Super cool. I wish this was open source so I could see how you did some things, but I understand you've decided to keep it closed. Just to satisfy my curiosity, would you mind sharing how you did parsing at a high level? Did you use some publicly available parser/lexer or did you just implement pattern matching yourself with something like regex or other token splitting measures?
Show HN: I made a web-based notepad with a built in unit calculator
161–170 of 246 posts
Re: Show HN: I made a web-based notepad with a built in unit calculator
#162This is really cool.
I usually end up doing some weird math during development and I usually use the browser developer tools which is a bit cumbersome.
This might help me replace it.
Re: Show HN: I made a web-based notepad with a built in unit calculator
#163Very cool! Any plans to support vector/matrix operations? I occasionally do some work with 2D/3D graphics or physics and having some basic linalg would be nice.
I can see myself using this a lot as a scratch pad to hash out ideas while implementing stuff. The ability to define custom functions would be very helpful for that.
Re: Show HN: I made a web-based notepad with a built in unit calculator
#164Super cool. I wish this was open source so I could see how you did some things, but I understand you've decided to keep it closed. Just to satisfy my curiosity, would you mind sharing how you did parsing at a high level? Did you use some publicly available parser/lexer or did you just implement pattern matching yourself with something like regex or other token splitting measures?
I've found that a super simple way to parse basic expressions is a recursive descent parser. It is very simple to implement. No need to to break into tokenizer/parser, no need to generate an AST, just evaluate the expression while parsing.
Re: Show HN: I made a web-based notepad with a built in unit calculator
#165Along the same lines, I made a command line calculator that does basic unit conversions, and has a few other tricks up it's sleeve https://github.com/seligman/human_calc I find it surprisingly useful. It's probably one of those things that has an audience of one, but I find it useful.
This is really cool, you're a braver person than I for tackling the English representation of numbers stuff!
Re: Show HN: I made a web-based notepad with a built in unit calculator
#1662+2*2-3 calculated as 0. WAT?
Re: Show HN: I made a web-based notepad with a built in unit calculator
#167I like how you are using a Gist for the exchange rates ( https://gist.github.com/tonyonodi/e154f529180b1f0f475966d333... ), do you have a GitHub action setup to automatically update that?
Impressed you found that. I don't have anything set up to automatically update it currently, but I do have an intention to have something set up to automatically update it.
Ha, yes, I was being nosy. It was quite easy to spot as it's the only XHR/Fetch request.
I was intrigued what you had used to build it, and if you had built your own solver (which you have), and what editor you used (Code Mirror) so went looking at the code. Interesting to see you left the source maps for production, made it easy for my sleuthing...
I experimented with a similar idea last year, but used ProseMirror/TipTap as the editor to enable rich text editing, and the MathJS (https://mathjs.org) solver. I also combined it with PouchDB and Yjs for offline editing and syncing between devices. Never finished it though, you have kept your nice and simple!
Re: Show HN: I made a web-based notepad with a built in unit calculator
#168This looks pretty cool. I've long been looking for something similar to Soulver ( https://soulver.app/ ) that I can use on Linux. This seems promising. One small criticism: In my opinion, no web-based writing app is useful unless the tab key inserts a tab. The default behavior of most browsers to move focus to the next field is tremendously infuriating in this context. Unfortunately, that's what happens here, at leas…
Might not be as comprehensive as Soulver, but here's something I've been using in a browser to fiddle with: https://cruncher.io/ .
> Cruncher can also automatically plot changes as you adjust a variable
Well that's pretty neat. I've seen it in fancier setups, but not something Soulver-like. It seems a lot more usable here, since practically any equation can show it.
Re: Show HN: I made a web-based notepad with a built in unit calculator
#1692+2 -> 4 ok
2+22 -> 6 ok
2+22-3 -> 0 What?
Re: Show HN: I made a web-based notepad with a built in unit calculator
#170Maybe there's already a way to do this, but it seems to me that it would be useful to be able to refer to the answer on a previous line, like the Ans key on a TI calculator. So:
2 + 3 (=4)
Ans * 2 (=8)