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Differences between Agda and Idris
... The latter is equivalent to a statement that the types are equal followed by one about the values. In a world where type equality is weird (HoTT) then heteq is a weirder statement.
– Mysterious Dan
Jan 9 '14 at 21:37
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List distinct values in a vector in R
...If it's not a factor, but it should be, you can convert it to factor first by using the factor() function, e.g.
levels( factor( data$product_code ) )
Another option, as mentioned above, is the unique() function:
unique( data$product_code )
The main difference between the two (when applied to a...
Creating a segue programmatically
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By definition a segue can't really exist independently of a storyboard. It's even there in the name of the class: UIStoryboardSegue. You don't create segues programmatically - it is the storyboard runtime that creates them ...
Insert text with single quotes in PostgreSQL
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String literals
Escaping single quotes ' by doubling them up -> '' is the standard way and works of course:
'user's log' -- incorrect syntax (unbalanced quote)
'user''s log'
In old versions or if you still run with standard_conforming_strings = off or, gene...
Unable to access JSON property with “-” dash
...ascript and its the native implementation to access an object property key by string, sure it works in everything on top
– john Smith
Jan 12 '16 at 22:15
1
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Python : List of dict, if exists increment a dict value, if not append a new dict
...ready-to-use class: containers.Counter You just create a Counter instance by calling the class, passing in any iterable; it builds a dictionary where the keys are values from the iterable, and the values are counts of how many times the key appeared in the iterable. The above example then becomes:...
The JPA hashCode() / equals() dilemma
...like to discuss them JPA-implementation-neutrally (I am using EclipseLink, by the way).
20 Answers
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Do HTML5 custom data attributes “work” in IE 6?
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I can get the value of data-geoff using
var geoff = document.getElementById("geoff");
alert(geoff.getAttribute("data-geoff"));
See MSDN. And although it is mentioned there that you need IE7 to get this to work, I tested this a while ago with IE6 and it functioned correctly (even in quirks mode...
How do I expire a PHP session after 30 minutes?
...You should implement a session timeout of your own. Both options mentioned by others (session.gc_maxlifetime and session.cookie_lifetime) are not reliable. I'll explain the reasons for that.
First:
session.gc_maxlifetime
session.gc_maxlifetime specifies the number of seconds after which data ...
Casting vs using the 'as' keyword in the CLR
...variables possible in every scope, you might still want to use is followed by a cast.
I don't think any of the answers so far (at the time of starting this answer!) have really explained where it's worth using which.
Don't do this:
// Bad code - checks type twice for no reason
if (randomObject...