[c0nstantine]

Fair point. The most explicit example if you need to change something in context. For example if we need to change 'y' to 'Y' only if it occurs between x and y you would do something like this in python.

pattern = r'(x)y(z)'

replacement = r'\1Y\2'

result = re.sub(pattern, replacement, text)

I would like to replace it with 'xy:Yz' pattern:

result = re.trre('xy:Yz', text)

If you need your x, z to be more complicated patterns or even regex themselves it can be more handy using this approach.

[crazygringo]

Thanks!

I guess I'm still struggling to see how it's simpler overall.

Most of the examples on your page don't involve groups at all, e.g.:

  $ echo 'catcatcat' | trre '((cat):(dog))*'
  dogdogdog

That already seems a lot more complicated than just:

  re.sub('cat', 'dog', 'catcatcat')

I don't need to use groups that often in regex replacements, and when I do I'm already trying to do something complicated, and it's not clear to me why the colon syntax is easier to write, easier to understand, or if it's as flexible.

Not trying to criticize the project, just genuinely trying to understand the specific strengths and limitations of the proposed syntax. E.g. what if I want to turn xyz into zYx?

[c0nstantine]

>> E.g. what if I want to turn xyz into zYx?

echo 'zyx' | ./trre 'xy:Yz|zy:Yx'

It is still a regular language. I do not introduce references.

You are right in sense the `sed` is far superior editor. But here I see some advantages: - the current implementation is super small; it is direct translation to an automaton - the complex patterns may be compiled in a more efficient way using deterministic transducer. I can't defend this claim now but I have some evidences - there are some tricks you can do using 'generative' part of it, e.g. and you even can find levenshtein distance of 1 between two strings just by generating substitutions/insertions/deletions and implement a simple spell checker.

Overall, I think you have a good point. Maybe it is just marginal improvement (if any). It was more comfortable to write in this style instead of group usage. I used it for some time and found it handy (especially as extended `tr`).

[rendaw]

I think it's an interesting project, but is this a functional replacement for regex substitutions? It seems like you can only replace text with something else at the same location. Separating the replacement from the matching can be unweildy, but you can reorder, repeat, and insert text between things too.

IIUC