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How was the first compiler written?
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Assembly instructions are (generally) a direct mapping to opcodes, which are (multi-)byte values of machine code that can be directly interpreted by the processor. It is quite possible to write a program in opcodes directly by looking them up from a table (...
Where is the 'tests output pane'?
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The message really should be this
Unexpected error detected. Check the Output Window for details which can be found in the Show output from: section. Then select the Tests drop down to read the actual error.
For it is in the output windo...
How can I view the source code for a function?
...a.frame"
x="Raster", y="Extent"
x="Raster", y="matrix"
x="Raster", y="SpatialLines"
x="Raster", y="SpatialPoints"
x="Raster", y="SpatialPolygons"
x="Raster", y="vector"
To see the source code for one of these methods the entire signature must be supplied, e.g.
getMethod("extract" , signature = c(...
rotating axis labels in R
In R, how do I make a (bar)plot's y axis labels parallel to the X axis instead of parallel to the Y axis?
5 Answers
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In Ruby, is there an Array method that combines 'select' and 'map'?
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I usually use map and compact together along with my selection criteria as a postfix if. compact gets rid of the nils.
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}
=> [3, 3, 3, nil, nil, nil]
jruby-1.5.0 > [1...
When tracing out variables in the console, How to create a new line?
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In ES6/ES2015 you can use string literal syntax called template literals. Template strings use backtick character instead of single quote ' or double quote marks ". They also preserve new line and tab
const roleName = 'test1';
const role_ID = 'test2';
const modal_ID ...
Reading output of a command into an array in Bash
...tput of a command in an array, with one line per element, there are essentially 3 ways:
With Bash≥4 use mapfile—it's the most efficient:
mapfile -t my_array < <( my_command )
Otherwise, a loop reading the output (slower, but safe):
my_array=()
while IFS= read -r line; do
my_array+...
Stream vs Views vs Iterators
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First, they are all non-strict. That has a particular mathematical meaning related to functions, but, basically, means they are computed on-demand instead of in advance.
Stream is a lazy list indeed. In fact, in Scala, a Stream is a List wh...
Get first key in a (possibly) associative array?
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2019 Update
Starting from PHP 7.3, there is a new built in function called array_key_first() which will retrieve the first key from the given array without resetting the internal pointer. Check out the documentation for more info.
You can use reset and key:
reset($array);
$first_key = key(...
Git: Correct way to change Active Branch in a bare repository?
I have a bare repository that's used as the central store for my project. All the developers do git clone <repo> to share with it. When they do the clone, they get a checkout of the master branch (unless they do git clone -n ) because repo.git/HEAD contains ref: refs/heads/master , mak...