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How can you determine a point is between two other points on a line segment?

...def distance(a,b): return sqrt((a.x - b.x)**2 + (a.y - b.y)**2) def is_between(a,c,b): return distance(a,c) + distance(c,b) == distance(a,b) share | improve this answer | ...
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Property getters and setters

...g to backup the computed property. Try this: class Point { private var _x: Int = 0 // _x -> backingX var x: Int { set { _x = 2 * newValue } get { return _x / 2 } } } Specifically, in the Swift REPL: 15> var pt = Point() pt: Point = { _x = 0 } 16> pt.x = 10...
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Unique fields that allow nulls in Django

...pty string by providing your own customized model form for Foo with a clean_bar method that turns the empty string into None: class FooForm(forms.ModelForm): class Meta: model = Foo def clean_bar(self): return self.cleaned_data['bar'] or None class FooAdmin(admin.ModelAdmin...
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How to create a GUID/UUID using iOS

...tring = CFUUIDCreateString(NULL, theUUID); CFRelease(theUUID); return (__bridge NSString *)string; } EDIT: Jan, 29 2014: If you're targeting iOS 6 or later, you can now use the much simpler method: NSString *UUID = [[NSUUID UUID] UUIDString]; ...
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How to initialize private static members in C++?

... Have you found the explanation? @Krishna_Oza – nn0p Sep 14 '16 at 9:16 @nn0p not ye...
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How to pass command line arguments to a shell alias? [duplicate]

...osted for other shells, in Bash the following works: alias blah='function _blah(){ echo "First: $1"; echo "Second: $2"; };_blah' Running the following: blah one two Gives the output below: First: one Second: two shar...
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How to model type-safe enum types?

... val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value } import WeekDay._ def isWorkingDay(d: WeekDay) = ! (d == Sat || d == Sun) WeekDay.values filter isWorkingDay foreach println } share | ...
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How do I find which rpm package supplies a file I'm looking for?

As an example, I am looking for a mod_files.sh file which presumably would come with the php-devel package. I guessed that yum would install the mod_files.sh file with the php-devel x86_64 5.1.6-23.2.el5_3 package, but the file appears to not to be installed on my filesystem. ...
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What is the _snowman param in Ruby on Rails 3 forms for?

...n Ruby on Rails 3 (currently using Beta 4), I see that when using the form_tag or form_for helpers there is a hidden field named _snowman with the value of ☃ ( Unicode \x9731) showing up. ...
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Vim: insert the same characters across multiple lines

...e (Ctrlv). Press j three times (or 3j). Press I (capital i). Type in vendor_. Note: It will only update the screen in the first line - until Esc is pressed (6.), at which point all lines will be updated. Press Esc. An uppercase I must be used rather than a lowercase i, because the lowercase i is...