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How to define “type disjunction” (union types)?

...str") case _: Int => println("int") } } And that's it. You can call foo(5) or foo("abc"), and it will work, but try foo(true) and it will fail. This could be side-stepped by the client code by creating a StringOrInt[Boolean], unless, as noted by Randall below, you make StringOrInt a seale...
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Copy a table from one database to another in Postgres

...ant, works great, just don't forget to set Disable triggers when exporting all database – norbertas.gaulia Sep 4 '15 at 15:38  |  show 2 more ...
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Is a Python list guaranteed to have its elements stay in the order they are inserted in?

...answer so I don't want to add another. He could also use list.append to really put his mind at ease. docs.python.org/2/tutorial/datastructures.html – NG. Dec 4 '12 at 0:15 1 ...
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What does @: (at symbol colon) mean in a Makefile?

...nd nothing gets done. For example (from Linux's scripts/Makefile.clean): __clean: $(subdir-ymn) ifneq ($(strip $(__clean-files)),) +$(call cmd,clean) endif ifneq ($(strip $(__clean-dirs)),) +$(call cmd,cleandir) endif ifneq ($(strip $(clean-rule)),) +$(clean-rule) endif @: ...
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How is this fibonacci-function memoized?

...nacci definition, fib n = fib (n-1) + fib (n-2), the function itself gets called, twice from the top, causing the exponential explosion. But with that trick, we set out a list for the interim results, and go "through the list": fib n = (xs!!(n-1)) + (xs!!(n-2)) where xs = 0:1:map fib [2..] The tr...
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convert_tz returns null

...ving these files to a different location such as /usr/share/zoneinfo/.bak/ allows for the command mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql to fully populate all of the expected timezone information. This may or may not be a bug in my installed version of MySQL: $ mysql -...
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How do I run IDEA IntelliJ on Mac OS X with JDK 7?

...will not work with JDK 1.7 on Mac. At the moment you must have JDK 1.6 installed so that you can run IDEA 11 and older versions. share | improve this answer | follow ...
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Combining two expressions (Expression)

...m); } Starting from .NET 4.0, there is the ExpressionVisitor class which allows you to build expressions that are EF safe. public static Expression<Func<T, bool>> AndAlso<T>( this Expression<Func<T, bool>> expr1, Expression<Func<T, bool>&...
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Validating email addresses using jQuery and regex

...EmailAddress(emailAddress) { var pattern = /^([a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+(\.[a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|"((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\u...
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How to make an app's background image repeat

I have set a background image in my app, but the background image is small and I want it to be repeated and fill in the whole screen. What should I do? ...