packages

This question already has an answer here: Java packages com and org 4 answers In most source codes, the root package/folder is named "com". Why is that so? It it just convention or does it stand for something? The convention is that a programmer in a given organization will start package names with their organization's domain name, as a unique identifier -- in reverse order. This prevents namespace clashes between code from different organizations (within the organization you're on your own). So if I work for a company called Supercompany, and their domain is supercompany.com, all of my

I am using Octave on Window vista. I am using 4 package in my code. But every time I restart octave, I have to load manually from command line, 'pkg load ...' Is there a way to load them permanently so that whenever Octave is started it finds them in its path. When Octave starts, it runs ~/.octaverc . If you want Octave to automatically load a package, simply add a pkg load pkg-name command to it. If the files does not exist, create it. If you do this, remember that other people may not have Octave configured to load packages at startup. Therefore, if you write code for others, remember that

From Hadley's C best practices : Like with C++, whenever you use C code in your package, you should unload the DLL when the package is unloaded: .onUnload <- function (libpath) { library.dynam.unload("mypackage", libpath) } Writing R Extensions on the other hand doesn't even mention this. I can see how it would be polite to unload the dlls, but doing so seems to cause some weird problems for me with packages that are loaded/unloaded/reloaded (see example further down). Additionally, there are some mentions that suggest maybe unloading isn't required. From ?library.dynam : Note that whether or

Why do we use reverse domain name like com.something. or org.something. structure for java packages? I understand this brings in some sort of uniqueness, but why do we need this uniqueness? Globally unique package names avoid naming collisions between libraries from different sources. Rather than creating a new central database of global names, the domain name registry is used. From the JLS: The suggested convention for generating unique package names is merely a way to piggyback a package naming convention on top of an existing, widely known unique name registry instead of having to create a

del seems to have some memory which puzzles me. See the following: In [1]: import math In [2]: math.cos(0) Out[2]: 1.0 In [3]: del math.cos In [4]: math.cos(0) --------------------------------------------------------------------------- AttributeError Traceback (most recent call last) <ipython-input-4-9cdcc157d079> in <module>() ----> 1 math.cos(0) AttributeError: module 'math' has no attribute 'cos' Fine. Let's see what happens if we delete the whole math package: In [5]: del math In [6]: math.cos(0) --------------------------------------------------------------------------- NameError

Ok, I think whatever I'm doing wrong, it's probably blindingly obvious, but I can't figure it out. I've read and re-read the tutorial section on packages and the only thing I can figure is that this won't work because I'm executing it directly. Here's the directory setup: eulerproject/ __init__.py euler1.py euler2.py ... eulern.py tests/ __init__.py testeulern.py Here are the contents of testeuler12.py (the first test module I've written): import unittest from .. import euler12 class Euler12UnitTests(unittest.TestCase): def testtriangle(self): """ Ensure that the triangle number generator

I've installed the CL-PNG package using quicklisp. (ql:quicklisp 'png) Now I want to define my own package which depends on the CL-PNG package. Like so: (defpackage :FOO (:use :CL :PNG) (:export :BAR)) When compiling it I get this error: The name "PNG" does not designate any package. [Condition of type SB-KERNEL:SIMPLE-PACKAGE-ERROR] It seems that I have to call (require :PNG) on the REPL before compiling my package. What do I have to do to make the CL-PNG package available for the compiler without manually call require on the REPL? UPDATE: I'm using SBCL. You confuse two separate notions: a