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What are the differences between Clojure, Scheme/Racket and Common Lisp?
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The people above missed a few things
Common Lisp has vectors and hash tables as well. The difference is that Common Lisp uses #() for vectors and no syntax for hash tables. Scheme has vectors, I believe
Common Lisp has reader macros, which allow you to use new brackets (as does Racket, a descen...
PostgreSQL return result set as JSON array?
...scribes how to generate a JSON object, with each key being a column in the table and each value being an array of the values of the column. It's the result that looks like this:
{"a":[1,2,3], "b":["value1","value2","value3"]}
9.5 and up
We can leverage the json_build_object function:
SELECT
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Seeding the random number generator in Javascript
...334677,s)>>>0)/2**32;
These LCG values are from: P. L'Ecuyer: A table of Linear Congruential Generators of different sizes and good lattice structure, April 30 1997.
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How do I restore a dump file from mysqldump?
...mmand prompt (in Windows) and cd to the directory where the mysql.exe executable is (you may have to look around a bit for it, it'll depend on how you installed mysql, i.e. standalone or as part of a package like WAMP). Once you're in that directory, you should be able to just type the command as I...
What should I do if two libraries provide a function with the same name generating a conflict?
... bit hackish, but all you'd be doing is changing the strings in the symbol table. No real functional harm in that.
– Evan Teran
Mar 24 '09 at 17:52
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What is a correct mime type for docx, pptx etc?
...plication/pkcs8", "plf": "application/vnd.pocketlearn", "pnm": "image/x-portable-anymap", "pbm": "image/x-portable-bitmap", "pcf": "application/x-font-pcf", "pfr": "application/font-tdpfr", "pgn": "application/x-chess-pgn", "pgm": "image/x-portable-graymap", "png": "image/x-png", "ppm": "image/x-por...
Tips for debugging .htaccess rewrite rules
... name="go" value="OK"/><hr/><p>&nbsp;</p>
<table><thead><tr><td><b>Test Vector</b></td><td>&nbsp; &nbsp; <b>Result</b></td>
<?php
for ( $i=0; $i<$maxM; $i++ ) echo "<td>&nbsp; ...
Which is more efficient, a for-each loop, or an iterator?
...n invokeInterface virtual call (go through all the classes, then do method table lookup before the jump).
the implementation of the iterator has to do at least 2 fields lookup in order to make hasNext() call figure the value: #1 get current count and #2 get total count
inside the body loop, there is...
PostgreSQL ERROR: canceling statement due to conflict with recovery
... will be canceled more often.
You can work around this by starting a repeatable read transaction on primary which does a dummy query and then sits idle while a real query is run on secondary. Its presence will prevent vacuuming of old row versions on primary.
More on this subject and other workaro...
HashMap get/put complexity
...answer. Would you please provide links like this wikipedia entry for hash table in your answer? That way, the more interested reader could get to the nitty gritty of understanding why you gave your answer.
– David Weiser
Dec 29 '10 at 15:19
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