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
242
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
12
votes
2
answers
3k
views
Designing a Python string validation library
My employer has a significant number of company-internal strings which require format validation. For instance, order number AAA-BBB-CCC, stock number AB-123456 or factory ABC1 - Regex with extras (...
- 571
1
vote
1
answer
952
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
31
votes
6
answers
13k
views
Is exposing regex in error response to end user bad practice?
Say I have a have request payload
PUT /user
{
email: "invalid"
...
}
In the backend there is a email regex, which I cannot modify. Currently the behavior is to output:
{
"error&...
- 427
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
0
votes
0
answers
177
views
Domain specific language for regex processing
I am working on a DSL for text processing. The core is searching for regular expressions with some operators around them. These searches are embedded into a more procedural program, which allows for ...
- 237
-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
3
votes
3
answers
3k
views
What is the right algorithm to match regex on a stream?
I'd like to match a regex pattern on a stream, but I am not sure what algorithm to use. I certainly don't want to load the entire file into memory.
I tried to figure out how to do this, but I have ...
- 1,259
-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
0
votes
1
answer
67
views
portable hashable string representation of data object
I have a class of (flat) objects that are going to be passed around between three different parties, each possibly running a different software stack.
my_object:
item: "string_a"
money:
...
- 414
1
vote
1
answer
306
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
2
votes
4
answers
3k
views
What is the optimal way to perform 5000 unique string replace functions in terms of performance?
Restructuring some code, and the way I built it up over time has portions that look something like this:
s.replace("ABW"," Aruba ");
s.replace("AFG"," Afghanistan ");
s.replace("AGO"," Angola ");
s....
- 3,649
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
3
votes
1
answer
211
views
Why are `]` and `}` not metacharacters in Regex when ')' is?
In Regular Expressions Quick Start, it reads
Twelve characters have special meanings in regular expressions: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or ...
- 167
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