Basic diff output #238

nc7s · 2023-10-14T21:29:04Z

As proposed in #208 (comment), produce diffs of changes, instead of printing entire files.

This is a rough WIP that copies the terminal-inline example of similar and barely works. I intend to make it produce patches that are actually applicable.

example diff (note that coloring is provided by bat)

CosmicHorrorDev · 2023-10-16T22:55:16Z

Thanks for the PR! I really like how the output looks. I've gone ahead and marked this as a draft while this is still a WIP, but just let me know if you need anything

As for early feedback I think my only concern is that it shouldn't replace the existing output, but should be added as another option. Maybe through a --preview-diff flag or by changing --preview to take take a value like --preview <plain|diff>?

nc7s · 2023-10-17T01:39:40Z

Thanks for the PR! I really like how the output looks. I've gone ahead and marked this as a draft while this is still a WIP, but just let me know if you need anything

Didn't know you can do that ;)

As for early feedback I think my only concern is that it shouldn't replace the existing output, but should be added as another option. Maybe through a --preview-diff flag or by changing --preview to take take a value like --preview <plain|diff>?

Indeed, the word preview has a meaning. Maybe just --diff? Since with such a flag it seems semantically incorrect to overwrite the file anyway.

CosmicHorrorDev · 2023-10-17T01:41:16Z

Sure --diff seems good!

CosmicHorrorDev · 2023-10-22T05:59:21Z

Hmmm, I think I would be all right with that. Just push changes and ping me whenever you want feedback

I am planning on pushing for a release over the next few days

alexilyaev · 2023-12-19T14:30:13Z

Can you share an example of how it would look like?

Got here after searching how to make --preview only show the matched strings or lines that would change and not print the whole file.

Example

This will print every single line of the file and then only at the end prints the change in color.
In large files, this makes --preview unusable.

echo "111\n222\n333\n444\n555\n666\n777\n888\n999" | sd -p '(999)' '000'

So, I'm wondering if the diff mode will help with that scenario?

Similar open issues

I suppose one of these would cover the large file use case as well

nc7s · 2023-12-19T14:42:07Z

Can you share an example of how it would look like?

You can click the triangle on the left of "example" in the topic. Later updates differ a little in detail, but largely it's the same. The Wikipedia entry on diff is probably also worth a read.

Got here after searching how to make --preview only show the matched strings or lines that would change and not print the whole file.

So, I'm wondering if the diff mode will help with that scenario?

Probably. I never thought of diffs in this perspective, but it does work in this way (showing only changes, and limited surrounding context).

alexilyaev · 2023-12-21T10:16:30Z

@nc7s Oh, didn't notice the ▶ next to the example diff ☺️👍🏼
How did you get it to show colors? (I'm on macOS, using Zsh in iTerm)

Ok, so I'm testing -d with a change on consecutive lines and it does show me only the changed lines.
But, it doesn't show me the change for each line, rather a big chunk of "before" lines and then a big chunk of "after" lines:

echo "123\n123\n123\n123\n123\n123\n123\n123\n123\n123\n" | cargo run -- -d '2' '9'

If the changes are not in consecutive line, then it works as expected:

echo "123\n000\n123\n000\n123\n000\n123\n000\n123\n000\n" | cargo run -- -d '2' '9'

I still think that -p should have a flag to show only the affected lines and not print the whole file.

nc7s · 2023-12-21T15:05:17Z

@alexilyaev:

How did you get it to show colors? (I'm on macOS, using Zsh in iTerm)

bat. Now spelled in the <summary>.

Ok, so I'm testing -d with a change on consecutive lines and it does show me only the changed lines. But, it doesn't show me the change for each line, rather a big chunk of "before" lines and then a big chunk of "after" lines:

I still think that -p should have a flag to show only the affected lines and not print the whole file.

This is expected behavior of diffs. Recommended read: https://en.wikipedia.org/wiki/Diff

Sometimes you won't know where and what the changed lines are if no surrounding context is provided. That's why diffs have contexts - to match surrounding lines. They may otherwise update an unrelated but identical line, which is totally possible for short lines of common words.

If you are confident, context radius could be reduced, down to zero. I'm considering an option to set that, but haven't decided on its naming yet.

@CosmicHorrorDev: copied over from earlier, maybe covered in noise:

Although, it lacks a context radius argument. I tend to not use a generic name like --context for a diff. But --diff-context is too long. I also don't know how to name the "file" when input is through stdin, so it's currently empty; maybe the user knows better, so we also provide an argument like --diff-filename?

chmln · 2023-12-23T03:53:51Z

This is great as a prototype, excellent work. I have long wanted to implement something like this.

Not sure if this is actually possible but it would be great if we could integrate one of the rust pagers as a library so that users don't necessarily need to have e.g. bat installed and piped into, to get a nice looking diff output

nc7s · 2023-12-23T03:58:11Z

@chmln:

Not sure if this is actually possible but it would be great if we could integrate one of the rust pagers as a library so that users don't necessarily need to have e.g. bat installed and piped into, to get a nice looking diff output

My thought then was that it feels unnecessary for every CLI program to implement its own colorization, esp. when the output is in a pretty common format. Feels like bloat.

chmln

Minor nits :)

chmln · 2023-12-23T03:56:07Z

src/cli.rs

@@ -20,6 +20,11 @@ pub struct Options {
    /// format are likely to change in the future).
    pub preview: bool,

+    #[arg(short, long)]


I think diff is short enough to not warrant a short flag, -d might be more useful for other things in the future

How about -D? Even sed doesn't have many flags. (I impl'd this after all ;)

And what do you think about an option specifying context radius? And filename for piped diffing?

chmln · 2023-12-23T03:59:10Z

src/diff.rs

+    path: Option<&Path>,
+) -> Result<String> {
+    let diff = TextDiff::from_lines(old.as_ref(), new.as_ref());
+    let path = if let Some(path) = path {


Should just convert to a lossy string here, not sure its worth erroring out. Having the user see squareish symbols is better than not being able to see a diff at all

Indeed when acting as an end user interface, not so when the output is used as a proper diff. Or I'm overestimating the latter use case?

CosmicHorrorDev · 2023-12-23T04:01:09Z

For me the big thing is that an integrated pager can be more aware of its contents. An external pager is usually very naïve when it comes to searching or even determining terminal width

chmln · 2023-12-23T04:07:13Z

My thought then was that it feels unnecessary for every CLI program to implement its own colorization, esp. when the output is in a pretty common format.

That's a valid point, although somewhat more of a philosphical one. Ultimately, the users want to see a pretty diff. If we can make that happen without having them install bat and configure a good looking theme..I think that's a clear win.

And if someone really wants to use their own diff program, we can detect that our diff output is being piped and just produce the raw version as you suggest.

Addendum: nevertheless, shipping this 'raw' diff mode is still a big win for all the power users. Just wanted to provide some ideas and food for thought.

CosmicHorrorDev · 2023-12-23T04:07:19Z

Also sorry for taking so long to give feedback. I've been stretched pretty thin lately. I likely won't have time to take a look till the new year

nc7s · 2023-12-23T12:12:15Z

@CosmicHorrorDev:

For me the big thing is that an integrated pager can be more aware of its contents. An external pager is usually very naïve when it comes to searching or even determining terminal width

I'm no expert in this field, but fear that properly setting up an integrated one requires serious work (you gotta know the ins and outs). Plus, we've already seen GIT_PAGER and QUILT_PAGER, to name a few.

Also sorry for taking so long to give feedback. I've been stretched pretty thin lately. I likely won't have time to take a look till the new year

No worries ;) we all have a bunch of work at year end.

@chmln:

My thought then was that it feels unnecessary for every CLI program to implement its own colorization, esp. when the output is in a pretty common format.

That's a valid point, although somewhat more of a philosphical one. Ultimately, the users want to see a pretty diff. If we can make that happen without having them install bat and configure a good looking theme..I think that's a clear win.

Diff coloring is almost too easy to not implement, certainly can be made to work. The "do one thing" principle sometimes has a vague boundary…

And if someone really wants to use their own diff program, we can detect that our diff output is being piped and just produce the raw version as you suggest.

Yeah, configurable colorization was talked about in #268.

So, combined, maybe we can have colorless diffs first, then implement proper colorization later in one go.

dev-ardi · 2024-01-15T16:46:41Z

Hello @chmln, @nc7s

With @CosmicHorrorDev stepping down what's the status on this? I think it's possitive if either noctis or me would have merge permissions. As I said before don't want to wholely maintain but I wouldn't mind reviewing PRs and doing basic fixes at least until another maintainer shows up.

CosmicHorrorDev marked this pull request as draft October 16, 2023 22:51

CosmicHorrorDev mentioned this pull request Oct 22, 2023

Feature request: Skip line if regex does not match. #164

Open

This comment was marked as resolved.

Sign in to view

nc7s mentioned this pull request Nov 2, 2023

Overall reorganization #265

Merged

nc7s changed the title ~~WIP: diff output for --preview~~ WIP: diff output Nov 3, 2023

nc7s force-pushed the ncts/show-diff branch from 8911d53 to 694f017 Compare November 25, 2023 11:05

This comment was marked as outdated.

Sign in to view

feat: diff view with --diff (-d) flag

e6425e9

nc7s force-pushed the ncts/show-diff branch from 694f017 to e6425e9 Compare November 25, 2023 11:10

nc7s mentioned this pull request Nov 25, 2023

[Feature request] -p preview mode shows a diff of what would happen (with customizable differ) instead of just doing what sed does. #270

Open

fix: use write! for diffs, writeln! produces extraneous lines

320bebd

alexilyaev mentioned this pull request Dec 21, 2023

Flag to only output matched lines #150

Open

chmln reviewed Dec 23, 2023

View reviewed changes

nc7s marked this pull request as ready for review January 17, 2024 22:51

nc7s changed the title ~~WIP: diff output~~ Basic diff output Jan 17, 2024

kanielrkirby mentioned this pull request May 1, 2024

Maintainership, Archive, or Something Else? #298

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Basic diff output #238

Basic diff output #238

nc7s commented Oct 14, 2023 •

edited

CosmicHorrorDev commented Oct 16, 2023

nc7s commented Oct 17, 2023

CosmicHorrorDev commented Oct 17, 2023

This comment was marked as resolved.

CosmicHorrorDev commented Oct 22, 2023

This comment was marked as outdated.

alexilyaev commented Dec 19, 2023

nc7s commented Dec 19, 2023 •

edited

alexilyaev commented Dec 21, 2023

nc7s commented Dec 21, 2023 •

edited

chmln commented Dec 23, 2023 •

edited

nc7s commented Dec 23, 2023

chmln left a comment

chmln Dec 23, 2023

nc7s Dec 23, 2023 •

edited

chmln Dec 23, 2023

nc7s Dec 23, 2023

CosmicHorrorDev commented Dec 23, 2023

chmln commented Dec 23, 2023 •

edited

CosmicHorrorDev commented Dec 23, 2023

nc7s commented Dec 23, 2023

dev-ardi commented Jan 15, 2024

Basic diff output #238

Are you sure you want to change the base?

Basic diff output #238

Conversation

nc7s commented Oct 14, 2023 • edited

CosmicHorrorDev commented Oct 16, 2023

nc7s commented Oct 17, 2023

CosmicHorrorDev commented Oct 17, 2023

This comment was marked as resolved.

CosmicHorrorDev commented Oct 22, 2023

This comment was marked as outdated.

alexilyaev commented Dec 19, 2023

Example

Similar open issues

nc7s commented Dec 19, 2023 • edited

alexilyaev commented Dec 21, 2023

nc7s commented Dec 21, 2023 • edited

chmln commented Dec 23, 2023 • edited

nc7s commented Dec 23, 2023

chmln left a comment

Choose a reason for hiding this comment

chmln Dec 23, 2023

Choose a reason for hiding this comment

nc7s Dec 23, 2023 • edited

Choose a reason for hiding this comment

chmln Dec 23, 2023

Choose a reason for hiding this comment

nc7s Dec 23, 2023

Choose a reason for hiding this comment

CosmicHorrorDev commented Dec 23, 2023

chmln commented Dec 23, 2023 • edited

CosmicHorrorDev commented Dec 23, 2023

nc7s commented Dec 23, 2023

dev-ardi commented Jan 15, 2024

nc7s commented Oct 14, 2023 •

edited

nc7s commented Dec 19, 2023 •

edited

nc7s commented Dec 21, 2023 •

edited

chmln commented Dec 23, 2023 •

edited

nc7s Dec 23, 2023 •

edited

chmln commented Dec 23, 2023 •

edited