How to make a list out of regex

Question

0.00/5 (No votes)

See more:

Hello.
I have a simple string which looks like this:

C#

string test = "token1 token2 token3 complex token";

I need to split this string into tokens with regex. Token names are always the same, but can be lets say: token4, token5, complex token2, etc.

What I have tried:

What I have tried to do is the following:

C#

var result = Regex.Matches(test, "(token1) (token2) (complex token)").Cast<Match>().Select(m => m.Value).ToList()

This does not work. List is either empty, or contain one string which is a collection of all tokens, like this: token1 token2 complex token. But I need it to contain for this case, 3 strings, each one will be the token.
Can someone help please?
Regards

Posted 5-Feb-20 12:25pm

csrss

Updated 6-Feb-20 3:34am

Add a Solution

2 solutions

Solution 1

you need a tokenizer i think.

At the risk of plugging my own offerings try this: Rolex (Reboot): Unicode Enabled Lexer Generator in C#[^]

// rolex lex spec
complexToken = 'complex token[0-9]+'
token = '[A-Za-z][A-Za-z0-9]*'
int = '\-?[0-9]*' // just an example
ws<hidden> = '[ \t]+' // hide whitespace

Then you can tokenize by doing this

C#

foreach(var token in new MyTokenizer("my test string"))
   Console.WriteLine("{0}: {1} at {2}",tok.SymbolId,tok.Value,tok.Position)

It creates a single file with no dependendecies. Input is IEnumerable<char>, "output" is IEnumerable<Token>

if you need that over a file, use this IO: A Small Streaming I/O and UTF-32 Library[^]

Posted 5-Feb-20 14:46pm

honey the codewitch

Updated 5-Feb-20 15:03pm

v7

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2020-02-06T03:35:00

Your regex will only match the literal string "token 1 token 2 complex token". You'll only get multiple matches if your input string contains that literal string multiple times.

Assuming you just want to extract the individual tokens, try:

C#

var result = Regex.Matches(test, @"(token1)|(token2)|(complex token)").Cast<Match>().Select(m => m.Value).ToList();

Regular Expression Language - Quick Reference | Microsoft Docs[^]