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  • When is type testing OK?

    - by svidgen
    Assuming a language with some inherent type safety (e.g., not JavaScript): Given a method that accepts a SuperType, we know that in most cases wherein we might be tempted to perform type testing to pick an action: public void DoSomethingTo(SuperType o) { if (o isa SubTypeA) { o.doSomethingA() } else { o.doSomethingB(); } } We should usually, if not always, create a single, overridable method on the SuperType and do this: public void DoSomethingTo(SuperType o) { o.doSomething(); } ... wherein each subtype is given its own doSomething() implementation. The rest of our application can then be appropriately ignorant of whether any given SuperType is really a SubTypeA or a SubTypeB. Wonderful. But, we're still given is a-like operations in most, if not all, type-safe languages. And that seems suggests a potential need for explicit type testing. So, in what situations, if any, should we or must we perform explicit type testing? Forgive my absent mindedness or lack of creativity. I know I've done it before; but, it was honestly so long ago I can't remember if what I did was good! And in recent memory, I don't think I've encountered a need to test types outside my cowboy JavaScript.

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  • Scheduling of jobs in the presence of constraints in Java

    - by Asgard
    I want to know how to implement a solution to this problem: A task is performed by running, by more people, some basic jobs with known duration in time units (days, months, etc..). The execution of the jobs could lead to the existence of time constraints: a job, for example, can not start if it is not over another (or others) and so on. I want to design and build an application to check the correctness of jobs activities and to propose a schedule of jobs, if any, which is respectful of the constraints. Input must provide the jobs and associated constraints. The expected output is the scheduling of jobs. The specification of an elementary job consists of the pair <jobs-id, duration> A constraint is expressed by means of a quintuple of the type <S/E, id-job1, B/A, S/E, id-job2> the beginning (S) or the end (E) of a jobs Id-job1, must take place before (B) / after (A) of the beginning (S) / end (E) of the Id-job2. If there are no dependencies between some jobs, then jobs can be done before, in parallel. As a simple example, consider the input: jobs jobs(0, 3) jobs(1, 4) jobs(2, 5) jobs(3, 3) jobs(4, 3) constraints constraints(S, 1, A, E, 0) constraints(S, 4, A, E, 2) Possible output: t 0 1 2 3 4 0 * - * * - 1 * - * * - 2 * - * * - 3 * - * * - 4 - * * - - 5 - * * - - 6 - * - - * 7 - * - - * 8 - * - - * 9 - - - - * How to code an efficient java scheduler(avoiding the intense backtracking if is possible) to manage the jobs with these constraints, as described??? I have seen a discussion on a thread in a forum where an user seems has solved the problem easily, but He haven't given enough details to the users to compile a working project(I'm noob), and I'm interested to know an effective implementation of the solution (without using external libraries). If someone help me, I'll give to him a very good feedback ;)

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  • Best way to enforce inter-table constraints inside database

    - by FerranB
    I looking for the best way to check for inter-table constraints an step forward of foreing keys. For instance, to check if a date child record value is between a range date on two parent rows columns. For instance: Parent table ID DATE_MIN DATE_MAX ----- ---------- ---------- 1 01/01/2009 01/03/2009 ... Child table PARENT_ID DATE ---------- ---------- 1 01/02/2009 1 01/12/2009 <--- HAVE TO FAIL! ... I see two approaches: Create materialized views on-commit as shown in this article (or other equivalent on other RDBMS). Use stored-procedures and triggers. Any other approach? Which is the best option? UPDATE: The motivation of this question is not about "putting the constraints on database or on application". I think this is a tired question and anyone does the way she loves. And, I'm sorry for detractors, I'm developing with constraints on database. From here, the question is "which is the best option to manage inter-table constraints on database?". I'm added "inside database" on the question title. UPDATE 2: Some one added the "oracle" tag. Of course materialized views are oracle-tools but I'm interested on any option regardless it's on oracle or others RDBMSs.

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  • How to program for constraints/rules

    - by Gaurav
    First the background, during interviews in the past, many times I have been asked to design some or other variation of card game as programming puzzle, and I have tried to design it in OO way, but I have never been satisfied with my solutions. However it was not until recently that I realized that I had been approaching the problem from the wrong direction. Specifically I was trying to solve the problem by modeling individual card as an object. Problem with this is individual cards don't have any non-trivial intrinsic behavior and therefore are not suitable (or primary) candidate as objects. What is interesting and important about cards are rules and constraints, such as there could be only four suits, or only thirteen cards in each suit. Of course, then there are any number of rules for games. So my questions are Are there any idioms/constructs/patterns to program for rules & constraints. How many in 1 can be applied in conjunction with OO paradigm.

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  • Type Casting variables in PHP: Is there a practical example?

    - by Stephen
    PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which the variable is used. Love it or hate it, PHP re-casts variables on-the-fly. So, the following code is valid: $var = "10"; $value = 10 + $var; var_dump($value); // int(20) PHP also alows you to explicitly cast a variable, like so: $var = "10"; $value = 10 + $var; $value = (string)$value; var_dump($value); // string(2) "20" That's all cool... but, for the life of me, I cannot conceive of a practical reason for doing this. I don't have a problem with strong typing in languages that support it, like Java. That's fine, and I completely understand it. Also, I'm aware of—and fully understand the usefulness of—type hinting in function parameters. The problem I have with type casting is explained by the above quote. If PHP can swap types at-will, it can do so even after you force cast a type; and it can do so on-the-fly when you need a certain type in an operation. That makes the following valid: $var = "10"; $value = (int)$var; $value = $value . ' TaDa!'; var_dump($value); // string(8) "10 TaDa!" So what's the point? Can anyone show me a practical application or example of type casting—one that would fail if type casting were not involved? I ask this here instead of SO because I figure practicality is too subjective. Edit in response to Chris' comment Take this theoretical example of a world where user-defined type casting makes sense in PHP: You force cast variable $foo as int -- (int)$foo. You attempt to store a string value in the variable $foo. PHP throws an exception!! <--- That would make sense. Suddenly the reason for user defined type casting exists! The fact that PHP will switch things around as needed makes the point of user defined type casting vague. For example, the following two code samples are equivalent: // example 1 $foo = 0; $foo = (string)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; // example 2 $foo = 0; $foo = (int)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo;

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  • Type Casting variables in PHP: Is there a practical example?

    - by Stephen
    PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which the variable is used. Love it or hate it, PHP re-casts variables on-the-fly. So, the following code is valid: $var = "10"; $value = 10 + $var; var_dump($value); // int(20) PHP also alows you to explicitly cast a variable, like so: $var = "10"; $value = 10 + $var; $value = (string)$value; var_dump($value); // string(2) "20" That's all cool... but, for the life of me, I cannot conceive of a practical reason for doing this. I don't have a problem with strong typing in languages that support it, like Java. That's fine, and I completely understand it. Also, I'm aware of—and fully understand the usefulness of—type hinting in function parameters. The problem I have with type casting is explained by the above quote. If PHP can swap types at-will, it can do so even after you force cast a type; and it can do so on-the-fly when you need a certain type in an operation. That makes the following valid: $var = "10"; $value = (int)$var; $value = $value . ' TaDa!'; var_dump($value); // string(8) "10 TaDa!" So what's the point? Can anyone show me a practical application or example of type casting—one that would fail if type casting were not involved? I ask this here instead of SO because I figure practicality is too subjective. Edit in response to Chris' comment Take this theoretical example of a world where user-defined type casting makes sense in PHP: You force cast variable $foo as int -- (int)$foo. You attempt to store a string value in the variable $foo. PHP throws an exception!! <--- That would make sense. Suddenly the reason for user defined type casting exists! The fact that PHP will switch things around as needed makes the point of user defined type casting vague. For example, the following two code samples are equivalent: // example 1 $foo = 0; $foo = (string)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; // example 2 $foo = 0; $foo = (int)$foo; $foo = '# of Reasons for the programmer to type cast $foo as a string: ' . $foo; UPDATE Guess who found himself using typecasting in a practical environment? Yours Truly. The requirement was to display money values on a website for a restaurant menu. The design of the site required that trailing zeros be trimmed, so that the display looked something like the following: Menu Item 1 .............. $ 4 Menu Item 2 .............. $ 7.5 Menu Item 3 .............. $ 3 The best way I found to do that wast to cast the variable as a float: $price = '7.50'; // a string from the database layer. echo 'Menu Item 2 .............. $ ' . (float)$price; PHP trims the float's trailing zeros, and then recasts the float as a string for concatenation.

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  • SQL Server Constraints Across Tables

    - by chama
    I have a SQL Server database with an Apartment table (which has columns FloorNum and BuildingID) and an ApartmentBuilding table (with column NumFloors). Is there any way to set up a constraint (using the SQL Server UI) to check that Apartment.FloorNum is greater than ApartmentBuilding.NumFloors? I tried this: FloorNum > ApartmentBuilding.NumFloors but now I realize that I somehow have to join the columns on the BuildingID, but I have no idea how to do that within a constraint. Thanks for your help!

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  • eventmachine on debian fails install via rubygems

    - by Max
    this has been killing me for the last 5 hours. I don't seem to be able to get eventmachine running on my debian box. here this output: $ gem install thin Building native extensions. This could take a while... ERROR: Error installing thin: ERROR: Failed to build gem native extension. /home/eventhub/.rvm/rubies/ruby-1.9.3-p125/bin/ruby extconf.rb checking for rb_trap_immediate in ruby.h,rubysig.h... no checking for rb_thread_blocking_region()... yes checking for inotify_init() in sys/inotify.h... yes checking for writev() in sys/uio.h... yes checking for rb_wait_for_single_fd()... yes checking for rb_enable_interrupt()... yes checking for rb_time_new()... yes checking for sys/event.h... no checking for epoll_create() in sys/epoll.h... yes creating Makefile make compiling kb.cpp cc1plus: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but not for C++ cc1plus: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but not for C++ In file included from project.h:149, from kb.cpp:20: binder.h:35: warning: type qualifiers ignored on function return type In file included from project.h:150, from kb.cpp:20: em.h:84: warning: type qualifiers ignored on function return type em.h:85: warning: type qualifiers ignored on function return type em.h:86: warning: type qualifiers ignored on function return type em.h:88: warning: type qualifiers ignored on function return type em.h:89: warning: type qualifiers ignored on function return type em.h:90: warning: type qualifiers ignored on function return type em.h:91: warning: type qualifiers ignored on function return type em.h:93: warning: type qualifiers ignored on function return type em.h:99: warning: type qualifiers ignored on function return type em.h:116: warning: type qualifiers ignored on function return type em.h:125: warning: type qualifiers ignored on function return type In file included from project.h:154, from kb.cpp:20: eventmachine.h:46: warning: type qualifiers ignored on function return type eventmachine.h:47: warning: type qualifiers ignored on function return type eventmachine.h:48: warning: type qualifiers ignored on function return type eventmachine.h:50: warning: type qualifiers ignored on function return type eventmachine.h:65: warning: type qualifiers ignored on function return type eventmachine.h:66: warning: type qualifiers ignored on function return type eventmachine.h:67: warning: type qualifiers ignored on function return type eventmachine.h:68: warning: type qualifiers ignored on function return type In file included from project.h:154, from kb.cpp:20: eventmachine.h:103: warning: type qualifiers ignored on function return type eventmachine.h:105: warning: type qualifiers ignored on function return type eventmachine.h:108: warning: type qualifiers ignored on function return type compiling rubymain.cpp cc1plus: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but not for C++ cc1plus: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but not for C++ In file included from project.h:149, from rubymain.cpp:20: binder.h:35: warning: type qualifiers ignored on function return type In file included from project.h:150, from rubymain.cpp:20: em.h:84: warning: type qualifiers ignored on function return type em.h:85: warning: type qualifiers ignored on function return type em.h:86: warning: type qualifiers ignored on function return type em.h:88: warning: type qualifiers ignored on function return type em.h:89: warning: type qualifiers ignored on function return type em.h:90: warning: type qualifiers ignored on function return type em.h:91: warning: type qualifiers ignored on function return type em.h:93: warning: type qualifiers ignored on function return type em.h:99: warning: type qualifiers ignored on function return type em.h:116: warning: type qualifiers ignored on function return type em.h:125: warning: type qualifiers ignored on function return type In file included from project.h:154, from rubymain.cpp:20: eventmachine.h:46: warning: type qualifiers ignored on function return type eventmachine.h:47: warning: type qualifiers ignored on function return type eventmachine.h:48: warning: type qualifiers ignored on function return type eventmachine.h:50: warning: type qualifiers ignored on function return type eventmachine.h:65: warning: type qualifiers ignored on function return type eventmachine.h:66: warning: type qualifiers ignored on function return type eventmachine.h:67: warning: type qualifiers ignored on function return type eventmachine.h:68: warning: type qualifiers ignored on function return type In file included from project.h:154, from rubymain.cpp:20: eventmachine.h:103: warning: type qualifiers ignored on function return type eventmachine.h:105: warning: type qualifiers ignored on function return type eventmachine.h:108: warning: type qualifiers ignored on function return type compiling ssl.cpp cc1plus: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but not for C++ cc1plus: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but not for C++ In file included from project.h:149, from ssl.cpp:23: binder.h:35: warning: type qualifiers ignored on function return type In file included from project.h:150, from ssl.cpp:23: em.h:84: warning: type qualifiers ignored on function return type em.h:85: warning: type qualifiers ignored on function return type em.h:86: warning: type qualifiers ignored on function return type em.h:88: warning: type qualifiers ignored on function return type em.h:89: warning: type qualifiers ignored on function return type em.h:90: warning: type qualifiers ignored on function return type em.h:91: warning: type qualifiers ignored on function return type em.h:93: warning: type qualifiers ignored on function return type em.h:99: warning: type qualifiers ignored on function return type em.h:116: warning: type qualifiers ignored on function return type em.h:125: warning: type qualifiers ignored on function return type In file included from project.h:154, from ssl.cpp:23: eventmachine.h:46: warning: type qualifiers ignored on function return type eventmachine.h:47: warning: type qualifiers ignored on function return type eventmachine.h:48: warning: type qualifiers ignored on function return type eventmachine.h:50: warning: type qualifiers ignored on function return type eventmachine.h:65: warning: type qualifiers ignored on function return type eventmachine.h:66: warning: type qualifiers ignored on function return type eventmachine.h:67: warning: type qualifiers ignored on function return type eventmachine.h:68: warning: type qualifiers ignored on function return type In file included from project.h:154, from ssl.cpp:23: eventmachine.h:103: warning: type qualifiers ignored on function return type eventmachine.h:105: warning: type qualifiers ignored on function return type eventmachine.h:108: warning: type qualifiers ignored on function return type compiling cmain.cpp cc1plus: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but not for C++ cc1plus: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but not for C++ In file included from project.h:149, from cmain.cpp:20: binder.h:35: warning: type qualifiers ignored on function return type In file included from project.h:150, from cmain.cpp:20: em.h:84: warning: type qualifiers ignored on function return type em.h:85: warning: type qualifiers ignored on function return type em.h:86: warning: type qualifiers ignored on function return type em.h:88: warning: type qualifiers ignored on function return type em.h:89: warning: type qualifiers ignored on function return type em.h:90: warning: type qualifiers ignored on function return type em.h:91: warning: type qualifiers ignored on function return type em.h:93: warning: type qualifiers ignored on function return type em.h:99: warning: type qualifiers ignored on function return type em.h:116: warning: type qualifiers ignored on function return type em.h:125: warning: type qualifiers ignored on function return type In file included from project.h:154, from cmain.cpp:20: eventmachine.h:46: warning: type qualifiers ignored on function return type eventmachine.h:47: warning: type qualifiers ignored on function return type eventmachine.h:48: warning: type qualifiers ignored on function return type eventmachine.h:50: warning: type qualifiers ignored on function return type eventmachine.h:65: warning: type qualifiers ignored on function return type eventmachine.h:66: warning: type qualifiers ignored on function return type eventmachine.h:67: warning: type qualifiers ignored on function return type eventmachine.h:68: warning: type qualifiers ignored on function return type In file included from project.h:154, from cmain.cpp:20: eventmachine.h:103: warning: type qualifiers ignored on function return type eventmachine.h:105: warning: type qualifiers ignored on function return type eventmachine.h:108: warning: type qualifiers ignored on function return type cmain.cpp:96: warning: type qualifiers ignored on function return type cmain.cpp:107: warning: type qualifiers ignored on function return type cmain.cpp:117: warning: type qualifiers ignored on function return type cmain.cpp:127: warning: type qualifiers ignored on function return type cmain.cpp:269: warning: type qualifiers ignored on function return type cmain.cpp:279: warning: type qualifiers ignored on function return type cmain.cpp:289: warning: type qualifiers ignored on function return type cmain.cpp:299: warning: type qualifiers ignored on function return type cmain.cpp:309: warning: type qualifiers ignored on function return type cmain.cpp:329: warning: type qualifiers ignored on function return type cmain.cpp:678: warning: type qualifiers ignored on function return type compiling em.cpp cc1plus: warning: command line option "-Wdeclaration-after-statement" is valid for C/ObjC but not for C++ cc1plus: warning: command line option "-Wimplicit-function-declaration" is valid for C/ObjC but not for C++ In file included from project.h:149, from em.cpp:23: binder.h:35: warning: type qualifiers ignored on function return type In file included from project.h:150, from em.cpp:23: em.h:84: warning: type qualifiers ignored on function return type em.h:85: warning: type qualifiers ignored on function return type em.h:86: warning: type qualifiers ignored on function return type em.h:88: warning: type qualifiers ignored on function return type em.h:89: warning: type qualifiers ignored on function return type em.h:90: warning: type qualifiers ignored on function return type em.h:91: warning: type qualifiers ignored on function return type em.h:93: warning: type qualifiers ignored on function return type em.h:99: warning: type qualifiers ignored on function return type em.h:116: warning: type qualifiers ignored on function return type em.h:125: warning: type qualifiers ignored on function return type In file included from project.h:154, from em.cpp:23: eventmachine.h:46: warning: type qualifiers ignored on function return type eventmachine.h:47: warning: type qualifiers ignored on function return type eventmachine.h:48: warning: type qualifiers ignored on function return type eventmachine.h:50: warning: type qualifiers ignored on function return type eventmachine.h:65: warning: type qualifiers ignored on function return type eventmachine.h:66: warning: type qualifiers ignored on function return type eventmachine.h:67: warning: type qualifiers ignored on function return type eventmachine.h:68: warning: type qualifiers ignored on function return type In file included from project.h:154, from em.cpp:23: eventmachine.h:103: warning: type qualifiers ignored on function return type eventmachine.h:105: warning: type qualifiers ignored on function return type eventmachine.h:108: warning: type qualifiers ignored on function return type em.cpp: In member function 'bool EventMachine_t::_RunEpollOnce()': em.cpp:578: warning: 'int rb_thread_select(int, fd_set*, fd_set*, fd_set*, timeval*)' is deprecated (declared at /home/eventhub/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/intern.h:379) em.cpp:578: warning: 'int rb_thread_select(int, fd_set*, fd_set*, fd_set*, timeval*)' is deprecated (declared at /home/eventhub/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/intern.h:379) em.cpp: In member function 'bool EventMachine_t::_RunSelectOnce()': em.cpp:974: warning: 'int rb_thread_select(int, fd_set*, fd_set*, fd_set*, timeval*)' is deprecated (declared at /home/eventhub/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/intern.h:379) em.cpp:974: warning: 'int rb_thread_select(int, fd_set*, fd_set*, fd_set*, timeval*)' is deprecated (declared at /home/eventhub/.rvm/rubies/ruby-1.9.3-p125/include/ruby-1.9.1/ruby/intern.h:379) em.cpp: At global scope: em.cpp:1057: warning: type qualifiers ignored on function return type em.cpp:1079: warning: type qualifiers ignored on function return type em.cpp:1265: warning: type qualifiers ignored on function return type em.cpp:1338: warning: type qualifiers ignored on function return type em.cpp:1510: warning: type qualifiers ignored on function return type em.cpp:1593: warning: type qualifiers ignored on function return type em.cpp:1856: warning: type qualifiers ignored on function return type em.cpp:1982: warning: type qualifiers ignored on function return type em.cpp:2046: warning: type qualifiers ignored on function return type em.cpp:2070: warning: type qualifiers ignored on function return type em.cpp:2142: warning: type qualifiers ignored on function return type em.cpp:2361: fatal error: error writing to /tmp/ccdlOK0T.s: No space left on device compilation terminated. make: *** [em.o] Error 1 Gem files will remain installed in /home/eventhub/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-1.0.1 for inspection. Results logged to /home/eventhub/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-1.0.1/ext/gem_make.out Any thoughts? I read a lot of different ways to solve this issue, but none of them worked. Thanks

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  • Type checking and recursive types (Writing the Y combinator in Haskell/Ocaml)

    - by beta
    When explaining the Y combinator in the context of Haskell, it's usually noted that the straight-forward implementation won't type-check in Haskell because of its recursive type. For example, from Rosettacode [1]: The obvious definition of the Y combinator in Haskell canot be used because it contains an infinite recursive type (a = a -> b). Defining a data type (Mu) allows this recursion to be broken. newtype Mu a = Roll { unroll :: Mu a -> a } fix :: (a -> a) -> a fix = \f -> (\x -> f (unroll x x)) $ Roll (\x -> f (unroll x x)) And indeed, the “obvious” definition does not type check: ?> let fix f g = (\x -> \a -> f (x x) a) (\x -> \a -> f (x x) a) g <interactive>:10:33: Occurs check: cannot construct the infinite type: t2 = t2 -> t0 -> t1 Expected type: t2 -> t0 -> t1 Actual type: (t2 -> t0 -> t1) -> t0 -> t1 In the first argument of `x', namely `x' In the first argument of `f', namely `(x x)' In the expression: f (x x) a <interactive>:10:57: Occurs check: cannot construct the infinite type: t2 = t2 -> t0 -> t1 In the first argument of `x', namely `x' In the first argument of `f', namely `(x x)' In the expression: f (x x) a (0.01 secs, 1033328 bytes) The same limitation exists in Ocaml: utop # let fix f g = (fun x a -> f (x x) a) (fun x a -> f (x x) a) g;; Error: This expression has type 'a -> 'b but an expression was expected of type 'a The type variable 'a occurs inside 'a -> 'b However, in Ocaml, one can allow recursive types by passing in the -rectypes switch: -rectypes Allow arbitrary recursive types during type-checking. By default, only recursive types where the recursion goes through an object type are supported. By using -rectypes, everything works: utop # let fix f g = (fun x a -> f (x x) a) (fun x a -> f (x x) a) g;; val fix : (('a -> 'b) -> 'a -> 'b) -> 'a -> 'b = <fun> utop # let fact_improver partial n = if n = 0 then 1 else n*partial (n-1);; val fact_improver : (int -> int) -> int -> int = <fun> utop # (fix fact_improver) 5;; - : int = 120 Being curious about type systems and type inference, this raises some questions I'm still not able to answer. First, how does the type checker come up with the type t2 = t2 -> t0 -> t1? Having come up with that type, I guess the problem is that the type (t2) refers to itself on the right side? Second, and perhaps most interesting, what is the reason for the Haskell/Ocaml type systems to disallow this? I guess there is a good reason since Ocaml also will not allow it by default even if it can deal with recursive types if given the -rectypes switch. If these are really big topics, I'd appreciate pointers to relevant literature. [1] http://rosettacode.org/wiki/Y_combinator#Haskell

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  • How to allow bind in app armor?

    - by WitchCraft
    Question: I did setup bind9 as described here: http://ubuntuforums.org/showthread.php?p=12149576#post12149576 Now I have a little problem with apparmor: If I switch it off, it works. If apparmor runs, it doesn't work, and I get the following dmesg output: [ 23.809767] type=1400 audit(1344097913.519:11): apparmor="STATUS" operation="profile_replace" name="/sbin/dhclient" pid=1540 comm="apparmor_parser" [ 23.811537] type=1400 audit(1344097913.519:12): apparmor="STATUS" operation="profile_replace" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=1540 comm="apparmor_parser" [ 23.812514] type=1400 audit(1344097913.523:13): apparmor="STATUS" operation="profile_replace" name="/usr/lib/connman/scripts/dhclient-script" pid=1540 comm="apparmor_parser" [ 23.821999] type=1400 audit(1344097913.531:14): apparmor="STATUS" operation="profile_load" name="/usr/sbin/mysqld" pid=1544 comm="apparmor_parser" [ 23.845085] type=1400 audit(1344097913.555:15): apparmor="STATUS" operation="profile_load" name="/usr/sbin/libvirtd" pid=1543 comm="apparmor_parser" [ 23.849051] type=1400 audit(1344097913.559:16): apparmor="STATUS" operation="profile_load" name="/usr/sbin/named" pid=1545 comm="apparmor_parser" [ 23.849509] type=1400 audit(1344097913.559:17): apparmor="STATUS" operation="profile_load" name="/usr/lib/libvirt/virt-aa-helper" pid=1542 comm="apparmor_parser" [ 23.851597] type=1400 audit(1344097913.559:18): apparmor="STATUS" operation="profile_load" name="/usr/sbin/tcpdump" pid=1547 comm="apparmor_parser" [ 24.415193] type=1400 audit(1344097914.123:19): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=1625 comm="apparmor_parser" [ 24.738631] ip_tables: (C) 2000-2006 Netfilter Core Team [ 25.005242] nf_conntrack version 0.5.0 (16384 buckets, 65536 max) [ 25.187939] ADDRCONF(NETDEV_UP): virbr0: link is not ready [ 26.004282] Ebtables v2.0 registered [ 26.068783] ip6_tables: (C) 2000-2006 Netfilter Core Team [ 28.158848] postgres (1900): /proc/1900/oom_adj is deprecated, please use /proc/1900/oom_score_adj instead. [ 29.840079] xenbr0: no IPv6 routers present [ 31.502916] type=1400 audit(1344097919.088:20): apparmor="DENIED" operation="mknod" parent=1984 profile="/usr/sbin/named" name="/var/log/query.log" pid=1989 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 34.336141] xenbr0: port 1(eth0) entering forwarding state [ 38.424359] Event-channel device installed. [ 38.853077] XENBUS: Unable to read cpu state [ 38.854215] XENBUS: Unable to read cpu state [ 38.855231] XENBUS: Unable to read cpu state [ 38.858891] XENBUS: Unable to read cpu state [ 47.411497] device vif1.0 entered promiscuous mode [ 47.429245] ADDRCONF(NETDEV_UP): vif1.0: link is not ready [ 49.366219] virbr0: port 1(vif1.0) entering disabled state [ 49.366705] virbr0: port 1(vif1.0) entering disabled state [ 49.368873] virbr0: mixed no checksumming and other settings. [ 97.273028] type=1400 audit(1344097984.861:21): apparmor="DENIED" operation="mknod" parent=3076 profile="/usr/sbin/named" name="/var/log/query.log" pid=3078 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 277.790627] type=1400 audit(1344098165.377:22): apparmor="DENIED" operation="mknod" parent=3384 profile="/usr/sbin/named" name="/var/log/query.log" pid=3389 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 287.812986] type=1400 audit(1344098175.401:23): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/root/tmp-gjnX0c0dDa" pid=3400 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 287.818466] type=1400 audit(1344098175.405:24): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/root/tmp-CpOtH52qU5" pid=3400 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 323.166228] type=1400 audit(1344098210.753:25): apparmor="DENIED" operation="mknod" parent=3422 profile="/usr/sbin/named" name="/var/log/query.log" pid=3427 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 386.512586] type=1400 audit(1344098274.101:26): apparmor="DENIED" operation="mknod" parent=3456 profile="/usr/sbin/named" name="/var/log/query.log" pid=3459 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 808.549049] type=1400 audit(1344098696.137:27): apparmor="DENIED" operation="mknod" parent=3872 profile="/usr/sbin/named" name="/var/log/query.log" pid=3877 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 894.671081] type=1400 audit(1344098782.257:28): apparmor="DENIED" operation="mknod" parent=3922 profile="/usr/sbin/named" name="/var/log/query.log" pid=3927 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 968.514669] type=1400 audit(1344098856.101:29): apparmor="DENIED" operation="mknod" parent=3978 profile="/usr/sbin/named" name="/var/log/query.log" pid=3983 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1021.814582] type=1400 audit(1344098909.401:30): apparmor="DENIED" operation="mknod" parent=4010 profile="/usr/sbin/named" name="/var/log/query.log" pid=4012 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1063.856633] type=1400 audit(1344098951.445:31): apparmor="DENIED" operation="mknod" parent=4041 profile="/usr/sbin/named" name="/var/log/query.log" pid=4043 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1085.404001] type=1400 audit(1344098972.989:32): apparmor="DENIED" operation="mknod" parent=4072 profile="/usr/sbin/named" name="/var/log/query.log" pid=4077 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1108.207402] type=1400 audit(1344098995.793:33): apparmor="DENIED" operation="mknod" parent=4102 profile="/usr/sbin/named" name="/var/log/query.log" pid=4107 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1156.947189] type=1400 audit(1344099044.533:34): apparmor="DENIED" operation="mknod" parent=4134 profile="/usr/sbin/named" name="/var/log/query.log" pid=4136 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1166.768005] type=1400 audit(1344099054.353:35): apparmor="DENIED" operation="mknod" parent=4150 profile="/usr/sbin/named" name="/var/log/query.log" pid=4155 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1168.873385] type=1400 audit(1344099056.461:36): apparmor="DENIED" operation="mknod" parent=4162 profile="/usr/sbin/named" name="/var/log/query.log" pid=4167 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1181.558946] type=1400 audit(1344099069.145:37): apparmor="DENIED" operation="mknod" parent=4177 profile="/usr/sbin/named" name="/var/log/query.log" pid=4182 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 1199.349265] type=1400 audit(1344099086.937:38): apparmor="DENIED" operation="mknod" parent=4191 profile="/usr/sbin/named" name="/var/log/query.log" pid=4196 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 1296.805604] type=1400 audit(1344099184.393:39): apparmor="DENIED" operation="mknod" parent=4232 profile="/usr/sbin/named" name="/var/log/query.log" pid=4237 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1317.730568] type=1400 audit(1344099205.317:40): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-nuBes0IXwi" pid=4251 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1317.730744] type=1400 audit(1344099205.317:41): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-ZDJA06ZOkU" pid=4252 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1365.072687] type=1400 audit(1344099252.661:42): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-EnsuYUrGOC" pid=4290 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1365.074520] type=1400 audit(1344099252.661:43): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-LVCnpWOStP" pid=4287 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1380.336984] type=1400 audit(1344099267.925:44): apparmor="DENIED" operation="mknod" parent=4617 profile="/usr/sbin/named" name="/var/log/query.log" pid=4622 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1437.924534] type=1400 audit(1344099325.513:45): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-Uyf1dHIZUU" pid=4648 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1437.924626] type=1400 audit(1344099325.513:46): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/tmp-OABXWclII3" pid=4647 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1526.334959] type=1400 audit(1344099413.921:47): apparmor="DENIED" operation="mknod" parent=4749 profile="/usr/sbin/named" name="/var/log/query.log" pid=4754 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 1601.292548] type=1400 audit(1344099488.881:48): apparmor="DENIED" operation="mknod" parent=4835 profile="/usr/sbin/named" name="/var/log/query.log" pid=4840 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 1639.543733] type=1400 audit(1344099527.129:49): apparmor="DENIED" operation="mknod" parent=4905 profile="/usr/sbin/named" name="/var/log/query.log" pid=4907 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1916.381179] type=1400 audit(1344099803.969:50): apparmor="DENIED" operation="mknod" parent=4959 profile="/usr/sbin/named" name="/var/log/query.log" pid=4961 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 1940.816898] type=1400 audit(1344099828.405:51): apparmor="DENIED" operation="mknod" parent=4991 profile="/usr/sbin/named" name="/var/log/query.log" pid=4996 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 2043.010898] type=1400 audit(1344099930.597:52): apparmor="DENIED" operation="mknod" parent=5048 profile="/usr/sbin/named" name="/var/log/query.log" pid=5053 comm="named" requested_mask="c" denied_mask="c" fsuid=107 ouid=107 [ 2084.956230] type=1400 audit(1344099972.545:53): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/var/log/tmp-XYgr33RqUt" pid=5069 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 2084.959120] type=1400 audit(1344099972.545:54): apparmor="DENIED" operation="mknod" parent=3325 profile="/usr/sbin/named" name="/var/log/tmp-vO24RHwL14" pid=5066 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 2088.169500] type=1400 audit(1344099975.757:55): apparmor="DENIED" operation="mknod" parent=5076 profile="/usr/sbin/named" name="/var/log/query.log" pid=5078 comm="named" requested_mask="c" denied_mask="c" fsuid=0 ouid=0 [ 2165.625096] type=1400 audit(1344100053.213:56): apparmor="STATUS" operation="profile_remove" name="/sbin/dhclient" pid=5124 comm="apparmor" [ 2165.625401] type=1400 audit(1344100053.213:57): apparmor="STATUS" operation="profile_remove" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=5124 comm="apparmor" [ 2165.625608] type=1400 audit(1344100053.213:58): apparmor="STATUS" operation="profile_remove" name="/usr/lib/connman/scripts/dhclient-script" pid=5124 comm="apparmor" [ 2165.625782] type=1400 audit(1344100053.213:59): apparmor="STATUS" operation="profile_remove" name="/usr/lib/libvirt/virt-aa-helper" pid=5124 comm="apparmor" [ 2165.625931] type=1400 audit(1344100053.213:60): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/libvirtd" pid=5124 comm="apparmor" [ 2165.626057] type=1400 audit(1344100053.213:61): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/mysqld" pid=5124 comm="apparmor" [ 2165.626181] type=1400 audit(1344100053.213:62): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/named" pid=5124 comm="apparmor" [ 2165.626319] type=1400 audit(1344100053.213:63): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/tcpdump" pid=5124 comm="apparmor" [ 3709.583927] type=1400 audit(1344101597.169:64): apparmor="STATUS" operation="profile_load" name="/usr/sbin/libvirtd" pid=7484 comm="apparmor_parser" [ 3709.839895] type=1400 audit(1344101597.425:65): apparmor="STATUS" operation="profile_load" name="/usr/sbin/mysqld" pid=7485 comm="apparmor_parser" [ 3710.008892] type=1400 audit(1344101597.597:66): apparmor="STATUS" operation="profile_load" name="/usr/lib/libvirt/virt-aa-helper" pid=7483 comm="apparmor_parser" [ 3710.545232] type=1400 audit(1344101598.133:67): apparmor="STATUS" operation="profile_load" name="/usr/sbin/named" pid=7486 comm="apparmor_parser" [ 3710.655600] type=1400 audit(1344101598.241:68): apparmor="STATUS" operation="profile_load" name="/sbin/dhclient" pid=7481 comm="apparmor_parser" [ 3710.656013] type=1400 audit(1344101598.241:69): apparmor="STATUS" operation="profile_load" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=7481 comm="apparmor_parser" [ 3710.656786] type=1400 audit(1344101598.245:70): apparmor="STATUS" operation="profile_load" name="/usr/lib/connman/scripts/dhclient-script" pid=7481 comm="apparmor_parser" [ 3710.832624] type=1400 audit(1344101598.421:71): apparmor="STATUS" operation="profile_load" name="/usr/sbin/tcpdump" pid=7488 comm="apparmor_parser" [ 3717.573123] type=1400 audit(1344101605.161:72): apparmor="DENIED" operation="open" parent=7505 profile="/usr/sbin/named" name="/var/log/query.log" pid=7510 comm="named" requested_mask="ac" denied_mask="ac" fsuid=107 ouid=0 [ 3743.667808] type=1400 audit(1344101631.253:73): apparmor="STATUS" operation="profile_remove" name="/sbin/dhclient" pid=7552 comm="apparmor" [ 3743.668338] type=1400 audit(1344101631.257:74): apparmor="STATUS" operation="profile_remove" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=7552 comm="apparmor" [ 3743.668625] type=1400 audit(1344101631.257:75): apparmor="STATUS" operation="profile_remove" name="/usr/lib/connman/scripts/dhclient-script" pid=7552 comm="apparmor" [ 3743.668834] type=1400 audit(1344101631.257:76): apparmor="STATUS" operation="profile_remove" name="/usr/lib/libvirt/virt-aa-helper" pid=7552 comm="apparmor" [ 3743.668991] type=1400 audit(1344101631.257:77): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/libvirtd" pid=7552 comm="apparmor" [ 3743.669127] type=1400 audit(1344101631.257:78): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/mysqld" pid=7552 comm="apparmor" [ 3743.669282] type=1400 audit(1344101631.257:79): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/named" pid=7552 comm="apparmor" [ 3743.669520] type=1400 audit(1344101631.257:80): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/tcpdump" pid=7552 comm="apparmor" [ 3873.572336] type=1400 audit(1344101761.161:81): apparmor="STATUS" operation="profile_load" name="/usr/sbin/libvirtd" pid=7722 comm="apparmor_parser" [ 3873.826209] type=1400 audit(1344101761.413:82): apparmor="STATUS" operation="profile_load" name="/usr/sbin/mysqld" pid=7723 comm="apparmor_parser" [ 3873.988181] type=1400 audit(1344101761.577:83): apparmor="STATUS" operation="profile_load" name="/usr/lib/libvirt/virt-aa-helper" pid=7721 comm="apparmor_parser" [ 3874.520305] type=1400 audit(1344101762.109:84): apparmor="STATUS" operation="profile_load" name="/sbin/dhclient" pid=7719 comm="apparmor_parser" [ 3874.520736] type=1400 audit(1344101762.109:85): apparmor="STATUS" operation="profile_load" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=7719 comm="apparmor_parser" [ 3874.521000] type=1400 audit(1344101762.109:86): apparmor="STATUS" operation="profile_load" name="/usr/lib/connman/scripts/dhclient-script" pid=7719 comm="apparmor_parser" [ 3874.528878] type=1400 audit(1344101762.117:87): apparmor="STATUS" operation="profile_load" name="/usr/sbin/named" pid=7724 comm="apparmor_parser" [ 3874.930712] type=1400 audit(1344101762.517:88): apparmor="STATUS" operation="profile_load" name="/usr/sbin/tcpdump" pid=7726 comm="apparmor_parser" [ 3971.744599] type=1400 audit(1344101859.333:89): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/libvirtd" pid=7899 comm="apparmor_parser" [ 3972.009857] type=1400 audit(1344101859.597:90): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=7900 comm="apparmor_parser" [ 3972.165297] type=1400 audit(1344101859.753:91): apparmor="STATUS" operation="profile_replace" name="/usr/lib/libvirt/virt-aa-helper" pid=7898 comm="apparmor_parser" [ 3972.587766] type=1400 audit(1344101860.173:92): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/named" pid=7901 comm="apparmor_parser" [ 3972.847189] type=1400 audit(1344101860.433:93): apparmor="STATUS" operation="profile_replace" name="/sbin/dhclient" pid=7896 comm="apparmor_parser" [ 3972.847705] type=1400 audit(1344101860.433:94): apparmor="STATUS" operation="profile_replace" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=7896 comm="apparmor_parser" [ 3972.848150] type=1400 audit(1344101860.433:95): apparmor="STATUS" operation="profile_replace" name="/usr/lib/connman/scripts/dhclient-script" pid=7896 comm="apparmor_parser" [ 3973.147889] type=1400 audit(1344101860.733:96): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/tcpdump" pid=7903 comm="apparmor_parser" [ 3988.863999] type=1400 audit(1344101876.449:97): apparmor="DENIED" operation="open" parent=7939 profile="/usr/sbin/named" name="/var/log/query.log" pid=7944 comm="named" requested_mask="ac" denied_mask="ac" fsuid=107 ouid=0 [ 4025.826132] type=1400 audit(1344101913.413:98): apparmor="STATUS" operation="profile_remove" name="/sbin/dhclient" pid=7975 comm="apparmor" [ 4025.826627] type=1400 audit(1344101913.413:99): apparmor="STATUS" operation="profile_remove" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=7975 comm="apparmor" [ 4025.826861] type=1400 audit(1344101913.413:100): apparmor="STATUS" operation="profile_remove" name="/usr/lib/connman/scripts/dhclient-script" pid=7975 comm="apparmor" [ 4025.827059] type=1400 audit(1344101913.413:101): apparmor="STATUS" operation="profile_remove" name="/usr/lib/libvirt/virt-aa-helper" pid=7975 comm="apparmor" [ 4025.827214] type=1400 audit(1344101913.413:102): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/libvirtd" pid=7975 comm="apparmor" [ 4025.827352] type=1400 audit(1344101913.413:103): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/mysqld" pid=7975 comm="apparmor" [ 4025.827485] type=1400 audit(1344101913.413:104): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/named" pid=7975 comm="apparmor" [ 4025.827624] type=1400 audit(1344101913.413:105): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/tcpdump" pid=7975 comm="apparmor" [ 4027.862198] type=1400 audit(1344101915.449:106): apparmor="STATUS" operation="profile_load" name="/usr/sbin/libvirtd" pid=8090 comm="apparmor_parser" [ 4039.500920] audit_printk_skb: 21 callbacks suppressed [ 4039.500932] type=1400 audit(1344101927.089:114): apparmor="STATUS" operation="profile_remove" name="/sbin/dhclient" pid=8114 comm="apparmor" [ 4039.501413] type=1400 audit(1344101927.089:115): apparmor="STATUS" operation="profile_remove" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=8114 comm="apparmor" [ 4039.501672] type=1400 audit(1344101927.089:116): apparmor="STATUS" operation="profile_remove" name="/usr/lib/connman/scripts/dhclient-script" pid=8114 comm="apparmor" [ 4039.501861] type=1400 audit(1344101927.089:117): apparmor="STATUS" operation="profile_remove" name="/usr/lib/libvirt/virt-aa-helper" pid=8114 comm="apparmor" [ 4039.502033] type=1400 audit(1344101927.089:118): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/libvirtd" pid=8114 comm="apparmor" [ 4039.502170] type=1400 audit(1344101927.089:119): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/mysqld" pid=8114 comm="apparmor" [ 4039.502305] type=1400 audit(1344101927.089:120): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/named" pid=8114 comm="apparmor" [ 4039.502442] type=1400 audit(1344101927.089:121): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/tcpdump" pid=8114 comm="apparmor" [ 4041.425405] type=1400 audit(1344101929.013:122): apparmor="STATUS" operation="profile_load" name="/usr/lib/libvirt/virt-aa-helper" pid=8240 comm="apparmor_parser" [ 4041.425952] type=1400 audit(1344101929.013:123): apparmor="STATUS" operation="profile_load" name="/sbin/dhclient" pid=8238 comm="apparmor_parser" [ 4058.910390] audit_printk_skb: 18 callbacks suppressed [ 4058.910401] type=1400 audit(1344101946.497:130): apparmor="STATUS" operation="profile_remove" name="/sbin/dhclient" pid=8264 comm="apparmor" [ 4058.910757] type=1400 audit(1344101946.497:131): apparmor="STATUS" operation="profile_remove" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=8264 comm="apparmor" [ 4058.910969] type=1400 audit(1344101946.497:132): apparmor="STATUS" operation="profile_remove" name="/usr/lib/connman/scripts/dhclient-script" pid=8264 comm="apparmor" [ 4058.911185] type=1400 audit(1344101946.497:133): apparmor="STATUS" operation="profile_remove" name="/usr/lib/libvirt/virt-aa-helper" pid=8264 comm="apparmor" [ 4058.911335] type=1400 audit(1344101946.497:134): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/libvirtd" pid=8264 comm="apparmor" [ 4058.911595] type=1400 audit(1344101946.497:135): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/mysqld" pid=8264 comm="apparmor" [ 4058.911856] type=1400 audit(1344101946.497:136): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/named" pid=8264 comm="apparmor" [ 4058.912001] type=1400 audit(1344101946.497:137): apparmor="STATUS" operation="profile_remove" name="/usr/sbin/tcpdump" pid=8264 comm="apparmor" [ 4060.266700] type=1400 audit(1344101947.853:138): apparmor="STATUS" operation="profile_load" name="/sbin/dhclient" pid=8391 comm="apparmor_parser" [ 4060.268356] type=1400 audit(1344101947.857:139): apparmor="STATUS" operation="profile_load" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=8391 comm="apparmor_parser" [ 5909.432749] audit_printk_skb: 18 callbacks suppressed [ 5909.432759] type=1400 audit(1344103797.021:146): apparmor="DENIED" operation="open" parent=8800 profile="/usr/sbin/named" name="/var/log/query.log" pid=8805 comm="named" requested_mask="ac" denied_mask="ac" fsuid=107 ouid=0 root@zotac:~# What can I do that it still works and I don't have to disable apparmor ?

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  • What are the safety benefits of a type system?

    - by vandros526
    In Javascript: The Good Parts by Douglas Crockford, he mentions in his inheritance chapter, "The other benefit of classical inheritance is that it includes the specification of a system of types. This mostly frees the programmer from having to write explicit casting operations, which is a very good thing because when casting, the safety benefits of a type system are lost." So first of all, what actually is safety? protection against data corruption, or hackers, or system malfunctions, etc? What are the safety benefits of a type system? What makes a type system different that allows it to provide these safety benefits?

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  • Converting Generic Type into reference type after checking its type using GetType(). How ?

    - by Shantanu Gupta
    i am trying to call a function that is defined in a class RFIDeas_Wrapper(dll being used). But when i checked for type of reader and after that i used it to call function it shows me error Cannot convert type T to RFIDeas_Wrapper. EDIT private List<string> GetTagCollection<T>(T Reader) { TagCollection = new List<string>(); if (Reader.GetType() == typeof(RFIDeas_Wrapper)) { ((RFIDeas_Wrapper)Reader).OpenDevice(); // here Reader is of type RFIDeas_Wrapper //, but i m not able to convert Reader into its datatype. string Tag_Id = ((RFIDeas_Wrapper)Reader).TagID(); //Adds Valid Tag Ids into the collection if(Tag_Id!="0") TagCollection.Add(Tag_Id); } else if (Reader.GetType() == typeof(AlienReader)) TagCollection = ((AlienReader)Reader).TagCollection; return TagCollection; } ((RFIDeas_Wrapper)Reader).OpenDevice(); , ((AlienReader)Reader).TagCollection; I want this line to be executed without any issue. As Reader will always be of the type i m specifying. How to make compiler understand the same thing.

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  • Java JTextPane JScrollPane Display Issue

    - by ikurtz
    The following class implements a chatGUI. When it runs okay the screen looks like this: Fine ChatGUI The problem is very often when i enter text of large length ie. 50 - 100 chars the gui goes crazy. the chat history box shrinks as shown in this image. Any ideas regarding what is causing this? Thank you. package Sartre.Connect4; import javax.swing.*; import java.net.*; import java.awt.*; import java.awt.event.*; import javax.swing.text.StyledDocument; import javax.swing.text.Style; import javax.swing.text.StyleConstants; import javax.swing.text.BadLocationException; import java.io.BufferedOutputStream; import javax.swing.text.html.HTMLEditorKit; import java.io.FileOutputStream; import java.io.IOException; import java.io.FileNotFoundException; import javax.swing.filechooser.FileNameExtensionFilter; import javax.swing.JFileChooser; /** * Chat form class * @author iAmjad */ public class ChatGUI extends JDialog implements ActionListener { /** * Used to hold chat history data */ private JTextPane textPaneHistory = new JTextPane(); /** * provides scrolling to chat history pane */ private JScrollPane scrollPaneHistory = new JScrollPane(textPaneHistory); /** * used to input local message to chat history */ private JTextPane textPaneHome = new JTextPane(); /** * Provides scrolling to local chat pane */ private JScrollPane scrollPaneHomeText = new JScrollPane(textPaneHome); /** * JLabel acting as a statusbar */ private JLabel statusBar = new JLabel("Ready"); /** * Button to clear chat history pane */ private JButton JBClear = new JButton("Clear"); /** * Button to save chat history pane */ private JButton JBSave = new JButton("Save"); /** * Holds contentPane */ private Container containerPane; /** * Layout GridBagLayout manager */ private GridBagLayout gridBagLayout = new GridBagLayout(); /** * GridBagConstraints */ private GridBagConstraints constraints = new GridBagConstraints(); /** * Constructor for ChatGUI */ public ChatGUI(){ setTitle("Chat"); // set up dialog icon URL url = getClass().getResource("Resources/SartreIcon.jpg"); ImageIcon imageIcon = new ImageIcon(url); Image image = imageIcon.getImage(); this.setIconImage(image); this.setAlwaysOnTop(true); setLocationRelativeTo(this.getParent()); //////////////// End icon and placement ///////////////////////// // Get pane and set layout manager containerPane = getContentPane(); containerPane.setLayout(gridBagLayout); ///////////////////////////////////////////////////////////// //////////////// Begin Chat History ////////////////////////////// textPaneHistory.setToolTipText("Chat History Window"); textPaneHistory.setEditable(false); textPaneHistory.setPreferredSize(new Dimension(350,250)); scrollPaneHistory.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); scrollPaneHistory.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER); // fill Chat History GridBagConstraints constraints.gridx = 0; constraints.gridy = 0; constraints.gridwidth = 10; constraints.gridheight = 10; constraints.weightx = 100; constraints.weighty = 100; constraints.fill = GridBagConstraints.BOTH; constraints.anchor = GridBagConstraints.CENTER; constraints.insets = new Insets(10,10,10,10); constraints.ipadx = 0; constraints.ipady = 0; gridBagLayout.setConstraints(scrollPaneHistory, constraints); // add to the pane containerPane.add(scrollPaneHistory); /////////////////////////////// End Chat History /////////////////////// ///////////////////////// Begin Home Chat ////////////////////////////// textPaneHome.setToolTipText("Home Chat Message Window"); textPaneHome.setPreferredSize(new Dimension(200,50)); textPaneHome.addKeyListener(new MyKeyAdapter()); scrollPaneHomeText.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); scrollPaneHomeText.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER); // fill Chat History GridBagConstraints constraints.gridx = 0; constraints.gridy = 10; constraints.gridwidth = 6; constraints.gridheight = 1; constraints.weightx = 100; constraints.weighty = 100; constraints.fill = GridBagConstraints.BOTH; constraints.anchor = GridBagConstraints.CENTER; constraints.insets = new Insets(10,10,10,10); constraints.ipadx = 0; constraints.ipady = 0; gridBagLayout.setConstraints(scrollPaneHomeText, constraints); // add to the pane containerPane.add(scrollPaneHomeText); ////////////////////////// End Home Chat ///////////////////////// ///////////////////////Begin Clear Chat History //////////////////////// JBClear.setToolTipText("Clear Chat History"); // fill Chat History GridBagConstraints constraints.gridx = 6; constraints.gridy = 10; constraints.gridwidth = 2; constraints.gridheight = 1; constraints.weightx = 100; constraints.weighty = 100; constraints.fill = GridBagConstraints.BOTH; constraints.anchor = GridBagConstraints.CENTER; constraints.insets = new Insets(10,10,10,10); constraints.ipadx = 0; constraints.ipady = 0; gridBagLayout.setConstraints(JBClear, constraints); JBClear.addActionListener(this); // add to the pane containerPane.add(JBClear); ///////////////// End Clear Chat History //////////////////////// /////////////// Begin Save Chat History ////////////////////////// JBSave.setToolTipText("Save Chat History"); constraints.gridx = 8; constraints.gridy = 10; constraints.gridwidth = 2; constraints.gridheight = 1; constraints.weightx = 100; constraints.weighty = 100; constraints.fill = GridBagConstraints.BOTH; constraints.anchor = GridBagConstraints.CENTER; constraints.insets = new Insets(10,10,10,10); constraints.ipadx = 0; constraints.ipady = 0; gridBagLayout.setConstraints(JBSave, constraints); JBSave.addActionListener(this); // add to the pane containerPane.add(JBSave); ///////////////////// End Save Chat History ///////////////////// /////////////////// Begin Status Bar ///////////////////////////// constraints.gridx = 0; constraints.gridy = 11; constraints.gridwidth = 10; constraints.gridheight = 1; constraints.weightx = 100; constraints.weighty = 50; constraints.fill = GridBagConstraints.BOTH; constraints.anchor = GridBagConstraints.CENTER; constraints.insets = new Insets(0,10,5,0); constraints.ipadx = 0; constraints.ipady = 0; gridBagLayout.setConstraints(statusBar, constraints); // add to the pane containerPane.add(statusBar); ////////////// End Status Bar //////////////////////////// // set resizable to false this.setResizable(false); // pack the GUI pack(); } /** * Deals with necessary menu click events * @param event */ public void actionPerformed(ActionEvent event) { Object source = event.getSource(); // Process Clear button event if (source == JBClear){ textPaneHistory.setText(null); statusBar.setText("Chat History Cleared"); } // Process Save button event if (source == JBSave){ // process only if there is data in history pane if (textPaneHistory.getText().length() > 0){ // process location where to save the chat history file JFileChooser chooser = new JFileChooser(); chooser.setMultiSelectionEnabled(false); chooser.setAcceptAllFileFilterUsed(false); FileNameExtensionFilter filter = new FileNameExtensionFilter("HTML Documents", "htm", "html"); chooser.setFileFilter(filter); int option = chooser.showSaveDialog(ChatGUI.this); if (option == JFileChooser.APPROVE_OPTION) { // Set up document to be parsed as HTML StyledDocument doc = (StyledDocument)textPaneHistory.getDocument(); HTMLEditorKit kit = new HTMLEditorKit(); BufferedOutputStream out; try { // add final file name and extension String filePath = chooser.getSelectedFile().getAbsoluteFile() + ".html"; out = new BufferedOutputStream(new FileOutputStream(filePath)); // write out the HTML document kit.write(out, doc, doc.getStartPosition().getOffset(), doc.getLength()); } catch (FileNotFoundException e) { JOptionPane.showMessageDialog(ChatGUI.this, "Application will now close. \n A restart may cure the error!\n\n" + e.getMessage(), "Fatal Error", JOptionPane.WARNING_MESSAGE, null); System.exit(2); } catch (IOException e){ JOptionPane.showMessageDialog(ChatGUI.this, "Application will now close. \n A restart may cure the error!\n\n" + e.getMessage(), "Fatal Error", JOptionPane.WARNING_MESSAGE, null); System.exit(3); } catch (BadLocationException e){ JOptionPane.showMessageDialog(ChatGUI.this, "Application will now close. \n A restart may cure the error!\n\n" + e.getMessage(), "Fatal Error", JOptionPane.WARNING_MESSAGE, null); System.exit(4); } statusBar.setText("Chat History Saved"); } } } } /** * Process return key for sending the message */ private class MyKeyAdapter extends KeyAdapter { @Override @SuppressWarnings("static-access") public void keyPressed(KeyEvent ke) { DateTime dateTime = new DateTime(); String nowdateTime = dateTime.getDateTime(); int kc = ke.getKeyCode(); if (kc == ke.VK_ENTER) { try { // Process only if there is data if (textPaneHome.getText().length() > 0){ // Add message origin formatting StyledDocument doc = (StyledDocument)textPaneHistory.getDocument(); Style style = doc.addStyle("HomeStyle", null); StyleConstants.setBold(style, true); String home = "Home [" + nowdateTime + "]: "; doc.insertString(doc.getLength(), home, style); StyleConstants.setBold(style, false); doc.insertString(doc.getLength(), textPaneHome.getText() + "\n", style); // update caret location textPaneHistory.setCaretPosition(doc.getLength()); textPaneHome.setText(null); statusBar.setText("Message Sent"); } } catch (BadLocationException e) { JOptionPane.showMessageDialog(ChatGUI.this, "Application will now close. \n A restart may cure the error!\n\n" + e.getMessage(), "Fatal Error", JOptionPane.WARNING_MESSAGE, null); System.exit(1); } ke.consume(); } } } }

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  • How to make safe cast using generics in C#?

    - by TN
    I want to implement a generic method on a generic class which would allow to cast safely, see example: public class Foo<T> : IEnumerable<T> { ... public IEnumerable<R> SafeCast<R>() where T : R { return this.Select(item => (R)item); } } However, the compiler tells me that Foo<T>.SafeCast<R>() does not define parameter 'T'. I understand this message that I cannot specify a constraint on T in the method since it is not defined in the method. But how can I specify an inverse constraint?

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  • Poll Results: Foreign Key Constraints

    - by Darren Gosbell
    A few weeks ago I did the following post asking people – if they used foreign key constraints in their star schemas. The poll is still open if you are interested in adding to it, but here is what the chart looks like as of today. (at the bottom of the poll itself there is a link to the live results, unfortunately I cannot link the live results in here as the blogging platform blocks the required javascript)   Interestingly the results are fairly even. Of the 78 respondents, fractionally over half at least aim to start with referential integrity in their star schemas. I did not want to influence the results by sharing my opinion, but my personal preference is to always aim to have foreign key constraints. But at the same time, I am pragmatic about it, I do have projects where for various reasons some constraints are not defined. And I also have other designs that I have inherited, where it would just be too much work to go back and add foreign key constraints. If you are going to implement foreign keys in your star schema, they really need to be there at the start. In fact this poll was was the result of a feature request for BIDSHelper asking for a feature to check for null/missing foreign keys and I am entirely convinced that BIDS is the wrong place for this sort of functionality. BIDS is a design tool, your data needs to be constantly checked for consistency. It's not that I think that it's impossible to get a design working without foreign key constraints, but I like the idea of failing as soon as possible if there is an error and enforcing foreign key constraints lets me "fail early" if there are constancy issues with my data. By far the biggest concern with foreign keys is performance and I suppose I'm curious as to how often people actually measure and quantify this. I worked on a project a number of years ago that had very large data volumes and we did find that foreign key constraints did have a measurable impact, but what we did was to disable the constraints before loading the data, then enabled and checked them afterwards. This saved as time (although not as much as not having constraints at all), but still let us know early in the process if there were any consistency issues. For the people that do not have consistent data, if you have ETL processes that you control that are building your star schema which you also control, then to be blunt you only have yourself to blame. It is the job of the ETL process to make the data consistent. There are techniques for handling situations like missing data as well as  early and late arriving data. Ralph Kimball's book – The Data Warehouse Toolkit goes through some design patterns for handling data consistency. Having foreign key relationships can also help the relational engine to optimize queries as noted in this recent blog post by Boyan Penev

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  • Type dependencies vs directory structure

    - by paul
    Something I've been wondering about recently is how to organize types in directories/namespaces w.r.t. their dependencies. One method I've seen, which I believe is the recommendation for both Haskell and .NET (though I can't find the references for this at the moment), is: Type Type/ATypeThatUsesType Type/AnotherTypeThatUsesType My natural inclination, however, is to do the opposite: Type Type/ATypeUponWhichTypeDepends Type/AnotherTypeUponWhichTypeDepends Questions: Is my inclination bass-ackwards? Are there any major benefits/pitfalls of one over the other? Is it just something that depends on the application, e.g. whether you're building a library vs doing normal coding?

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  • AWT Textfield behaves weird with MicroSoft JVM

    - by AKh
    Hi, I am facing a weird problem when using MicroSoft JVM to run my Applet. I have an AWT panel with 4 textfields which is added to a dialog box. Everything goes fine until I enter a decimal value into the textfield and close the dialog box. When i reopen the dialog box the textfield inside the panel with all the decimal digits (entered in the previous step) behaves weird. The decimal values along with the WHITE area inside the textfield moves to the left and hides the digits. When I click inside the textfield it becomes normal. The Panel earlier had gridlayout and I even tried changing it to gridbaylayout and still the problem persist. NOTE: All Development are pertained to JRE1.1 to compatibility with MS JVM If any can help me with this it would be a great help. Thanks in advance. . . . . public MyPanel(Dialog myDialog) { Panel panel = new Panel(); this.dialog = myDialog; //Previous code with grid layout /* panel.setLayout(new GridLayout2(4,2,2,2)); panel.add(new Label("Symbol:")); panel.add(symbolField = new TextField("",20)); panel.add(new Label("Quantity:")); panel.add( qtyField = new TextField()); panel.add(new Label("Price per Share:")); panel.add( costField = new TextField()); panel.add(new Label("Date Acquired:")); panel.add( purchaseDate = new TextField() );*/ GridBagLayout gridbag = new GridBagLayout(); System.out.println("######## Created New GridBagLayout"); GridBagConstraints constraints = new GridBagConstraints(); panel.setLayout( gridbag ); constraints = buildConstraints( constraints, 0, 0, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( new Label("Symbol:"), constraints); constraints = buildConstraints( constraints, 1, 0, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( symbolField = new TextField("",20), constraints); constraints = buildConstraints( constraints, 0, 1, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( new Label("Quantity:"), constraints); constraints = buildConstraints( constraints, 1, 1, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( qtyField = new TextField(), constraints); constraints = buildConstraints( constraints, 0, 2, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( new Label("Price per Share:"), constraints); constraints = buildConstraints( constraints, 1, 2, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( costField = new TextField(), constraints); constraints = buildConstraints( constraints, 0, 3, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( new Label("Date Acquired:"), constraints); constraints = buildConstraints( constraints, 1, 3, 1, 1, 1.5, 1 ); constraints.anchor = GridBagConstraints.WEST; constraints.fill = GridBagConstraints.HORIZONTAL; panel.add( purchaseDate = new TextField(), constraints); .............. ......... }

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  • Accessing type-parameter of a type-parameter

    - by itemState
    i would like to access, in a trait, the type-parameter of a type-parameter of that trait. without adding this "second-order" type-parameter as another "first-order" parameter to the trait. the following illustrates this problem: sealed trait A; sealed trait A1 extends A; sealed trait A2 extends A trait B[ ASpecific <: A ] { type ASpec = ASpecific } trait D[ ASpecific <: A ] extends B[ ASpecific ] trait C[ +BSpecific <: B[ _ <: A ]] { def unaryOp : C[ D[ BSpecific#ASpec ]] } def test( c: C[ B[ A1 ]]) : C[ D[ A1 ]] = c.unaryOp the test fails to compile because apparently, the c.unaryOp has a result of type C[D[A]] and not C[D[A1]], indicating that ASpec is merely a shortcut for _ <: A and does not refer to the specific type parameter. the two-type-parameter solution is simple: sealed trait A; sealed trait A1 extends A; sealed trait A2 extends A trait B[ ASpecific <: A ] trait D[ ASpecific <: A ] extends B[ ASpecific ] trait C[ ASpecific <: A, +BSpecific <: B[ ASpecific ]] { def unaryOp : C[ ASpecific, D[ ASpecific ]] } def test( c: C[ A1, B[ A1 ]]) : C[ A1, D[ A1 ]] = c.unaryOp but i don't understand why i need to clutter my source with this second, obviously redundant, parameter. is there no way to retrieve it from trait B?

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  • Change type of control by type

    - by Ruben
    Hi, I'm having following problem. I should convert a control to a certain type, this can be multiple types (for example a custom button or a custom label, ....) Here's an example of what i would like to do: private void ConvertToTypeAndUseCustomProperty(Control c) { Type type = c.getType(); ((type) c).CustomPropertieOfControl = 234567; } Thanks in advance.

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  • IIS website is sending multiple content-type headers for zip files

    - by frankadelic
    We have a problem with an IIS5 server. When certain users/browsers click to download .zip files, binary gibberish text sometimes renders in the browser window. The desired behavior is for the file to either download or open with the associated zip application. Initially, we suspected that the wrong content-type header was set on the file. The IIS tech confirmed that .zip files were being served by IIS with the mime-type "application/x-zip-compressed". However, an inspection of the HTTP packets using Wireshark reveals that requests for zip files return two Content-Type headers. Content-Type: text/html; charset=UTF-8 Content-Type: application/x-zip-compressed Any idea why IIS is sending two content-type headers? This doesn't happen for regular HTML or images files. It does happen with ZIP and PDF. Is there a particular place we can ask the IIS tech to look? Or is there a configuration file we can examine?

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  • Converting raw data type to enumerated type

    - by Jim Lahman
    There are times when an enumerated type is preferred over using the raw data type.  An example of using a scheme is when we need to check the health of x-ray gauges in use on a production line.  Rather than using a scheme like 0, 1 and 2, we can use an enumerated type: 1: /// <summary> 2: /// POR Healthy status indicator 3: /// </summary> 4: /// <remarks>The healthy status is for each POR x-ray gauge; each has its own status.</remarks> 5: [Flags] 6: public enum POR_HEALTH : short 7: { 8: /// <summary> 9: /// POR1 healthy status indicator 10: /// </summary> 11: POR1 = 0, 12: /// <summary> 13: /// POR2 healthy status indicator 14: /// </summary> 15: POR2 = 1, 16: /// <summary> 17: /// Both POR1 and POR2 healthy status indicator 18: /// </summary> 19: BOTH = 2 20: } By using the [Flags] attribute, we are treating the enumerated type as a bit mask.  We can then use bitwise operations such as AND, OR, NOT etc. . Now, when we want to check the health of a specific gauge, we would rather use the name of the gauge than the numeric identity; it makes for better reading and programming practice. To translate the numeric identity to the enumerated value, we use the Parse method of Enum class: POR_HEALTH GaugeHealth = (POR_HEALTH) Enum.Parse(typeof(POR_HEALTH), XrayMsg.Gauge_ID.ToString()); The Parse method creates an instance of the enumerated type.  Now, we can use the name of the gauge rather than the numeric identity: 1: if (GaugeHealth == POR_HEALTH.POR1 || GaugeHealth == POR_HEALTH.BOTH) 2: { 3: XrayHealthyTag.Name = Properties.Settings.Default.POR1XRayHealthyTag; 4: } 5: else if (GaugeHealth == POR_HEALTH.POR2) 6: { 7: XrayHealthyTag.Name = Properties.Settings.Default.POR2XRayHealthyTag; 8: }

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  • Why to say, my function is of IFly type rather than saying it's Airplane type

    - by Vishwas Gagrani
    Say, I have two classes: Airplane and Bird, both of them fly. Both implement the interface IFly. IFly declares a function StartFlying(). Thus both Airplane and Bird have to define the function, and use it as per their requirement. Now when I make a manual for class reference, what should I write for the function StartFlying? 1) StartFlying is a function of type IFly . 2) StartFlying is a function of type Airplane 3) StartFlying is a function of type Bird. My opinion is 2 and 3 are more informative. But what i see is that class references use the 1st one. They say what interface the function is declared in. Problem is, I really don't get any usable information from knowing StartFlying is IFly type. However, knowing that StartFlying is a function inside Airplane and Bird, is more informative, as I can decide which instance (Airplane or Bird ) to use. Any lights on this: how saying StartFlying is a function of type IFly, can help a programmer understanding how to use the function?

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  • determine complex type from a primitive type using reflection

    - by Nilotpal Das
    I am writing a tool where I need to reflect upon methods and if the parameters of the methods are complex type, then I need to certain type of actions such as instantiating them etc. Now I saw the IsPrimitive property in the Type variable. However, it shows string and decimal as complex types, which technically isn't incorrect. However what I really want is to be able to distinguish developer created class types from system defined data types. Is there any way that I can do this?

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  • Hot to get generic type from object type

    - by Murat
    My Classes are; class BaseClass { } class DerivedClass1 : BaseClass { } class GenericClass<T> { } class DerivedClass2 : BaseClass { GenericClass<DerivedClass1> subItem; } I want to access all fields of DerivedClass2 class. I use System.Reflection and FieldInfo.GetValue() method; Bu I cant get subItem field. FieldInfo.GetValue() method return type is "object". And I cant cast to GenericClass<DerivedClass1> or I cant get DerivedClass1 type. I try this with BaseClass BaseClass instance = FieldInfo.Getvalue(this) as GenericClass<BaseClass>; but instance is null. How to get instance with type or how to get only type?

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