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What are the differences between Clojure, Scheme/Racket and Common Lisp?
...ew, if possible, covering topics such as syntax, characteristics, features and resources.
4 Answers
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How can I get the SQL of a PreparedStatement?
...ou have a statement, containing placeholders
it is sent to the DB server
and prepared there
which means the SQL statement is "analysed", parsed, some data-structure representing it is prepared in memory
And, then, you have bound variables
which are sent to the server
and the prepared statement ...
Is it possible to target older iOS versions when using Xcode 4.2 and iOS 5 SDK?
I just recently downloaded the Xcode 4.2 with iOS 5 SDK package and I immediately noticed that I am unable to use my iPhone 3Gs with iOS 4.2.1 for debugging. I am only able to debug and test on my iphone 4 with iOS 5 installed.
...
How to use git with gnome-keyring integration
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I was hesitant to do this at first, but I did finally and it works perfectly. As the docs for gitcredentials say, you might also want to do git help -a | grep credential- and see if you have other helpers installed. Ones that come by default are credential-cache (remember passwo...
javascript function leading bang ! syntax
I've been seeing this syntax on a few libraries now and I'm wondering what the benefit is. (note i'm well aware of closures and what the code is doing, I'm only concerned about the syntactical differences)
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How can I change image tintColor in iOS and WatchKit
...mage.
You must add your image to an Asset Catalog in your WatchKit App, and set the image set to be rendered as a Template Image in the Attributes Inspector. Unlike for an iPhone app, you cannot set the template rendering in code in the WatchKit Extension at present.
Set that image to be used in ...
Java String split removed empty values
...le more details:
split(regex) internally returns result of split(regex, 0) and in documentation of this method you can find (emphasis mine)
The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array.
If the limit n is greater than...
Remove duplicated rows using dplyr
...mple(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [3 x 3]
## Groups: x, y
##
## x y z
## 1 0 1 1
## 2 1 0 2
## 3 1 1 4
(In dplyr 0.2 you won't need...
Normal arguments vs. keyword arguments
...tion them after all of the arguments without names (positional arguments), and there must be default values for any parameters which were not mentioned at all.
The other concept is on the function definition side: you can define a function that takes parameters by name -- and you don't even have to...
Program only crashes as release build — how to debug?
...t a program nonetheless) is crashing, but only when built in release mode, and only when launched from the command line. Through caveman debugging (ie, nasty printf() messages all over the place), I have determined the test method where the code is crashing, though unfortunately the actual crash se...