If (false) may be useful

Can you be friend with this kind of dead code? In this particular subject my opinion is slightly different from the general. I can agree that in the ideal programming world there is no need to use dead code, but in reality there are situations when it's good to consider this solution as appropriate.

Secret behind 0.999... = 1

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Wikipedia: 0.999...

Searching a solution we often forget about the problem behind it. I'm familiar with the wrong focusing on 'how' instead on 'why', and what's more I've seen people doing the same mistakes as well. For example, let's just look at law regulations as synonym of complication paired with uncleanness. However, I'll drop that subject and introduce the similar problem occurring in maths. Do not expect any great proof, because I'll do that to explain it as simple as possible.

Przeglądarki kontra bezpieczeństwo

Czyż Internet Explorer nie służy do przeglądania internetu z twojego komputera i vice versa?

Mogliśmy jakiś czas temu zaobserwować miły gest ze strony Mozilli wspierający osoby które chcą zwiększyć bezpieczeństwo ich produktu (patrz: Refresh of the Mozilla Security Bug Bounty Program). Zaciekawiony tymże faktem poszperałem więcej w poszukiwaniu informacji o bezpieczeństwie naszych przeglądarek...

Ciekawostką jest raport firmy CERT z 2005r (ich pierwszy nawiasem mówiąc) - jednakże jego jakość jest wątpliwa i bardziej tu pasuje nazwa 'zestawienie'. Taki współczynnik jak ( Liczba luk / Popularność ) jest nie tyle nietrafiony co wręcz błędny. Otóż im większa szansa zysku z odkrytej luki tym częściej i szybciej zostanie ona wykorzystana, a w internecie ilość przekłada się przecież w bezpośredni sposób na zysk. Tak więc, moim zdaniem, powinno być raczej ( Liczba luk * Popularność ). Ten sam mechanizm działa też w drugą stronę: firmy mające małą liczbę użytkowników są znacznie mniej podatne na ataki.

Informatyk zawodem wysokiego ryzyka?

Kolejny post dotyczący naszego Polskiego "zaścianka". A mianowicie chciałbym napomknąć jak wygląda egzystencja nas informatyków w kontekście przepisów prawnych oraz strachu przed naszymi umiejętnościami.

Javarsovia 2010 z drugiej ręki

Odczucia

• Z niecierpliwością czekam na następną Javarsovie, co moim zdaniem samo z siebie świadczy o tym jak bardzo byłem zadowolony z uczestnictwa.
• Afterparty także pobiło moje oczekiwania, tylko prelegentów na niej trochę brakowało.
• Dodatkowo byłem pod wrażeniem liczby uczestników.
• Na pewno niewybaczalnym jest fakt, że nie wygrałem Asusa .
• Tak wiele się działo, że brakowało mi czasu, aby dokładnie zapoznać się ze stoiskami sponsorów.

GUI in GridBagLayout

Basically, I do not like GridBagLayaout, but from my point of view it's the most effective way to build and maintain GUI. So before explaining my point of view, let's eliminate other path.

Forwarding exceptions as language potential

Each of Java programmer knows how exhausting a handing exception can be. So sooner on later he/she founds the situation when he/she exactly knows that he/she is handling the exception that will never occur. Some thoughts about this can be found here.

The '!' logical-complement operator (fixed)

It's high time to clear doubts about: The '!' logical-complement operator. With little help of someone who can express himself more clearly, subject should be easier to follow.

Some time ago I used to know all operators priorities in C++, using a minimal number of braces resulted with a quite compact code in logical cases. It was really easy to read that again, but only for me, what I did not see as a problem. When I started to work on the same code with others there were no turn back and I had to make conditions more readable...

The logical-complement operator !

Maybe I'm weird but I really do not like syntax for this operator.

Now time it's like:

if (!person.getThinkingModel().isThinking()){...}

I would personally prefer:

if (person.getThinkingModel().!isThinking()){...}

I would do same about instanceof to allow:

if (obj !instanceof Person){...}

Work around:
Would be nice to see both methods generated isThinking() as well as isNotThinking() instead of one in that case. Problem in this solutions involve setters which should be duplicated as well, and mostly 'Not' version should call traditional with simple negation, which increases stack traces.

if (person.getThinkingModel().isNotThinking()){...}

This way have one more advantage. When you write in more than one language you can worry less about operators priority.

Use yours own judgement, which is easier to read and write.

Little confusion about Generics

Lets consider some class used for collecting References. It requires little work but there is way to do not determine Reference type to early. So lets observe consequences of this action.

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;

/**
 * Collects {@link Reference}-s
 */
public class ReferenceCollector<Ref extends Reference</* ? extends */ Type>, Type>
    implements Iterable<Reference<? extends Type>> { ... }


This class will allow given code to compile:

ReferenceCollector<WeakReference<String>, ?> rc1 = null;

ReferenceCollector<WeakReference<String>, ? extends Object> rc2 = null;

On the other hand reversing Type arguments will be not allowed:

ReferenceCollector<WeakReference<? extends Object>, String> rc2 = null;

This mean that nesting is count more then arguments order, what more it's all about compatibility not as I would expect equality of types. Probably I just need read rest of JLS when I'll have free time to get idea why '?' is allowed as second generic argument.

I just killed Eclipse

I like enum-s more than most people do.

They are really nice to use and synchronization-safe. But as I found, they have their limits as well.

After generating 1,8Mb Java code for one enum Eclipse dying after most try of refactorization ;), Java was not happy at all about it as well with error:

The code for the static initializer is exceeding the 65535 bytes limit

Enhanced while statement proposal

OVERVIEW

FEATURE SUMMARY:
Enhanced while statement allow to iterate through iterator.

MAJOR ADVANTAGE:
People will stop working around for-each loop.

MAJOR BENEFIT(s):
Allow to easy express operation on iterator(s), and iterating over non linear Iterators.

MAJOR DISADVANTAGE:
Automatic loop over Iterator my be problem for some peoples.

ALTERNATIVES:
Using while loop.

'forget' keyword proposal

OVERVIEW

FEATURE SUMMARY:
'forget' keyword allows to erase variable from current context, or it means that field should not be used.

MAJOR ADVANTAGE:
This change makes language be more WYSIWYG.

MAJOR BENEFIT(s):

• It makes people be able to erase 'variable' from current context, while now it's:
  • impossible for final variables (only by comments),
  • impossible for arguments (for not final Object we can assign null),
  • impossible for fields.
  • local fields need more or 'less' artificial blocks (two lines wasted and one indent level).
• Declaring that variable should not be used, or does not contain valid information for this scope (at current time) will be possible.
• Code quality does not fall so drastically after we leave it, comparing to '=null', 'only comments' or 'weird blocks'.

MAJOR DISADVANTAGE:
New keyword == Someone can have declared method/field/variable named 'forget'.

ALTERNATIVES:
It's already listed.

'final' without explicit type proposal

OVERVIEW

FEATURE SUMMARY:

MAJOR ADVANTAGE:
It allows people to concentrate on logic during operating on heavy generics and to use values which are more intuitive for them than variables.

MAJOR BENEFIT(s):

• It allows to avoid duplicating unnecessarily types of declaration.
• It increase a concentration on 'what I've got' than on 'what type is that' (we decrease size by one to obtain last element index, not because we can do this = it's int), while for variables we still keep concentrate on: 'what type is that' / 'what I can put there'.
• Editing existing code to get some value from method chain is easier.
• That method can be itself multi-thread with this, but it's a far future.
• Using of Generics is easier.

MAJOR DISADVANTAGE:

• Certainly, some people will overuse this solution.
• Consider operator is easier to read.
• It might be a problem if a person does not know how to give proper names for values.

ALTERNATIVES:
Normal variables.

Glue classes proposal 0.9

OVERVIEW

FEATURE SUMMARY:

Glue classes allow to link utils direct with objects.

MAJOR ADVANTAGE:

Forgotten functionality can be not such big deal now.

MAJOR BENEFIT(s):

• New functions can be easy localized (critically important while introduce new peoples into project).
• Security: glue class do not see anything protected.
• Light binding new functions with existing classes.
• Number of used classes reduction.
• Allow to assign methods and functions(static methods) to arrays, classes, interfaces, …
• It's proof against same method occurs in class and delegator as well like in two delegators.
• Allow to link gained(.jar) logic with new one, witch is impossible before final developer implements his classes.
• Allow to project compact interfaces and do not worry about additional logic.

MAJOR DISADVANTAGE:
Do not know any ;) sorry.

ALTERNATIVES:
Utils classes, more work on project, duplicated code...

Return 'this' proposal

GENESIS

It's a simplified 'This' type problem, which seems to be too much complicated as for now and need more analyses. Construction is designed not to interact with possibility that 'This' type will be introduced.

OVERVIEW

FEATURE SUMMARY:
It allows the method to return reference to 'this' object.

MAJOR ADVANTAGE:
Simplification of return this; statement.
'void' can be easy replaced with 'this'.

MAJOR BENEFIT(s): It would prevent NullPointerException, and make some 'builder' like interfaces look really clear and simple.

MAJOR DISADVANTAGE:
Returned value cannot be changed while inheritance.

ALTERNATIVES:
Self-bounded generics, This type.

Read-only & Partial arrays proposal

Instrukcje

Tworzenie tablic do odczytu pozwoliło by zwiększyć szybkość jak i bezpieczeństwo pisanych programów. Była by to zwykła tablica tworzona na podstawie już istniejącej bez możliwości modyfikacji jej stanu.

Tablice częściowe tworzone na tablicach do odczytu pomogły by zmniejszyć ryzyko popełnienia błędu dostępu do niewłaściwego obszaru tablicy oraz zmniejszyło by zużycie pamięci.

Glue classes proposal beta

OVERVIEW

Notice that it's beta specification: it's not described in full details, half validated (translation), and it's provided for you to pre-analyse. I still need some time to provide syntax which fully supports generics. Multi-glue classes are under consideration as well, but this may occur to be to complex to handle by any earth living programmer.

FEATURE SUMMARY:
Glue classes allow to link utils direct with objects.

MAJOR ADVANTAGE:
Forgotten functionality can be not such big deal now.

MAJOR BENEFIT(s):

• New functions can be easy localised (critically important while introduce new peoples into project).
• Security: glue class do not see anything protected.
• Light binding new functions with existing classes.
• Number of used classes reduction.
• Allow to assign methods and functions(static methods) to arrays, classes, interfaces, …
• It's proof against same method occurs in class and delegator as well like in two delegators.
• Allow to link gained(.jar) logic with new one, witch is impossible before final developer implements his classes.
• Allow to project compact interfaces and do not worry about additional logic.

MAJOR DISADVANTAGE:
Do not know any ;) sorry.

ALTERNATIVES:
Utils classes.

Consider operator proposal

OVERVIEW

FEATURE SUMMARY:
Consider operator extends language with full value support and assign value to name and return it.

MAJOR ADVANTAGE:
It introduces natural division in variables and values.

It makes language to be more natural for human and generics easier to use.

MAJOR BENEFIT(s):

• If we need to get a value, we can do that quite simple (without splitting expression or duplicating code).
• Decrease number of potential bugs (value cannot be assigned).
• It can help in splitting code to proper parts; nowdays, we need to declare variable regardless we need it or not (or make it final).
• Decrease size of unnecessary code.
• Method can be itself multi-thread with this, but it's far future.

MAJOR DISADVANTAGE:
Possibility to be unclear at start.

ALTERNATIVES:
Some time 'final' variables can be used, but it's more like for-each, life is better with it.

Delegation proposal

OVERVIEW

FEATURE SUMMARY:
This change allow to delegate methods, interfaces and classes.

MAJOR ADVANTAGE:
It would be a first step for programmers to have something instead of inheritance, allowing to write better code.

MAJOR BENEFITS:
Java looks incomplete without something so base as delegating. Others are:

• Code more immune for changes(if interface changes, there will be not so much to change, or I would say, changes will be on the right place, but not on all projects)
• Decreasing costs of code modification.
• Explicit defining MethodModifiers

MAJOR DISADVANTAGE:
Changes cost.

ALTERNATIVES:
It's nothing that cannot be implemented in a simple way, but this change does not increase delegation complex, unreadablity, and costs of support with each method.