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How to flatten tree via LINQ?
...lt;T>> f
) => e.SelectMany(c => f(c).Flatten(f)).Concat(e);
Call this function like this:
IEnumerable<MyNode> tree = ....
var res = tree.Flatten(node => node.Elements);
If you would prefer flattening in pre-order rather than in post-order, switch around the sides of the Con...
How to “undelete” a deleted folder in Subversion / TortoiseSVN?
We have accidentally deleted the 'tags' folder from our Subversion repository where we only intended to delete one specific tag. What is the easiest way to get the 'tags' folder back?
...
shortcut for creating a Map from a List in groovy?
...
Check out "inject". Real functional programming wonks call it "fold".
columns.inject([:]) { memo, entry ->
memo[entry.name] = entry.val
return memo
}
And, while you're at it, you probably want to define methods as Categories instead of right on the metaClass. That ...
CSS Background Opacity [duplicate]
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It's not really correct to say that "Children inherit opacity". They don't. It's just that if a child is contained in a parent with opacity, the child will have opacity: 1, but the parent applies it's opacity to itself including all it'...
When to use Common Table Expression (CTE)
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I use them to break up complex queries, especially complex joins and sub-queries. I find I'm using them more and more as 'pseudo-views' to help me get my head around the intent of the query.
My only complaint about them is they cannot be re-used. For example, I may have...
Make virtualenv inherit specific packages from your global site-packages
...ch will contain just some libraries (which i chose) of the base python installation.
4 Answers
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How do I drag and drop files into an application?
...orm1 : Form {
public Form1() {
InitializeComponent();
this.AllowDrop = true;
this.DragEnter += new DragEventHandler(Form1_DragEnter);
this.DragDrop += new DragEventHandler(Form1_DragDrop);
}
void Form1_DragEnter(object sender, DragEventArgs e) {
if (e.Data....
.htaccess - how to force “www.” in a generic way?
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This solution works only if you want all sub-domains forwarded to www.yourdomain.com. If you only want to force www, you should update the second line to be: RewriteCond %{HTTP_HOST} ^yourdomain.com [NC]
– Jared Pomranky
Ma...
Application Loader: “Cannot proceed with delivery: an existing transporter instance is currently upl
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Basically, you need to clear out the transport tokens. This can happen if you were to close out of Xcode while in the middle of submitting an app to iTunes Connect.
The token files now appear in the
Library/Caches/com.apple.amp.i...
Can a foreign key be NULL and/or duplicate?
...at field must exist first in a different table (the parent table). That is all an FK is by definition. Null by definition is not a value. Null means that we do not yet know what the value is.
Let me give you a real life example. Suppose you have a database that stores sales proposals. Suppose furth...