I'm trying to run flatc -s test.idl without success. This used to work but after changing laptops I'm not able to compile the schemas anymore. If I intentionally break the test.idl, I get errors, but with correct syntax it just fails silently.
test.idl looks like this:
namespace Foo;
enum Type : byte {
type_request = 1,
type_reply = 2,
}
struct UUID {
low_bytes: ulong;
high_bytes: ulong;
}
table Request {
req_id: UUID ( required );
}
root_type Request;
table Reply {
req_id: UUID ( required );
}
root_type Reply;
Any ideas? I'm likely running different version of flatc (currently 1.7.0), has something changed?
I found the answer, it seems (only?) .fbs extensions are supported now, so changing the name and running flatc -s test.fbs works fine.
Related
I am trying to instrument my program with jaeger-tracing (c++).
I was able to view my traces when I compliled the program with yaml-cpp version 0.5.3, but when I changed my yaml-cpp version to 0.6.x, I am unable to view my traces.
Dont know why its happening.
JaegerProgram Source code;
#include <iostream>
#include<memory>
#include <yaml-cpp/yaml.h>
#include<jaegertracing/Tracer.h>
#include<chrono>
using namespace std;
// using namespace literals::chrono_literals;
void init(const char *FilePath)
{
auto yaml = YAML::LoadFile(FilePath);
auto config = jaegertracing::Config::parse(yaml);
auto tracer=jaegertracing::Tracer::make(
"example-service-2",
config,
jaegertracing::logging::consoleLogger()
);
opentracing::Tracer::InitGlobal(
static_pointer_cast<opentracing::Tracer>(tracer)
);
}
void ChildSpan(const unique_ptr<opentracing::Span>& parentSpan){
this_thread::sleep_for(chrono::milliseconds(2));
auto childSpan = opentracing::Tracer::Global()->StartSpan("Span2",{opentracing::ChildOf(&parentSpan->context())});
}
void FollowsSpan(const unique_ptr<opentracing::Span>& followFromspan){
this_thread::sleep_for(chrono::milliseconds(3));
auto followSpan = opentracing::Tracer::Global()->StartSpan("Span3",{opentracing::FollowsFrom(&followFromspan->context())});
}
void ParentSpan(){
auto span = opentracing::Tracer::Global()->StartSpan("Span1");
ChildSpan(span);
FollowsSpan(span);
this_thread::sleep_for(chrono::milliseconds(4));
}
int main()
{
init("./config.yaml");
ParentSpan();
cout<<"Hello World"<<endl;
opentracing::Tracer::Global()->Close();
return 0;
}
compiling command - g++ -std=c++1z test.cpp -L /usr/local/lib/libyaml-cpp.a -ljaegertracing -lyaml-cpp
Yaml file
disabled: false
reporter:
logSpans: true
sampler:
type: const
param: 1
OS : ubuntu 18.04
jaegerTracing : master branch version
UPDATE
after little digging I found some fact, When I parse the above mention config file try to print the result I get the same value as written in config file, but when I parse same file using yaml-cpp-0.6.x the sampler.type is showing 'remote' and sampler.param to be '0.001' and when I manually change this change these values to be same as in config.yaml it has started showing traces. The error is present in parsing the yaml file as I could clearly see different values is loaded as configuration.
Task description
I want to make sure that no derivation I install has no run-time dependency on specified set of derivation. If I ask nix-env to install package that has such run-time dependency, I want it to say that I am asking for impossible. Build-dependencies are fine. I want to avoid huge cascade rebuilds, though.
In other words, I want to make sure that derivation with name = evil never reaches my Nix store, but I am fine that it was used to build other derivations on Hydra. Here is what I tried:
Failed attempt: use derivation meta attribute
self: super: {
evil = super.evil // { meta.broken = True; };
}
but this makes nix-env to refuse install programs that has build-time dependencies on evil, for example it refuses to install go or haskell programs (which are statically linked) because compiler has some transitive dependency on evil.
Failed attempt: replace evil with something harmless
I write overlay that replaces evil:
self: super {
evil = super.harmless; # e.g super.busybox
}
it causes major cascade rebuild.
Random idea
If there is function, like this:
self: super: {
ghc = forget_about_dependencies_but_retain_hash_yes_I_know_what_I_Do [super.evil] super.ghc;
# same for rustc, go and other compilers that link statically.
}
that would be 90% solution for me.
It seems impossible to prevent some derivation from being in store, but it is possible to make sure profile does not contain run-time dependencies:
self: super: {
world = (super.buildEnv {
name = "world";
paths = with super; [ foo bar baz ];
}).overrideAttrs (_: { disallowedRequisites = [ super.evil super.ugly ]; });
}
So, if you put all derivations you want in "world", you can be sure that evil and ugly are not in dependencies. But they will be downloaded into store to build "world", even if they are not actually used by any derivations in paths.
I've been trying to get typescript building via the build servers on visualstudio.com, and I've done the normal thing of bringing typescript into source control. But I'm getting the following issue:
VSTSC : error TS5007: Build:
Cannot resolvereferenced file:
'COMPUTE_PATHS_ONLY'.
[C:\a\src\Main\RecruitCloud\RecruitCloud.csproj]
I'm aware of the encoding issues, but in all the examples I've seen the culprit file has been named in the error message.
I'm starting to think this could be down to the number of typescript files I'm compiling in the project.
Any ideas?
This is a configuration option for the VsTsc task, the one that runs the compiler. It is used in the PreComputeCompileTypeScript target. The intention is to make the VsTsc task go through all the motions, except to run the compiler. That didn't pan out on your machine, it actually did run the compiler. Which then threw a fit since it can't find a file named COMPUTE_PATHS_ONLY.
The VsTsc task is stored in C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v12.0\TypeScript\TypeScript.Tasks.dll. Looking at the assembly with a decompiler:
protected override int ExecuteTool(string pathToTool, string responseFileCommands, string commandLineCommands)
{
if (this.Configurations.Contains("--sourcemap"))
{
this.generateSourceMaps = true;
}
else
{
this.generateSourceMaps = false;
}
if (this.Configurations.Contains("--declaration"))
{
this.generateDeclarations = true;
}
else
{
this.generateDeclarations = false;
}
this.GenerateOutputPaths();
if (!responseFileCommands.Contains("COMPUTE_PATHS_ONLY"))
{
return base.ExecuteTool(pathToTool, responseFileCommands, commandLineCommands);
}
return 0;
}
Note the !responseFileCommands.Contains() test to bypass the base.ExecuteTool() call.
All I can guess is that the method doesn't look like this on your machine. With the most likely cause that you have an outdated version of TypeScript.Tasks.dll. On my machine with VS2013 Update 4 installed it is dated Nov 11, 2014 with a size of 27816 bytes.
Your best bet would be to simply resave all the files in Unicode encoding. You can do it from a quick powershell script (Change files' encoding recursively on Windows?)
Get-ChildItem *.txt | ForEach-Object {
$content = $_ | Get-Content
Set-Content -PassThru $_.Fullname $content -Encoding UTF8 -Force}
Since getting started in Dart I've been watching for a way to execute Dart (Text) Source (that the same program may well be generating dynamically) as Code. Like the infamous "eval()" function.
Recently I have caught a few hints that the communication port between Isolates support some sort of "Spawn" that seems like it could allow this "trick". In Ruby there is also the possibility to load a module dynamically as a language feature, perhaps there is some way to do this in Dart?
Any clues or a simple example will be greatly appreciated.
Thanks in advance!
Ladislav Thon provided this answer on the Dart forum:
I believe it's very safe to say that Dart will never have eval. But it will have other, more structured ways of dynamically generating code (code name mirror builders). There is nothing like that right now, though.
There are two ways of spawning an isolate: spawnFunction, which runs an existing function from the existing code in a new isolate, so nothing you are looking for, and spawnUri, which downloads code from given URI and runs it in new isolate. That is essentially dynamic code loading -- but the dynamically loaded code is isolated from the existing code. It runs in a new isolate, so the only means of communicating with it is via message passing (through ports).
You can run a string as Dart code by first constructing a data URI from it and then passing it into Isolate.spawnUri.
import 'dart:isolate';
void main() async {
final uri = Uri.dataFromString(
'''
void main() {
print("Hellooooooo from the other side!");
}
''',
mimeType: 'application/dart',
);
await Isolate.spawnUri(uri, [], null);
}
Note that you can only do this in JIT mode, which means that the only place you might benefit from it is Dart VM command line apps / package:build scripts. It will not work in Flutter release builds.
To get a result back from it, you can use ports:
import 'dart:isolate';
void main() async {
final name = 'Eval Knievel';
final uri = Uri.dataFromString(
'''
import "dart:isolate";
void main(_, SendPort port) {
port.send("Nice to meet you, $name!");
}
''',
mimeType: 'application/dart',
);
final port = ReceivePort();
await Isolate.spawnUri(uri, [], port.sendPort);
final String response = await port.first;
print(response);
}
I wrote about it on my blog.
Eval(), in Ruby at least, can execute anything from a single statement (like an assignment) to complete involved programs. There is a substantial time penalty for executing many small snippets over most any other form of execution that is possible.
Looking at the problem closer, there are at least three different functions that were at the base of the various schemes where eval might be used. Dart handles at least 2 of these in at least minimal ways.
Dart does not, nor does it look like there is any plan to support "general" script execution.
However, the NoSuchMethod method can be used to effectively implement the dynamic "injection" of variables into your local class environment. It replaces an eval() with a string that would look like this: eval( "String text = 'your first name here';" );
The second function that Dart readily supports now is the invocation of a method, that would look like this: eval( "Map map = SomeClass.some_method()" );
After messing about with this it finally dawned on me that a single simple class can be used to store the information needed to invoke a method, for a class, as a string which seems to have general utility. I can replace a big maintenance prone switch statement that might otherwise be necessary to invoke a series of methods. In Ruby this was almost trivial, however in Dart there are some fairly less than intuitive calls so I wanted to get this "trick" in one place, which fits will with doing ordering and filtering on the strings such as you may need.
Here's the code to "accumulate" as many classes (a whole library?) into a map using reflection such that the class.methodName() can be called with nothing more than a key (as a string).
Note: I used a few "helper methods" to do Map & List functions, you will probably want to replace them with straight Dart. However this code is used and tested only using the functions..
Here's the code:
//The used "Helpers" here..
MAP_add(var map, var key, var value){ if(key != null){map[key] = value;}return(map);}
Object MAP_fetch(var map, var key, [var dflt = null]) {var value = map[key];if (value==null) {value = dflt;}return( value );}
class ClassMethodMapper {
Map _helperMirrorsMap, _methodMap;
void accum_class_map(Object myClass){
InstanceMirror helperMirror = reflect(myClass);
List methodsAr = helperMirror.type.methods.values;
String classNm = myClass.toString().split("'")[1]; ///#FRAGILE
MAP_add(_helperMirrorsMap, classNm, helperMirror);
methodsAr.forEach(( method) {
String key = method.simpleName;
if (key.charCodeAt(0) != 95) { //Ignore private methods
MAP_add(_methodMap, "${classNm}.${key}()", method);
}
});
}
Map invoker( String methodNm ) {
var method = MAP_fetch(_methodMap, methodNm, null);
if (method != null) {
String classNm = methodNm.split('.')[0];
InstanceMirror helperMirror = MAP_fetch(_helperMirrorsMap, classNm);
helperMirror.invoke(method.simpleName, []);
}
}
ClassMethodMapper() {
_methodMap = {};
_helperMirrorsMap = {};
}
}//END_OF_CLASS( ClassMethodMapper );
============
main() {
ClassMethodMapper cMM = new ClassMethodMapper();
cMM.accum_class_map(MyFirstExampleClass);
cMM.accum_class_map(MySecondExampleClass);
//Now you're ready to execute any method (not private as per a special line of code above)
//by simply doing this:
cMM.invoker( MyFirstExampleClass.my_example_method() );
}
Actually there some libraries in pub.dev/packages but has some limitations because are young versions, so that I can recommend you this library expressions to dart and flutter.
A library to parse and evaluate simple expressions.
This library can handle simple expressions, but no blocks of code, control flow statements and so on. It supports a syntax that is common to most programming languages.
There I create an example of code to evaluate arithmetic operations and comparations of data.
import 'package:expressions/expressions.dart';
import 'dart:math';
#override
Widget build(BuildContext context) {
final parsing = FormulaMath();
// Expression example
String condition = "(cos(x)*cos(x)+sin(x)*sin(x)==1) && respuesta_texto == 'si'";
Expression expression = Expression.parse(condition);
var context = {
"x": pi / 5,
"cos": cos,
"sin": sin,
"respuesta_texto" : 'si'
};
// Evaluate expression
final evaluator = const ExpressionEvaluator();
var r = evaluator.eval(expression, context);
print(r);
return Scaffold(
body: Container(
margin: EdgeInsets.only(top: 50.0),
child: Column(
children: [
Text(condition),
Text(r.toString())
],
),
),
);
}
I/flutter (27188): true
I'm doing an experiment with wxWebConnect test application, incorporating the xpcom tutorial at "http://nerdlife.net/building-a-c-xpcom-component-in-windows/"
I adapt MyComponent class as necessary to compile together with testapp.exe (not as separate dll), and on MyApp::OnInit I have the following lines:
ns_smartptr<nsIComponentRegistrar> comp_reg;
res = NS_GetComponentRegistrar(&comp_reg.p);
if (NS_FAILED(res))
return false;
ns_smartptr<nsIFactory> prompt_factory;
CreateMyComponentFactory(&prompt_factory.p);
nsCID prompt_cid = MYCOMPONENT_CID;
res = comp_reg->RegisterFactory(prompt_cid,
"MyComponent",
"#mozilla.org/mycomp;1",
prompt_factory);
Those lines are copied from GeckoEngine::Init(), using the same mechanism to register PromptService, etc. The code compiles well and testapp.exe is running as expected.
I put javascript test as below :
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
const cid = "#mozilla.org/mycomp;1";
obj = Components.classes[cid].createInstance();
alert(typeof obj);
// bind the instance we just created to our interface
alert(Components.interfaces.nsIMyComponent);
obj = obj.QueryInterface(Components.interfaces.nsIMyComponent);
} catch (err) {
alert(err);
return;
}
and get the following exception:
Could not convert JavaScript argument arg 0 [nsISupport.QueryInterface]
The first alert says "object", so the line
Components.classes[cid].createInstance()
is returning the created instance.
The second alert says "undefined", so the interface nsIMyComponent is not recognized by XULRunner.
How to dynamically registering nsIMyComponent interface in wxWebConnect environment ?
Thx
I'm not sure what is happening here. The first thing I would check is that your component is scriptable (I assume it is, since the demo you copy from is). The next thing I would check is whether you can instantiate other, standard XULRunner components and get their interface (try something like "alert('Components.interfaces.nsIFile');" - at least in my version of wxWebConnect this shows an alert box with string "nsIFile".
Also, I think it would be worth checking the Error Console to make sure there are no errors or warnings reported. A magic string to do that (in Javascript) is:
window.open('chrome://global/content/console.xul', '', 'chrome,dialog=no,toolbar,resizable');