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What is the difference between the Data Mapper, Table Data Gateway (Gateway), Data Access Object (DA
... skills, and I'm curious what are the differences between these patterns? All of them seem like they are the same thing - encapsulate the database logic for a specific entity so the calling code has no knowledge of the underlying persistence layer. From my brief research all of them typically impl...
What is an existential type?
... one type and one value. The universal proof is an entire family of values indexed by type (or a mapping from types to values).
So the difference between the two types you specified is as follows:
T = ∃X { X a; int f(X); }
This means: A value of type T contains a type called X, a value a:X, an...
Merging dictionaries in C#
...roupBy would be better suited than ToLookup ? I think ILookup just adds an indexer, size property and contains method on top of IGrouping - so it got to be a tiny little bit faster ?
– toong
May 30 '13 at 15:25
...
JavaScript get clipboard data on paste event (Cross browser)
...nce writing this answer: now that Firefox has added support in version 22, all major browsers now support accessing the clipboard data in a paste event. See Nico Burns's answer for an example.
In the past this was not generally possible in a cross-browser way. The ideal would be to be able to get t...
Why doesn't the height of a container element increase if it contains floated elements?
...ck level above the normal floated elements. (Please don't relate this to z-index as that is completely different.)
Taking a case as an example to explain how CSS floats work, assuming we need a simple 2 column layout with a header, footer, and 2 columns, so here is what the blueprint looks like....
Can someone explain __all__ in Python?
I have been using Python more and more, and I keep seeing the variable __all__ set in different __init__.py files. Can someone explain what this does?
...
fastest MD5 Implementation in JavaScript
...
I've heard Joseph's Myers implementation is quite fast. Additionally, he has a lengthy article on Javascript optimization describing what he learned while writing his implementation. It's a good read for anyone interested in performant javascript.
http://www.webreference.com/programming/...
MongoDB: Find a document by non-existence of a field?
...
+1. However, keep in mind that such queries can't use indexing and might be very slow on large collections.
– mnemosyn
Dec 19 '11 at 21:12
10
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.append(), prepend(), .after() and .before()
...
See:
.append() puts data inside an element at last index and
.prepend() puts the prepending elem at first index
suppose:
<div class='a'> //<---you want div c to append in this
<div class='b'>b</div>
</div>
when .append() executes it will look li...
“No X11 DISPLAY variable” - what does it mean?
...ror.
Download this app xming:
http://sourceforge.net/project/downloading.php?
Install, then use settings on this link:
http://www.geo.mtu.edu/geoschem/docs/putty_install.html or follow this steps:
Installing/Configuring PuTTy and Xming
Once PuTTy and Xming have been downloaded to the PC, insta...