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What does the “@” symbol mean in reference to lists in Haskell?
...hout the @, you'd have to choose between (1) or (2):(3).
This syntax actually works for any constructor; if you have data Tree a = Tree a [Tree a], then t@(Tree _ kids) gives you access to both the tree and its children.
s...
Changes in import statement python3
...a single function. In Python 2 you were permitted to be semi-lazy:
def sin_degrees(x):
from math import *
return sin(degrees(x))
Note that it already triggers a warning in Python 2:
a.py:1: SyntaxWarning: import * only allowed at module level
def sin_degrees(x):
In modern Python 2 co...
Get the _id of inserted document in Mongo database in NodeJS
...ection.insert that will return the doc or docs inserted, which should have _ids.
Try:
collection.insert(objectToInsert, function(err,docsInserted){
console.log(docsInserted);
});
and check the console to see what I mean.
...
What is two way binding?
...ners). Other frameworks like Knockout do wire up two-way binding automagically.
In Backbone, you can easily achieve #1 by binding a view's "render" method to its model's "change" event. To achieve #2, you need to also add a change listener to the input element, and call model.set in the handle...
How do I add custom field to Python log format string?
...LoggerAdapter so you don't have to pass the extra info with every logging call:
import logging
extra = {'app_name':'Super App'}
logger = logging.getLogger(__name__)
syslog = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s %(app_name)s : %(message)s')
syslog.setFormatter(formatte...
is_file or file_exists in PHP
I need to check if a file is on HDD at a specified location ($path.$file_name).
5 Answers
...
Suppressing “is never used” and “is never assigned to” warnings in C#
I have a HTTPSystemDefinitions.cs file in C# project which basically describes the older windows ISAPI for consumption by managed code.
...
Configuring so that pip install can work from github
...oo would be:
foo # the installable package
├── foo
│ ├── __init__.py
│ └── bar.py
└── setup.py
And install from github like:
$ pip install git+ssh://git@github.com/myuser/foo.git
or
$ pip install git+https://github.com/myuser/foo.git@v123
or
$ pip install git+htt...
Java: int array initializes with nonzero elements
...here it is not. Such a behavior occurs first in JDK 7u4 and also occurs in all later updates (I use 64-bit implementation). The following code throws exception:
...
When would I use Task.Yield()?
... a lot but have never been using Task.Yield() and to be honest even with all the explanations I do not understand why I would need this method.
...