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What is a Context Free Grammar?
...le of a formal language is the set of all binary strings of length three, {000, 001, 010, 011, 100, 101, 110, 111}.
Grammars work by defining transformations you can make to construct a string in the language described by a grammar. Grammars will say how to transform a start symbol (usually S) into...
How do I modify a MySQL column to allow NULL?
MySQL 5.0.45
6 Answers
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Alter Table Add Column Syntax
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edited Apr 27 '09 at 17:02
Eoin Campbell
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Break when exception is thrown
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You are able to define the precise list of Exception you want to have a breakpoint on, even if ...
Does a dot have to be escaped in a character class (square brackets) of a regular expression?
... lilactiger89lilactiger89
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Get week of year in JavaScript like in PHP
...uk/js-date6.htm#YWD. Please test thoroughly, no guarantee provided.
Edit 2017
There was an issue with dates during the period that daylight saving was observed and years where 1 Jan was Friday. Fixed by using all UTC methods. The following returns identical results to Moment.js.
/* For a give...
How to check for a valid Base64 encoded string
...e64 string, as it will only be composed of characters 'A'..'Z', 'a'..'z', '0'..'9', '+', '/' and it is often padded at the end with up to three '=', to make the length a multiple of 4. But instead of comparing these, you'd be better off ignoring the exception, if it occurs.
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Crontab - Run in directory
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answered Jan 17 '12 at 18:40
Gilles 'SO- stop being evil'Gilles 'SO- stop being evil'
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How to add lines to end of file on Linux
...t"' >> /etc/sysconfig/configfile
echo 'VNCSERVERARGS[1]="-geometry 1600x1200"' >> /etc/sysconfig/configfile
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File content into unix variable with newlines
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answered May 7 '10 at 14:44
paxdiablopaxdiablo
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