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menthena
how do you do

great work, bookmarked.

"Share doc" is not clear imo. Why not "Save & Share"?

ivolimmen
This looks really useful for a quick calculation. Thanks for the bookmark!
ttoinou
Nice. Could this be done with a VS Code extension ?
tonyonodi
I've never made a VS Code extension, but I think it would be possible; no plans to do so currently though.
nudpiedo
there are several inline repl extensions, for many many programming languages. One of the first ones to do it was clojure, imitating the lighttable IDE. I believe you will find similar ones for other languages
elcritch
Looks nice! Making the result blocks non-text is handy. Any plans to open source this or sell a desktop version? I've long been a fan of http://calca.io but it doesn't run on Linux. There's some other versions out there but they tend to be flaky.
tonyonodi
Glad you like it! I've got a desktop version in the works, and if the web version gets enough interest I'll finish it off.
Aeolun
Finish it off sounds like you are going to kill it ;)
nudpiedo
Why limit it to arithmetic?

Looks much like the original idea behind lighttable IDE which is basically a REPL plugin that allows to evaluate certain lines within it. There are several similar projects around.

tonyonodi
Because Turing completeness scares me!

I was a big fan of Light Table when it first came out and the developers behind it have gone on to do some really interesting things, but I want to keep this project more limited in scope for now.

nudpiedo
Coding comes with the implicit responsibility over one’s mess. Everyone understands that hanging your computer for your own actions it’s own’s fault.

That can be an issue if you provide a limitless cloud instance, but you can roll the ball to user’s roof with client a side engine, either JS or a local instance, depending your vision for such an app.

nonoesp
I have a side project slightly similar to the functionality your tool offers focused on expense tracking (or other measures) over time, adding date parsing to the equation in order to plot metrics into a graph and with tags and locations for filtering.
tonyonodi
Nice! Can you send a link or is it still in development?
nonoesp
Hey!

It's still in development. I built a proof-of-concept from scratch almost a year ago, which I just open-sourced at the following link.

https://github.com/nonoesp/note-parser

I intend to develop it a bit more and host it online.

A previous prototype, really barebones, is at https://expensed.me.

The idea is to drag and drop (or type) a plain-text note and visualize the data as a scatterplot or other charts.

Dries007
I'm (slowly) working on something that can eat up PSD2 data from banks and parse it into some usable data, but I'm bad at nicely presenting stuff. It would be great to see your tool and get some inspiration, or maybe even use it.
nonoesp
This sounds super interesting.

I've been thinking of ways to parser phone screenshots with payment data or use bank APIs to add data to my expense tracker, as opposed to adding everything manually, which is the best way I've found for consistency and to make sure everything is properly formatted.

I didn't know about PSD2. Do you have any links or references for me to look at?

tiagod
Hey, great tool!

Just a little bug: I found that if I click a number to copy, then click it again, I'll get the original string in my clipboard concatenated with " Copied!"

tonyonodi
Glad you like it! Thank you for the bug report, I'll get it fixed shortly
adamddev1
I like this! One thing that would be nice is a time zone converter. For example:

8:00pm 24 Aug Toronto time in Dubai time

And have the conversion show up.

owl110
Looks very interesting. I think there is some ambiguity with respect to currency symbols, $ converts to USD and £ to GBP. However, depending on user location those symbols can be used to mean very different currencies.
tonyonodi
Is there anywhere else that uses "£"? I didn't feel great about having $ default to USD but it is probably what most users want. I'll probably make it location-aware and/or allow the user to decide which it defaults to in the future.
defrost
Nice - I'll give it props for:

> 1 metre + 8 chain = 161.9344 m

> 1 tonne + 1 short ton = 1.90718474 t

> 1 tonne + 1 long ton = 2.0160469 t

and give it a pass for not supporting pre 1963 UK | US historic weights and measures .. that's getting into a pretty specific use case where Standards nerds like to have a clear display of what conversion factors are in play and what provenance those factors have.

Time Zone support (on your About ToDo) will be interesting, historic computations with daytime savings support will be a quagmnire :-)

The SHARE DOC URLs seem a bit long - something like "base64 full text of doc as an URL" I guess.

Will this hit a URL length limit if widespread use becomes a thing?

jq play : https://jqplay.org/s/f1r-BZ5xYd2

regex101 : https://regex101.com/r/OqojJl/1

do server side storage and doc hash .. which has issues of its own.

tonyonodi
Well, I love this comment. And yes, time zone support terrifies me an order of magnitude more than anything else on the list.
defrost
On the gnarly scale dealing with with pre-WGS84 paper maps from about the globe is arguably worse ..

there are so many reference ellipsoids and datums used in different parts of the world at different times .. and then there are the many variations on curved surface to flat map projections to deal with.

But yes - Time and date is an iceberg domain :-)

tonyonodi
You're right, I'm using lz-string to compress the text before shoving it in the URL. This is definitely a necessary evil for the time being so I don't need a back end component to the app. But eventually I do want prettier URLs and collaborative editing if I can make that work without it bankrupting me or driving me insane.
simonz05
Be aware URL field in browsers have a maximum number of characters they accept.
dunham
For what it's worth, the typescript playground takes the exact same approach as you, placing a compressed (lz-string) copy of the text after the #code/ in a sharing url.
amelius
For the next step, maybe you can build an editor/autocomplete with a search-engine in it (you can use an existing search engine).
jackphilson
how expensive was that domain name lol
tonyonodi
I'm just paying the standard fee for a .io, it's a far less polluted namespace than .com :)
spiffytech
Very cool!

This reminds me of the open source NoteCalc: https://bbodi.github.io/notecalc3/

It was discussed on HN, you might look there for inspiration: https://news.ycombinator.com/item?id=25495393

tonyonodi
I hadn't seen that before, it's very impressive!
bbodi
I am the author of NoteCalc, and it warms my heart that my project is mentioned here :)

As a sidenote I would like to mention that NoteCalc is still in active (but slow) development, though I do it privately, and the next big release will be definitely this year.

mad2021
Just discovered NoteCalc, really cool. Thanks!
zwog
When I type `4W*3hours` the result is `12 mWh`. Same with `12Wh/3hours = 4kW`
tonyonodi
Oh, thank you for the bug report. I'm not sure why that's happening, but will look into it shortly.
sandgiant
This is great! Love Soulver too, but having it in the browser is fantastic. Well done!
tonyonodi
I'm a big fan of Soulver too! It's the OG in this app category and I still use it for calculations NumPad can't do (yet!).
bkazez
Very cool! Some ideas:

1. Doesn't seem to support area conversions (tried 400 square meters, 400 m^2, and abbreviations in between).

2. If I only give a time, it would be more useful if it gave a time-only result rather than defaulting to the current date - unless it rolls over to a different date. (E.g. in Soulver, "2:30pm + 20hr" gives "Tomorrow at 10:30".)

3. It would be nice to support multiple abbreviations for minutes (mn/min are both used in various countries).

zweifuss
400 inch^2 -> 400 inches² 10 km^2 -> 10 km²

... works for me.

bkazez
Ohhh, I missed that "->" was the operator. I was typing "to" as in Google searches.

Re dateless times, yes, I think the Soulver way is unambiguous but still human-friendly.

tonyonodi
Thanks for the feedback

1. "square" before a unit I probably will implement that in the future. I'm not sure why "400 m^2" isn't working for you, I've just tried it and it works as expected for me?

2. It's a little bit clunky, but I decided to always specify the time and date being shown because there's so much potential for ambiguity. I might revisit this if I can think of a better way of doing it that's still unambiguous (the Soulver way isn't bad tbh)

3. "min" is supported, I've never come across "mn", do you know where it's used?

seper8
Love it! This kind of stuff should be added to notepad on Windows (in an opt-in manner)!
imagine99
IIRC, calc.exe (Windows Calculator) has some (limited) unit conversions built in. Better than nothing in an offline environment...
vhanda
This is awesome.

Minor bug report -

* 5 feet 8 inches to centimeters -> -171.72 cm

* 5 feet 8 inches to meters -> -0.7272 m

* 5 feet 8 inches to cms -> doesn't work

The conversion seems wrong in the case of cms, and I'm not sure why it's always negative.

defrost
"to" is a subtraction operation, not a convert to cue.

As in (distance from) 30 to 50 (is 20 == 50 - 30 )

Spare_account
After reading the sibling comments to mine, I've worked out what it is doing.

> * 5 feet 8 inches to centimeters -> -171.72 cm

As @defrost said, the 'to' operator instructs NumPad to calculate the distance from the unit before 'to' and the unit after 'to'.

To the nearest mm, 5 feet 8 inches = 172.72cm

It appears that NumPad is defaulting to a value of '1' where no value is specified, so it is calcuating the distance BACK from '5 feet 8 inches' TO '1 centimeters'.

It correctly responds with -171.72, which is 1cm less than 172.72.

> * 5 feet 8 inches to meters -> -0.7272 m

Same as above, except the calucation is the distance back from '5 feet 8 inches' TO '1 metres'.*

If you use the operator 'in', NumPad calculates the answer correctly:

5 feet 8 inches in metres -> 1.7272 m

shreyshnaccount
THIS IS AMAZING. the next step is adding variables and assignments and conditionals, and you have something very powerful that can be used by just about anybody to do really interesting things. provided you have a way to integrate with other services that a lot of people use
janjones
Variables and assignments are already supported.
shreyshnaccount
should rephrase, meant to say (variables, assignments) AND conditionals
tonyonodi
Thanks! Turning the current language into a Turing complete one would be a huge step up in complexity and I'm not sure it will ever make sense to implement. But I have thought about adding the ability for users to define their own functions in JS and might get around to that one day.
shreyshnaccount
I see. despite my not totally unjustified hate of Javascript, Im looking forward to it.
sjinta
This is awesome! Some feature requests: it would be great though if you could have multiple sessions/tabs in stead of 1. Also a clear button would be nice.
mrcartmeneses
Can’t you just select all then hit backspace? Asking for a friend...
sjinta
When using it to make simple calculations while on a phone I think it would be easier than the long click select all delete combo, but perhaps this is not really the aim of the tool.
brospars
There is something wrong with the order of operations. When I type 2+2*2-6 i get -6 which should be 0.
unsafecast
It looks like APL order? Right-to-left.
JackFr
No. It’s not right to left. It’s just weird:

  3 ^ 1 * 2   6
  3 ^ 1 / 2   1.73205
  3 ^ 1 + 2   5
  3 ^ 1 - 2   1
sneak
I would think this might be the first unit test one would write for a calculator program.
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bdwjn
Oh there's more:

9 - 3 ^ 2 = 0

9 -3 ^ 2 = 18 ???

pi = 3.1415926536

2 pi = 5.1415926536 ???

sin(3.1415926536 radians) = -0

sin(pi radians) = Incompatible units ???

wizofaus
Seems to assume + if an arithmetic operator is missing?
tonyonodi
This is correct, the idea is that you can type things like "6 foot 3 inches" and have it evaluate as an addition. But the example shown above is definitely a problem, I'll try to think of a work around.
wizofaus
I'd think that rule only makes sense after a symbol representing a unit (including potentially 6'3"). Certainly <number> <named constant> should logically assume multiplication.
simonz05
Yep, this should be evaluated as `(- (+ 2 (* 2 2)) 6)`
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OJFord
This is great, I use `bc` a lot at work (particularly when away from desk and my actual calculator) but I'll probably bookmark this to use instead.

One bit of very minor feedback:

`x^y tonnes` errors 'exponent must be unitless'. The more expected (IMO) grouping `(x^y) tonnes` works, so why not have the non-error grouping be the implied one, when no parens given?

tonyonodi
I hadn't thought about that before but I think you're right, I've added it to my roadmap.

Getting operator precedence right has been pretty fraught tbh. For example "1km / 3 hours" is evaluated as "(1km) / (3 hours)", but "1 / 3 hours" is evaluated as "(1 / 3) hours", which is odd from a PL perspective, but I think it's more intuitive from a user perspective for this sort of thing.