Tagged Questions

3
votes
1answer
366 views

Constructing a Deterministic Finite State Automaton for a given Regex

I have a couple of exam questions for my compilers class and wanted to check if my solutions are correct. The first question is: Consider a language in which numbers start with an optional minus ...
5
votes
2answers
220 views

Python flavor of regular expressions - related to which?

So my copy of the classic book, Mastering Regular Expressions, just arrived, and I'm scanning through it. The cover (third edition) says, "for Perl, PHP, Java, .NET, Ruby, and More!" Well, it does ...
8
votes
7answers
2k views

How do regular expressions actually work?

Say you have a document with an essay written. You want to parse this essay to only select certain words. Cool. Is using a regular expression faster than parsing the file line by line and word by ...
13
votes
10answers
717 views

Inspiring problems to show off the importance of regular expressions?

I am planning to give a presentation/demonstration on regular expressions at work to encourage young developers to add this powerful and important tool in their toolbox. Just teaching syntax doesn't ...
77
votes
18answers
4k views

How do you learn Regular Expressions?

I'm not asking where to learn. I've found lots of good resources online, and books etc. But how the heck do I tackle them. Where is the start of it, the end? When does the regexp processor advance on ...
12
votes
6answers
394 views

What can / should be done with regular expressions?

I've recently learnt regular expressions and I love writing / using them. I'm looking for ideas and more opportunities to use them, however I don't want to overuse them as an all purpose tool, as ...
3
votes
1answer
642 views

can a regex search engine for the web be done and if so, how?

I think it would be a great idea if we had a regular expression search engine, but can it be done? It seems impossible since there's no feasible way of indexing such a huge amount of data properly and ...
0
votes
2answers
224 views

Regexp or custom parsing algo?

I was trying to parse a java properties file to avoid some Properties loading pitfalls (non ordering, loss of comments). (Property are of the form 'key = value' where the value can span on multiple ...