I am trying to debug a simple Java application which is using Lambda Expression. I am not able to debug Lambda Expression using normal Eclipse debugger.
It's late answer but hope it is useful for someone.
I use this https://stackoverflow.com/a/24542150/10605477 but sometimes when code is a bit messy or I can't get data I just break the code and insert peek.
protected Optional<Name> get(String username) {
return profileDao.getProfiles()
.stream()
.filter(profile ->
profile.getUserName().equals(username))
.peek(data -> System.out.println(data))
.findFirst();
}
You can transform the expressions into statements.
List<String> list = new ArrayList<>();
// expression
boolean allMatch1 = list.stream().allMatch(s -> s.contains("Hello"));
// statement
boolean allMatch2 = list.stream().allMatch(s -> {
return s.contains("Hello");
});
You can now set the break-point on the return s.contains("Hello"); line
Related
In the non reactive world the following code snippet is nothing special:
interface Enhancer {
Result enhance(Result result);
}
Result result = Result.empty();
result = fooEnhancer.enhance(result);
result = barEnhancer.enhance(result);
result = bazEnhancer.enhance(result);
There are three different Enhancer implementations taking a Result instance, enhancing it and returning the enhanced result. Let's assume the order of the enhancer calls matters.
Now what if these methods are replaced by reactive variants returning a Flux<Result>? Because the methods depend on the result(s) of the preceding method, we cannot use combineLatest here.
A possible solution could be:
Flux.just(Result.empty())
.switchMap(result -> first(result)
.switchMap(result -> second(result)
.switchMap(result -> third(result))))
.subscribe(result -> doSomethingWith(result));
Note that the switchMap calls are nested. As we are only interested in the final result, we let switchMap switch to the next flux as soon as new events are emitted in preceding fluxes.
Now let's try to do it with a dynamic number of fluxes. Non reactive (without fluxes), this would again be nothing special:
List<Enhancer> enhancers = <ordered list of different Enhancer impls>;
Result result = Result.empty();
for (Enhancer enhancer : enhancers) {
result = enhancer.enhance(result);
}
But how can I generalize the above reactive example with three fluxes to deal with an arbitrary number of fluxes?
I found a solution using recursion:
#FunctionalInterface
interface FluxProvider {
Flux<Result> get(Result result);
}
// recursive method creating the final Flux
private Flux<Result> cascadingSwitchMap(Result input, List<FluxProvider> fluxProviders, int idx) {
if (idx < fluxProviders.size()) {
return fluxProviders.get(idx).get(input).switchMap(result -> cascadingSwitchMap(result, fluxProviders, idx + 1));
}
return Flux.just(input);
}
// code using the recursive method
List<FluxProvider> fluxProviders = new ArrayList<>();
fluxProviders.add(fooEnhancer::enhance);
fluxProviders.add(barEnhancer::enhance);
fluxProviders.add(bazEnhancer::enhance);
cascadingSwitchMap(Result.empty(), fluxProviders, 0)
.subscribe(result -> doSomethingWith(result));
But maybe there is a more elegant solution using an operator/feature of project-reactor. Does anybody know such a feature? In fact, the requirement doesn't seem to be such an unusual one, is it?
switchMap feels inappropriate here. If you have a List<Enhancer> by the time the Flux pipeline is declared, why not apply a logic close to what you had in imperative style:
List<Enhancer> enhancers = <ordered list of different Enhancer impls>;
Mono<Result> resultMono = Mono.just(Result.empty)
for (Enhancer enhancer : enhancers) {
resultMono = resultMono.map(enhancer::enhance); //previousValue -> enhancer.enhance(previousValue)
}
return resultMono;
That can even be performed later at subscription time for even more dynamic resolution of the enhancers by wrapping the whole code above in a Mono.defer(() -> {...}) block.
I did a template string operation class which can operate std::string and MFC CString.
It workes fine on the Debug version.
It does work on the Release version.
By my investigation, I found that at least one useful function is optimized.
checkChars is optimized which is supposed to be called in the split. (checkChars isn't being called.)
static bool checkChars(const TCHARTYPE& c, const TCHARTYPE* chrs)
{
for ( ;*chrs ;chrs++)
{
if (c == *chrs)
{
return true;
}
}
return false;
}
void split(const TSTRING& s, vector<TSTRING>& v, const TCHARTYPE* separator, bool bKeepEmptyParts = false)
{
...
//here at() is called, but checkChars isn't
if (checkChars(at(s, i), separator))
...
}
The VS Optimization is
Maximize Speed (/O2)
. I found use
Custom
can prevent the Optimization of my useful function.
But I want to know why, and I don't want to change the project settings, Can I just modify my code to make it work?
Edit:
After a long time, I realized that the real problem is not Optimization, is that "at()" fuction doesn't return the expected char reference. TSTRING here is CString MFC which does not return a TCHAR reference. The compiler found this would not work, so "optimized" it.
is there any way to disable compiler optimisation for a specific line of code?
http://msdn.microsoft.com/en-us/library/chh3fb0k.aspx
#pragma optimize( "", off )
.
.
.
#pragma optimize( "", on )
I want to read the <param> values of custom plugin
I could not find answer on the internet, what I found was:
https://github.com/firebreath/FireBreath/blob/master/src/NpapiCore/NpapiPlugin.cpp#L76
I see params are stored in pluginMain->setParams(paramList);
Can you point how can I access this paramList later? or pluginMain
Is there pluginMain->getParams()? I could not find reference
Nor I could locate the source for setParams().
The question is, how do I get that parameters from PluginWindowXXX or FB::NpapiPluginXXX ?
I exported m_npHost to PluginWindowXXX, set breakpoint in it with gdb but still no success.
All I can think of was:
(gdb) p ((FB::Npapi::NpapiBrowserHost)this->m_npHost)->GetValue
$17 = {NPError (const FB::Npapi::NpapiBrowserHost * const, NPNVariable, void *)} 0x7fe435adeff8 <FB::Npapi::NpapiBrowserHost::GetValue(NPNVariable, void*) const>
Obviously what I do is wrong but I am stuck,
I am passing this host from NpapiPluginX11.cpp
pluginWin->setHost(m_npHost);
taxilian's answer is the most correct one as always but I'll give a try. I'm reading params in my MyPluginAPI constructor.
MyPluginAPI::MyPluginAPI(const MyPluginPtr& plugin, const FB::BrowserHostPtr& host) : m_plugin(plugin), m_host(host)
{
string settings; //<param name="settings" value="{'foo':'bar'}">
settings = plugin->getParam("settings");
}
Inside your PluginCore-derived class, you can use either the getParam method or the getParamVariant method.
From the FireBreath Source:
boost::optional<std::string> PluginCore::getParam(const std::string& key) {
boost::optional<std::string> rval;
FB::VariantMap::const_iterator fnd = m_params.find(key.c_str());
if (fnd != m_params.end())
rval.reset(fnd->second.convert_cast<std::string>());
return rval;
}
FB::variant FB::PluginCore::getParamVariant( const std::string& key )
{
FB::VariantMap::const_iterator fnd = m_params.find(key.c_str());
if (fnd != m_params.end())
return fnd->second;
return FB::variant();
}
So if it's for sure a string (which it pretty much is, unless it starts with on, in which case it might have been converted to a referenced function), you can use:
boost::optional<std::string> mystr = getParam("mystr");
if (mystr) {
call_fn_with_string(*mystr);
}
Alternately, you can get it as a variant and convert it:
FB::variant mystrVal = getParamVariant("mystr");
try {
call_fn_with_string(mystrVal.convert_cast<std::string>());
} catch (FB::bad_variant_cast &err) {
// What to do if the cast to string fails
}
I want to know whether is it possible to reject numeric phrases or numeric values while indexing or searching in Lucene.net.
For example (this is one line),
Hi all my no is 4756396
Now, when I index or search it should reject the numeric value 4756396 to be indexed or searched. I tried making a custom stop word list with 1, 2, 3, 4, 5, 6, etc, but I guess it will only ignore if a single number will appears.
You can copy the StandardAnalyzer and customize the grammar (simple JFlex stuff) to reject number tokens. If you do that, you'll need to port back the analyzer to Java since JFlex will generate java code, tho you could give it a try with C# Flex.
You could also write a TokenFilter that scans tokens one by one and rejects them if they are numbers. If you wanna filter only whole numbers and still retain numbers that are for example separate by hyphens, the filter could simply attempt a double.TryParse() and if it fails you accept the Token. A more robust and customizable solution would still use a lexical parser.
Edit:
Heres a quick sample of what I mean, with a little main method that shows how to use it. In this I used a TryParse() to filter out tokens, if it were for a more complex production system I'd use a lexical parser system. (take a look at C# Flex for that)
public class NumericFilter : TokenFilter
{
private ITermAttribute termAtt ;
public NumericFilter(TokenStream tokStream)
: base(tokStream)
{
termAtt = AddAttribute<ITermAttribute>();
}
public override bool IncrementToken()
{
while (base.input.IncrementToken())
{
string term = termAtt.Term;
double res ;
if(double.TryParse(term, out res))
{
// skip this token
continue;
}
// accept this token
return true;
}
// no more token in the stream
return false;
}
}
static void Main(string[] args)
{
RAMDirectory dir = new RAMDirectory();
IndexWriter iw = new IndexWriter(dir, new KeywordAnalyzer(), IndexWriter.MaxFieldLength.UNLIMITED);
Document d = new Document();
Field f = new Field("text", "", Field.Store.YES, Field.Index.ANALYZED);
d.Add(f);
// use our Filter here
f.SetTokenStream(new NumericFilter(new LowerCaseFilter(new WhitespaceTokenizer(new StringReader("I have 300 dollars")))));
iw.AddDocument(d);
iw.Commit();
IndexReader reader = iw.GetReader();
// print all terms in the text field
TermEnum terms = reader.Terms(new Term("text", ""));
do
{
Console.WriteLine(terms.Term.Text);
}
while (terms.Next());
reader.Dispose();
iw.Dispose();
Console.ReadLine();
Environment.Exit(42);
}
Consider the below program
private static bool CheckFactorPresent(List<FactorReturn> factorReturnCol)
{
bool IsPresent = true;
StringBuilder sb = new StringBuilder();
//Get the exposure names from Exposure list.
//Since this will remain same , so it has been done outside the loop
List<string> lstExposureName = (from item in Exposures
select item.ExposureName).ToList<string>();
foreach (FactorReturn fr in factorReturnCol)
{
//Build the factor names from the ReturnCollection dictionary
List<string> lstFactorNames = fr.ReturnCollection.Keys.ToList<string>();
//Check if all the Factor Names are present in ExposureName list
List<string> result = lstFactorNames.Except(lstExposureName).ToList();
if (result.Count() > 0)
{
result.ForEach(i =>
{
IsPresent = false;
sb.AppendLine("Factor" + i + "is not present for week no: " + fr.WeekNo.ToString());
});
}
}
return IsPresent;
}
Basically I am checking if all the FactorNames[lstFactorNames] are present in
ExposureNames[lstExposureName] list by using lstFactorNames.Except(lstExposureName).
And then by using the Count() function(if count() > 0), I am writing the error
messages to the String Builder(sb)
I am sure that someone can definitely write a better implementation than the one presented.
And I am looking forward for the same to learn something new from that program.
I am using c#3.0 and dotnet framework 3.5
Thanks
Save for some naming convention issues, I'd say that looks fine (for what I can figure out without seeing the rest of the code, or the purpose in the effort. The naming conventions though, need some work. A sporadic mix of ntnHungarian, PascalCase, camelCase, and abbrv is a little disorienting. Try just naming your local variables camelCase exclusively and things will look a lot better. Best of luck to you - things are looking good so far!
- EDIT -
Also, you can clean up the iteration at the end by just running a simple foreach:
...
foreach (var except in result)
{
isPresent = false;
builder.AppendFormat("Factor{0} is not present for week no: {1}\r\n", except, fr.WeekNo);
}
...