
Ask HN: Why not edit all code in 'diff' view? - smrtinsert
70% of coding is maintenance.  Often you are replacing logic that might still be relevant, but requires a tweak.  Why not show a live diff as you work?  This keeps you in context without forcing you to comment out or write &#x27;parallel&#x27; code.
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hon
Xcode has this except it's called Comparison view. It's one of the things I
love about working in Xcode.

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gus_massa
With some google search I got this screenshots for the Comparison view in
Xcode.

[http://stackoverflow.com/questions/6013458/how-to-set-up-
fil...](http://stackoverflow.com/questions/6013458/how-to-set-up-file-compare-
diff-in-xcode-4)

It has even some git integration.

[http://www.appcoda.com/git-source-control-in-
xcode/](http://www.appcoda.com/git-source-control-in-xcode/)

[https://aimatters.wordpress.com/2016/05/25/using-xcode-
with-...](https://aimatters.wordpress.com/2016/05/25/using-xcode-with-github/)

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z1mm32m4n
In addition to the other tools people have mentioned, Vim supports this with
tpope's vim-fugitive (:Gdiff)

To answer your question, "... why not?":

* oftentimes when I'm writing code I'd rather split the screen with another relevant file

* sometimes the diff is irrelevant (I started from scratch, or primarily added code instead of modifying or removing it)

* other times, it's enough to know only that a line has changed. I've configured Vim (with vim-git-gutter) to show symbols next to added and removed lines

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twitchard
If you tdd, you will write the test for the new code while the old code is
still available, and you will use the test as a guide rather than the old
code.

Even if you don't tdd, I would say that typically if you understand the code
well enough to make a change, you should be able to write a replacement
without referring to the old code. The diff should fit in your mind, so to
speak. There are some exceptions, like when you're modifying a regex or some
dense, opaque shell command, but in the course of modifying typical code I
can't see a live diff being that useful to me

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tedmiston
I constantly reference the Tower ([https://www.git-
tower.com/mac/](https://www.git-tower.com/mac/)) current diff view while
coding a new feature or hotfix. It would be awesome to have that level of
integration in Sublime. GitGutter is a great add-on package but way more
limited in scope.

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miguelrochefort
All IDEs provide that...

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jaimex2
my thoughts exactly.

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gus_massa
Looks like a nice idea. I'd like an option to toggle between normal view and
diff view. Perhaps you can write a plugin for your favorite text editor.

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ajeet_dhaliwal
It's easy enough to diff and un-diff and I'd rather have the full window while
editing, especially on a laptop.

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itamarst
Anyone know of version of this for emacs?

