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Why is lazy evaluation useful?
...epending on the sequence of conditional expressions, only a subset may actually be used. In a language like C, all three values would be computed anyway; but in Haskell, only the necessary values are computed.
It also allows for cool stuff like infinite lists. I can't have an infinite list in a lan...
Linux vi arrow keys broken in insert mode
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@pts - only on broken systems. Starting vim as vi on all of my boxes works just fine; however, there are some CentOS boxes I have used that demonstrate the behavior you are talking about.
– Chas. Owens
May 1 '09 at 22:22
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Cache Invalidation — Is there a General Solution?
...ched value of b. If you chose 2 you must still check b every time but can fall back on the cache for a if b checks out.
If you layer caches you must consider whether you have violated the 'rules' of the system as a result of the combined behaviour.
If you know that a always has validity if b does...
In eclipse, unable to reference an android library project in another android project
... referencing project in the same physical folder as the library project it all went fine.
I guess that this must be something to do with android using ant underneath the covers.
Edit: The project name needs match the folder name on the file system. What you are seeing in the Project Properties->...
How to run Node.js as a background process and never die?
...ill %2 with the number being the index of the process.
Powerful solution (allows you to reconnect to the process if it is interactive):
screen
You can then detach by pressing Ctrl+a+d and then attach back by running screen -r
Also consider the newer alternative to screen, tmux.
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How do I “commit” changes in a git submodule? [duplicate]
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@rogerdpack - you're correct. Submodules usually end up on "no branch". You'll often need to check out some branch before adding/committing to your submodule.
– timdev
Dec 23 '11 at 16:57
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Best practices for SQL varchar column length [closed]
...ax length that is not a power of 2.
I think early SQL Server versions actually treated a VARCHAR with length 255 differently than one with a higher maximum length. I don't know if this is still the case.
For almost all DBMS, the actual storage that is required is only determined by the number of ...
How do I remedy “The breakpoint will not currently be hit. No symbols have been loaded for this docu
...ugging, as soon as you've arrived at a breakpoint or used Debug > Break All, use Debug > Windows > Modules. You'll see a list of all the assemblies that are loaded into the process. Locate the one you want to get debug info for. Right-click it and select Symbol Load Information. You'll ...
MySQL order by before group by
...rect author and post is returned every time.
As a side note, while MySQL allows you to use an ORDER BY in a subquery and allows you to apply a GROUP BY to not every column in the SELECT list this behavior is not allowed in other databases including SQL Server.
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Practical uses of git reset --soft?
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git reset is all about moving HEAD, and generally the branch ref.
Question: what about the working tree and index?
When employed with --soft, moves HEAD, most often updating the branch ref, and only the HEAD.
This differ from commit --ame...