大约有 15,660 项符合查询结果(耗时:0.0306秒) [XML]

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lexers vs parsers

...lar transducers may have others uses, such as formalization of some syntax error handling techniques.) BNF is just a specific syntax for presenting CF grammars. EBNF is a syntactic sugar for BNF, using the facilities of regular notation to give terser version of BNF grammars. It can always be tran...
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Why is a round-trip conversion via a string not safe for a double?

... - Mul64 will be called // at most twice during the conversion, so the error won't propagate // to any of the 53 significant bits of the result unsigned long long val = Mul32x32To64(a >> 32, b >> 32) + (Mul32x32To64(a >> 32, b) >> 32) + (Mul32x32To...
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What is the copy-and-swap idiom?

... swap(rhs); return *this; } The fundamental idea is that: the most error-prone part of assigning to an object is ensuring any resources the new state needs are acquired (e.g. memory, descriptors) that acquisition can be attempted before modifying the current state of the object (i.e. *this) ...
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C# Object Pooling Pattern implementation

...ses are private inner classes - that is why they don't need a whole lot of error-checking, the pool itself restricts access to them. Throw in an enumeration and a factory method and we're done with this part: // Outside the pool public enum AccessMode { FIFO, LIFO, Circular }; private IItemSt...
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Getting the closest string match

... Thanks. I edited out the error. The reason I started by describing the fixed-length array was because it's easy to understand. Suffix arrays and BWT are a bit harder to grasp, but actually we do sometimes want to use an index with different values of...
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What does .SD stand for in data.table in R

...he heterogeneity in this relationship as follows (noting that the standard errors from this approach are generally incorrect -- the specification ERA ~ W*teamID will be better -- this approach is easier to read and the coefficients are OK): # use the .N > 20 filter to exclude teams with few obse...
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Understanding __get__ and __set__ and Python descriptors

... @IshanBhatt: I think that's because of the error pointed out by musiphil above. Also, not this is not my answer – Eric Mar 7 '16 at 14:52 add a...
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Memcached vs. Redis? [closed]

... Redis can use. If this limit is reached Redis will start to reply with an error to write commands (but will continue to accept read-only commands), or you can configure it to evict keys when the max memory limit is reached in the case you are using Redis for caching. We have documentation if you pl...
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How to become an OpenCart guru? [closed]

... to use unit LOG $this->log->write($message) - Writes to the system error log REQUEST $this->request->clean($data) - Cleans the data coming in to prevent XSS $this->request->get['x'] - Same as $_GET['x'] $this->request->post['x'] - Same as $_POST['x'] RESPONSE $this->re...
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Logical operators for boolean indexing in Pandas

...as Series do not have a boolean value -- in other words, they raise ValueError: The truth value of an array is ambiguous. Use a.empty, a.any() or a.all(). when used as a boolean value. That's because its unclear when it should be True or False. Some users might assume they are True if they have ...