The page I am working on has a javascript function executed to print parts of the page. For some reason, printing in Safari, causes the window to somehow update. I say somehow, because it does not really refresh as in reload the page, but rather it starts the "rendering" of the page from start, i.e. scroll to top, flash animations start from 0, and so forth. The effect is reproduced by this fiddle: http://jsfiddle.net/fYmnB/ Clicking the print button and finishing or cancelling a print in Safari causes the screen to "go white" for a sec, which in my real website manifests itself as something "like" a reload. While running print button with, let's say, Firefox, just opens and closes the print dialogue without affecting the fiddle page in any way. Is there something with my way of calling the browsers print method that causes this, or how can it be explained - and preferably, avoided? P.S.: On my real site the same occurs with Chrome. In the ex
Your question is kind of ambiguous to me: You must define what you mean with Universal, but here's my answer:
ReplyDeleteRegular Expressions are used in almost every programming language like PHP, JavaScript, Perl, Awk, Java, C#, etc...
The thing is that the syntax may vary a little bit from one language to another, and each language may implement them in a different way, and include or not some particular features (usually features that allow regex to recognize not only regular languages, but also others like Context-Free ones)
If you create a new programming language, you can add them regexes feature, but that doesn't mean the syntax will be exactly the same as regexes syntax in .NET, for example. And not only that: The implementation of the engine will surely be different (more/less efficient) than others...
They're not all exactly the same
ReplyDeleteTake a look at this list for some of the differences
No. There are many dialects of regular expressions, though the basic expressions tend to be quite similar. Also, a useful feature introduced in one dialect is often copied by other dialects.
ReplyDeleteRegular expressions in themselves are a programming construct. So you'll find that the core concepts regarding expressions for pattern matching are basically universal, however each implementation will provide their specific spin on the syntax to go about accomplishing that.
ReplyDeleteNo. But anything you are likely to use will support them in some shape or form.
ReplyDeleteThe bad news is no!
ReplyDeleteThere are many implementations and variations of regexes.
In a standard unix implementation ksh, bash, grep and awk all use slightly different rules. lua has a very limited regex library and Java has a fully functioning lib but with its own quirks.
The good news is that most of the popular scripting (php, python etc.) languages use "pcre" library and as "pcre" stands for "Perl Compatable Regular Expresions" by definition it works the same as perl regular expressions as far as possible. And the pcre library is linkable from to compiled languages (C,C++ etc).