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Please explain some of Paul Graham's points on Lisp
...is useful to have a clear picture of what happens with Lisp code -- in the form of a stream of characters typed in by the programmer -- on its way to being executed. Let's use a concrete example:
;; a library import for completeness,
;; we won't concern ourselves with it
(require '[clojure.contrib.s...
MySQL stored procedure vs function, which would I use when?
...oes not return a value. Instead, it is invoked with a CALL statement to perform an operation such as modifying a table or processing retrieved records.
A function is invoked within an expression and returns a single value directly to the caller to be used in the expression.
You cannot invoke a funct...
How to avoid isset() and empty()
... have expanded this topic into a small article, which provides the below information in a somewhat better structured form: The Definitive Guide To PHP's isset And empty
IMHO you should think about not just making the app "E_NOTICE compatible", but restructuring the whole thing. Having hundreds of...
Proper SCSS Asset Structure in Rails
...ding.scss";
// Styled patterns and elements
@import "type.scss";
@import "forms.scss";
@import "tables.scss";
@import "patterns.scss";
And your application.scss file look like:
@import "bootstrap/bootstrap.scss";
Because of the order of the imports, you can now use the variables, loaded with @...
Why are joins bad when considering scalability?
...ed. And the only way you can truly judge "failure" is to set meaningful performance goals and measure against those goals. If you haven't measured, it's too soon to even think about de-normalization.
* That is, exist as entities distinct from mere collections of tables. An additional reason for a r...
Difference between a “coroutine” and a “thread”?
...
Coroutines are a form of sequential processing: only one is executing at any given time (just like subroutines AKA procedures AKA functions -- they just pass the baton among each other more fluidly).
Threads are (at least conceptually) a f...
How do HTML parses work if they're not using regexp?
...
Regular expressions are just one form of parser. An honest-to-goodness HTML parser will be significantly more complicated than can be expressed in regexes, using recursive descent, prediction, and several other techniques to properly interpret the text. If y...
What Does 'Then' Really Mean in CasperJS
I'm using CasperJS to automate a series of clicks, completed forms, parsing data, etc through a website.
3 Answers
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Why is lock(this) {…} bad?
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It is bad form to use this in lock statements because it is generally out of your control who else might be locking on that object.
In order to properly plan parallel operations, special care should be taken to consider possible deadl...
Can I have an IF block in DOS batch file?
... his problem. I was simply posting an example of the proper syntax. Either form is acceptable in this case, just as would be if 0 == 0 or any other trivial expression. But indeed, make sure that you understand the difference between the environment variable %ERRORLEVEL% and the internal ERRORLEVEL o...