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Why can't C++ be parsed with a LR(1) parser?
... other information (e.g., knowledge of the type of x) must collect both in order to decide later what to do. Thus a grammar must allow this. And that makes the grammar ambiguous.
Thus pure LR parsing can't handle this. Nor can many other widely available parser generators, such as Antlr, JavaCC, ...
How can i tell if an object has a key value observer attached
...SMutableArray like this:
- (void)addObservedObject:(id)object {
if (![_observedObjects containsObject:object]) {
[_observedObjects addObject:object];
}
}
If you want to unobserve the objects you can do something like:
for (id object in _observedObjects) {
if ([object isKindOf...
Is there a way to detect if a browser window is not currently active?
... too. Think about the same case as above, or a user watching a video.
In order to improve the imperfect behaviors described above, I use a combination of the 3 methods: W3C Visibility API, then focus/blur and user activity methods in order to reduce the false positive rate. This allows to manage t...
How to exclude a directory in find . command
... delete? For -delete to work, find needs to traverse the directory in DFS order, since -deletewill first delete the leaves, then the parents of the leaves, etc... But for specifying -prune to make sense, find needs to hit a directory and stop descending it, which clearly makes no sense with -depth ...
Restore the state of std::cout after manipulating it
...lude <iostream> or #include <ios> then when required:
std::ios_base::fmtflags f( cout.flags() );
//Your code here...
cout.flags( f );
You can put these at the beginning and end of your function, or check out this answer on how to use this with RAII.
...
_csv.Error: field larger than field limit (131072)
...
The csv file might contain very huge fields, therefore increase the field_size_limit:
import sys
import csv
csv.field_size_limit(sys.maxsize)
sys.maxsize works for Python 2.x and 3.x. sys.maxint would only work with Python 2.x (SO: what-is-sys-maxint-in-python-3)
Update
As Geoff pointed out,...
Avoid synchronized(this) in Java?
...angerous. You've now introduced a client-side (user's of this class) lock ordering requirement. If two threads are calling method1() and method2() in a different order, they are likely to deadlock, but the user of this class has no idea that this is the case.
– daveb
...
How to iterate over a JSONObject?
...e careful everyone, jObject.keys() returns the iterator with reverse index order.
– macio.Jun
Aug 31 '13 at 17:36
...
What is a thread exit code?
... returned from your process or thread as part of an exit code. The higher order bytes are used by the operating system to convey special information about the process. The exit code is very useful in batch/shell programs which conditionally execute other programs depending on the success or failur...
CSS hack大全 - 创意 - 清泛网 - 专注C/C++及内核技术
...0deff\9; /*IE6、7、8识别*/ +background-color:#a200ff;/*IE6、7识别*/ _background-color:#1e0bd1/*IE6识别*/}
@media screen and (-webkit-min-device-pixel-ratio:0){.bb{background-color:#f1ee18}}{} /* Safari(Chrome) 有效 */
@media all and (min-width: 0px){ .bb{background-color:#f1ee18;/*op...