Comment by mrb | Hacker News Reader

Comment by mrb | Hacker News Reader

What I want is a phone app calculator that works like the Python REPL/console. Save ALL previous calculations. Display the last dozen or so. Can scroll through them. Tap on one to recall it, edit one number, recompute. Done.

This would beat by far the convenience and usability of this 2-in-1 calculator. I would KILL to have this.

In fact, on my laptop, I use the Python REPL as a calculator. I hit Ctrl-T python ENTER. It opens a terminal and I start typing 48*152 ENTER and I see the result. The history of calculations is saved. I can access previous calculations, edit one number and recompute. I see the last 100 lines or so, on one screen.

The only one somewhat usable Python REPL on Android is "Pyonic Python 3 interpreter" but it's clumsy to use as a calculator because it uses the standard alphabetic keyboard so you have to keep switching to the special characters layout to type math operators (-+/...) If this ONE detail would be fixed, and with some minor UI polish I believe it could become more popular than the 2-in-1 calculator...

Exactly! I created calculator app with history for this reason. It also allows you to copy and paste from past results.

- iOS: https://apps.apple.com/us/app/instant-calculator/id163232882... - Android: https://play.google.com/store/apps/details?id=com.adrianmeji...

I've been using an app called Calctape[0] for years that sounds similar to what you're describing.

It's essentially a 4-function calculator that records every step on tape, but you can edit any digit anywhere and all related steps are immediately recalculated, like on a spreadsheet.

[0] https://calctape.app/

Interesting. Not exactly what I described though (sorry I did not explain very well.) What I meant, you type 2 calculations:

Then if you tap the first line ("1+1") my ideal REPL would add it to the bottom:

  > 1+1
  2
  > 10+10
  20
  > 1+1_ (with the cursor here ready to edit it)

Then you can for examlpe change a 1 to 2, then type ENTER:

That way you can easily compute a few things, then compare both the expressions and results of the last few calculations, and quickly make edits/corrections as needed.

I've been using All-In-One Calculator (https://play.google.com/store/apps/details?id=all.in.one.cal...) for years, mostly because of all the conversions it can do. It has what you want, although you need to clear the result before tapping a previous calculation, otherwise it appends the formula to the result (e.g. in your example, you would get 201+1).

qalc (https://github.com/Qalculate/libqalculate) is my command-line calculator of choice. Its killer feature IMO is the units support

Very cool ! For units conversion I use GNU Units. But qalc seems to combine the benefits of both the Python REPL and GNU Units. I just tried the command-line version and noticed it doesn't support recalling the history (UP arrow) and editing calculations. This is unfortunately a deal-breaker :-( Don't have time to submit a patch.

It does! Via readline. There must be a problem with your build.

Also, you can get this functionality for even your broken build (or other interactive commandline apps that have no edit history) by just doing something like:

    alias qalc='rlrwap qalc'

Ah, i must not have compiled it with libreadline-dev... And I didn't know about rlwrap!

http://tydligapp.com/ sounds like what you might be looking for.

If you know an APL-like or are willing to learn enough to use as a calculator (there are unfortunately some uncommon things like % being division), there's J on iOS: https://apps.apple.com/us/app/j901/id1483497239. There ought to be a way to get it on Android.

I have an older version of it and it works fine although the keyboard is a little clunky. However, you need to swipe to get to previous computations. I'm not sure if they changed that in the new version.

The built in Android calculator worked like this for ages and it keeps history forever.

The built-in calc sucks: when the keyboard is displayed to edit the current expression, the app can only display ONE previous expression at a time. Sometimes I calculate things and need to refer to 2 or more previous results. I would have to copy paste them one at a time (cumbersome) or memorize them.

If only it could display about a dozen previous results while the keyboard is active... With a Python REPL I can just assign intermediate results to variables.

Reply on news.ycombinator.com