1381:12)
#77     RenderSliverMultiBoxAdaptor._createOrObtainChild.<anonymous closure>
(package:flutter/src/rendering/sliver_multi_box_adaptor.dart:353:23)
#78     RenderObject.invokeLayoutCallback.<anonymous closure> (package:flutter/src/rendering/object.dart:2271:59)
#79     PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:1048:15)
#80     RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:2271:14)
#81     RenderSliverMultiBoxAdaptor._createOrObtainChild
(package:flutter/src/rendering/sliver_multi_box_adaptor.dart:342:5)
#82     RenderSliverMultiBoxAdaptor.addInitialChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:428:5)
#83     RenderSliverList.performLayout (package:flutter/src/rendering/sliver_list.dart:79:12)
#84     RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#85     RenderSliverEdgeInsetsPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:149:12)
#86     RenderSliverPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:386:11)
#87     RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#88     RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:516:13)
#89     RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1600:12)
#90     RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1507:20)
#91     RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#92     RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#93     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#94     RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#95     RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#96     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#97     RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#98     RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#99     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#100    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#101    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#102    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#103    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#104    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#105    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#106    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#107    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#108    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#109    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#110    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#111    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#112    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#113    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#114    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#115    RenderCustomPaint.performLayout (package:flutter/src/rendering/custom_paint.dart:552:11)
#116    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#117    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#118    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#119    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#120    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#121    ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:56:11)
#122    RenderFlex._computeSizes (package:flutter/src/rendering/flex.dart:903:45)
#123    RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:938:32)
#124    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#125    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#126    ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:56:11)
#127    RenderStack._computeSize (package:flutter/src/rendering/stack.dart:595:43)
#128    RenderStack.performLayout (package:flutter/src/rendering/stack.dart:622:12)
#129    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#130    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#131    ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:56:11)
#132    RenderFlex._computeSizes (package:flutter/src/rendering/flex.dart:903:45)
#133    RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:938:32)
#134    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#135    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#136    MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:171:12)
#137    _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:1074:7)
#138    MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:240:7)
#139    RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:410:14)
#140    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#141    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#142    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#143    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#144    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#145    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#146    _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1462:11)
#147    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#148    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#149    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#150    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#151    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#152    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#153    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#154    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#155    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#156    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#157    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#158    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#159    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#160    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#161    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#162    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#163    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#164    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#165    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#166    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#167    RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:3808:14)
#168    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#169    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#170    RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#171    RenderObject.layout (package:flutter/src/rendering/object.dart:2160:7)
#172    RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#173    _RenderTheatre.performLayout (package:flutter/src/widgets/overlay.dart:856:15)
#174    RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1998:7)
#175    PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:1012:18)
#176    RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:510:19)
#177    WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:869:13)
#178    RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:375:5)
#179    SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1271:15)
#180    SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1200:9)
#181    SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1058:5)
#182    _invoke (dart:ui/hooks.dart:145:13)
#183    PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:338:5)
#184    _drawFrame (dart:ui/hooks.dart:112:31)

From what I've gathered, the error is most likely somewhere in the EvalTypes class and is preventing me from setting the methods properly. As no required parameters had been left out, I've assumed the bindings should work, due to the "limited support" bit.

Any input into errors or on further adjustments would be highly appreciated.

[ethanblake4]

Awesome work! It does seem I've confused you a bit though haha. There are actually two separate types of compile-time bindings in dart_eval, the standard "bridge" bindings and the legacy "known method" bindings in builtins.dart - which really shouldn't be used for any new development. They're still necessary for core primitive types like ints and Strings but eventually they'll be removed altogether.

Try removing that known method stuff and let me know how it goes.