I've started using Xcode 4, and I'm really annoyed by some of the "features" especially those semantic warnings which don't seem to be making much sense, for example:
http://coding-journal.com/wp-content/uploads/2011/08/Screen-Shot-2011-08-07-at-8.50.46-PM.png
On line 640, you can see a semantic issue saying that I am passing an incompatible pointer type to a parameter of NSString *, which is just plain wrong because the signature of NSTabViewItems' initWithIdentifier: is:
- (id)initWithIdentifier:(id)identifier
My guess is that Xcode thinks that I am calling initWithIdentifer: on some other object, because when I Cmd+Click the method, it gives me three options:
http://coding-journal.com/wp-content/uploads/2011/08/Screen-Shot-2011-08-07-at-8.50.24-PM.png
And the first one, from NSTableColumn, has the signature
- (id)initWithIdentifier:(NSString *)identifier;
So my question is, what do I do in this situation? I like my code warning-free, but this doesn't seem to be possible when using Xcode 4 :(
Related
Using Java 8u222, I've been trying a silly operation and it incurs in an error that I'm not being able to fully understand. The line code:
ZonedDateTime.parse("2011-07-03T02:20:46+06:00[Asia/Qostanay]");
The error:
java.time.format.DateTimeParseException: Text '2011-07-03T02:20:46+06:00[Asia/Qostanay]' could not be parsed, unparsed text found at index 25
at java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:1952)
at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1851)
at java.time.ZonedDateTime.parse(ZonedDateTime.java:597)
at java.time.ZonedDateTime.parse(ZonedDateTime.java:582)
Using the same date (although the timezone could be incorrect, the intention is just testing here), I changed the square bracket's value and it works, I mean:
ZonedDateTime.parse("2011-07-03T02:20:46+06:00[Europe/Busingen]);
It works as expected, as well as other values such:
ZonedDateTime.parse("2011-07-03T02:20:46+06:00[Asia/Ulan_Bator]")
ZonedDateTime.parse("2011-07-03T02:20:46+06:00[SystemV/CST6CDT]")
I found some similar questions such as the one below, but not precisely the same usage that I'm trying / facing.
Error java.time.format.DateTimeParseException: could not be parsed, unparsed text found at index 10
Does someone have an understanding of Java Date API to help me out to grasp what I'm doing wrong here?
Thanks.
Asia/Qostanay is a zone which doesn't exist in the JDK8's list of timezones. It was added later.
If you don't care about the location of the timezone then just splice the [...] part of the string off the end before parsing. Knowing that the time is +06:00 is going to sufficient for almost all purposes.
Alternatively, upgrade to a more recent version of Java.
I am new to sage and have got a code (link to code) which should run.
I am still getting an error message in the decoding part. The error trace looks like this:
in decode(y)
--> sigma[i+1+1] = sigma[i+1]*(z)\
-(delta[i+1]/delta[mu+1])*z^(i-mu)*sigma[mu+1]*(z);
in sage.structure.element.Element.__mul__
if BOTH_ARE_ELEMNT(cl):
--> return coercion_model.bin_op(left, right, mul)
in sage.structure.coerce.CoercionModel_cache_maps.bin_op
--> action = self.get_action(xp,yp,op,x,y)
...... some more traces (don't actually know if they are important)
TypeError: positive characteristics not allowed in symbolic computations
Does anybody know if there is something wrong in this code snipped? Due to previous errors, I changed the following to get to where I am at the moment:
.coeffs() changed to .coefficients(sparse=False) due to a warning message.
in the code line sigma[i+1+1] = sigma[i+1](z)\
-(delta[i+1]/delta[mu+1])*z^(i-mu)*sigma[mu+1](z); where the error occurs, i needed to insert * eg. sigma[i+1]*(z)
I would be grateful for any guess what could be wrong!
Your issue is that you are multiplying things not of characteristic zero (like elements related to Phi.<x> = GF(2^m)) with elements of symbolic computation like z which you have explicitly defined as a symbolic variable
Phi.<x> = GF(2^m)
PR = PolynomialRing(Phi,'z')
z = var('z')
Basically, the z you get from PR is not the same one as from var('z'). I recommend naming it something else. You should be able to access this with PR.gen() or maybe PR(z).
I'd be able to be more detailed, but I encourage you next time to paste a fully (non-)working example; trying to slog through a big worksheet is not the easiest thing to track all this down. Finally, good luck, hope Sage ends up being useful for you!
I'm trying to get started with OpenCL but came across weird behavior of the OpenCL compiler with respect to white-space and can't seem to find any documentation about that.
C-style single-line comments (// foo) immediately cause a meaningless build error: At end of source: error: expected a "}". Multi-line comments (/* bar */) seem to work fine.
Line breaks seem to get stripped without adding whitespace which can cause errors. This example will not compile because of that:
__kernel
void TestKernel() {}
line 1: error: identifier "__kernelvoid" is undefined
This may totally depend on my machine and/or configuration but can somebody confirm that these things should not be this way?
I am using OpenCL via Cloo from .net/C#. The driver is from AMD OpenCL 2.0 AMD-APP (1642.5)
I think I figured it out. I was doing this:
var program = new ComputeProgram(context, File.ReadAllLines(filename));
File.ReadAllLines() returns an array of strings without the line-break characters which is the root of the errors I was getting.
Using File.ReadAllTest() instead fixed all the problems:
var program = new ComputeProgram(context, File.ReadAllText(filename));
But in my opinion some of the blame goes to either Cloo or the OpenCL API for accepting a string array but just concatenating it together..
I am looking for a working distribution of SQLite for OpenVMS. I tried building SQLite 3.7.9 from the amalgamation file, using patches I found in a mailing list, but it does not quite work.
I am using HP C V7.1-015 on OpenVMS Alpha 7.3-2.
Since I cannot install python, which seems to include SQLite3, I have to build from sources.
I compile using the following commands:
$ CC /OPTIMIZE -
/DEFINE=(SQLITE_THREADSAFE=0, -
SQLITE_OMIT_LOAD_EXTENSION=1, -
SQLITE_OMIT_COMPILEOPTION_DIAGS=1, -
SQLITE_OMIT_MEMORYDB=1, -
SQLITE_OMIT_TEMPDB=1, -
SQLITE_OMIT_DEPRECATED=1, -
SQLITE_OMIT_SHARED_CACHE=1, -
_USE_STD_STAT=ENABLE) -
/FLOAT=IEEE_FLOAT -
sqlite3.c
$ CC /OPTIMIZE -
/DEFINE=(SQLITE_THREADSAFE=0, -
SQLITE_OMIT_LOAD_EXTENSION=1, -
SQLITE_OMIT_COMPILEOPTION_DIAGS=1, -
SQLITE_OMIT_MEMORYDB=1, -
SQLITE_OMIT_TEMPDB=1, -
SQLITE_OMIT_DEPRECATED=1, -
SQLITE_OMIT_SHARED_CACHE=1, -
_USE_STD_STAT=ENABLE) -
/FLOAT=IEEE_FLOAT -
shell.c
I copied the defines from the mailing list, and added /FLOAT=IEEE_FLOAT to get rid of most warnings regarding floating points (related to overflows due to exponent 308).
During compilation I got some informationals and warnings.
I get the following messages while linking:
$ LINK shell.obj,sqlite3.obj
...
%LINK-W-NUDFSYMS, 2 undefined symbols:
%LINK-I-UDFSYM, __STD_FSTAT
%LINK-I-UDFSYM, __STD_STAT
...
Since I am a little bit lost here, I rather have SQLite3 sources which compile on OpenVMS.
The specific problem you're getting from the linker arises from the fact that you've requested capability at compile time that your system doesn't have. I believe the _USE_STD_STAT option first became available in OpenVMS v8.2, yet you're on 7.3-2. Your compiler and your headers know what to do when _USE_STD_STAT is defined, but the functions to process the X/Open-compliant stat structure do not exist in the C run-time (CRTL in VMS parlance) on your system, and your linker is telling you, "ain't got those functions."
Ideally you would be able to upgrade your operating system. Current as of this writing is v8.4. v7.3-2 was released eight and a half years ago and v8.2 over seven years ago. I understand that there are technical, budgetary, and even political reason that upgrades aren't always possible. If it were me, and I were stuck on OpenVMS Alpha v7.3-2, I would try removing the _USE_STD_STAT=ENABLE from the compilation and see what blows up.
One of the side effects of enabling _USE_STD_STAT is that you also get _LARGEFILE along with it. If that's the only reason SQLite needs the option, you may be fine but limited to 4GB databases. I suspect there's more to it than that, i.e., SQLite very likely makes use of elements in the stat structure that do actually require the newer structure.
You can read up on the differences in the traditional and standards-compliant stat structures at http://h71000.www7.hp.com/doc/84final/5763/5763profile_062.html#index_x_1699.
I've recently improved my VMSish patch for SQLite and made it available for SQLite version 3.7.14.1: http://www.mail-archive.com/sqlite-users#sqlite.org/msg73570.html (or http://sqlite.1065341.n5.nabble.com/Building-SQLite-3-7-14-1-for-OpenVMS-td65277.html).
POSIX locking still doesn't work though, and I was unable to find out why.
Well, there was a message on the sqlite-users mailing list on getting SQLite 3.7.9 working on OpenVMS. I don't know how relevant that is to the version you've got (or if the patch was adopted by the SQLite developers; they're a bit picky for legal reasons IIRC) but it looks likely to be useful. Good luck.
The keyboard shortcut to jump to a particular line in Xcode is Cmd+L
Typing in line number easily works, but what is the "symbol" in "Type Line Number or Symbol"? I tried typing selector names, variable names, nothing seems to work. Anybody knows what the "symbol" here is referring to and how to use it?
I think this feature is not working and will not, ever. In the upcoming Xcode 4.5 you will see just "Type Line Number" without the "or Symbol" part.
This very same question has been filed to Apple, but without answers.
It appears that the only thing this does is jump by line number within the file. The same question can be found in the apple forums, unanswered as well.
Taking a loot at the same function in Xcode 3.2 should make it rather easy to understand:
The 'symbol' in 'type in line number or symbol' should thus probably mean 'symbol number n'. E.g. typing 24 will take you to the 24th symbol (character) in the code.
As I don't have the newest Xcode I can't test to confirm this myself but I doubt they changed the functionality.