Questions tagged [regular-expressions]
According to Wikipedia, a regular expression (abbreviated regex or regexp) is a sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations.
91 questions
1 vote
4 answers
238 views
Programming language independent semantic validation of message protocol
I have a proprietary protocol that describes the exchange of messages of two participants (applications) via a messaging broker (mqtt). A participant is of type A or B. Each type is allowed to send ...
- 29
1 vote
1 answer
935 views
How to implement a RegEx library in C [closed]
Background I have been attempting to create a line editor in C, eventually becoming a visual editor, and as a means of both allowing the editor to be useful but also learn more about C development, I ...
- 19
1 vote
2 answers
5k views
Alternative to using regex in Python
Background I do programming with Python and now and then i run into a situation where i have to use regex Typically i try to learn a bit about it and look at examples of doing things similar to what i'...
- 477
-5 votes
1 answer
1k views
In what programming language is Python's regex module written in? [closed]
If I try to rewrite specific regex functionalities (e.g. substituting a string) in Python, a solution using the regex module is always faster. Is regex written in C?
- 93
-4 votes
1 answer
3k views
What is the best use case of a regular expression (TripleByte question)?
I have lots of experience with regexes. I just want to make sense of this. Am I missing something here. Which one of these would you rather validate with a regex? Question reads, Which of the ...
- 113
1 vote
1 answer
305 views
Is it possible to create a regular language from an non regular language?
I am wondering if it is possible to create a regular language from a irregular language if we add or remove finite number of words from it? say L is irregular, can we add or remove finite number of ...
- 33
1 vote
1 answer
4k views
Is it a good practice to include empty/white space checks in RegEx?
The goal of the RegEx is to match exactly 6 characters, but in addition it should match empty strings or white space (e.g: ^$|\s|^(\w){6}$). Is it good practice check for empty string/white space in a ...
- 157
9 votes
4 answers
507 views
Guarding user input of regular expressions against attacks
I am aware of Regular Expression Denial of Service (ReDoS). Is there any reasonable way to allow users to create custom regexes while guaranteeing that they don't submit an exponentially slow pattern?
- 429