Mesh Spreadsheet

What is Mesh?

Mesh is a JavaScript code editor that feels like a spreadsheet.

It runs in a browser (but doesn't require internet) and can be carried with you on a USB. It:

• uses JavaScript as its formula language, and stores sheet files as JavaScript source code
• is lightweight: ~2000 lines of source code (excluding libraries)
• has no install or privacy headaches
• strives for maximum compatibility: runs in Internet Explorer 11+ and is based on ECMAScript 5
• is free (as in beer), open-source and permissively licensed (Apache 2.0).

Mesh is really a 'user experience' layer on top of the JavaScript that's built into browsers.

How do I use Mesh?

Download it here or try it out here (takes a couple of seconds to load). Here's the user guide.

Mesh emphasises structured data (arrays, tables, etc) more than Excel and Google Sheets, which can take getting used to.

Why may I want to use Mesh instead of...

Excel or Google Docs?

Aside from being free, with Mesh you can:

• work with data of arbitrary length (including changing the row count of tables at calculation time)
• compare spreadsheets using standard tools such as Word's 'compare docs', or 'diff' them at the command prompt
• integrate sheets within websites, as calculation engines
• manage sheets with the rest of your code base using your existing version control tools (they're just text files)
• use and write custom themes (using CSS).

Libre Office?

Mesh fits into <1MB, so it has a much smaller download size. Also, it has a different feature mix.

I'd like to think that Mesh's code base is small enough that anyone can read it and be ready to contribute within an hour or two.

A 'real' programming language?

You can write real programs in a spreadsheet! For example, here's what Mesh's own code looks like.

Writing code in a spreadsheet format provides you with immediate feedback and lets you lay out your program on a 2D canvas. I highly recommend trying it.

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Roadmap

Alpha

• Allow loading and saving
• Anonymous-first. Make it so you don't need to name data to enter it. Right now empty cells generate names, will that change?
• Any code layout changes.
  • Remove _OUTPUT and just add props via code to cells?
  • Figure out whether managing locations and other props in a separate object
• Docs:
  • Create short tutorial of how to use and when better than Excel, Google Sheets, etc. [shortcut list]
  • Update README, including better-sized GIFs that show off the features, and interop (messaging)
  • Libraries (and how to "import" and use without a build process)
• Flush out any remaining cache logic issues, eg:
  • Don't recalculate if the cell's a primitive value and it didn't change
  • Let's say we override b, then we send in new data in a subsequent recalc. Should b now return to normal?
  • What if a cell happens to recalc to the same value as before? Should we not invalidate its calc chain from that point?
  • Deleting names has a bug
• Add Mesh to Product Hunt and this free office suite list and other 'self-hosted' app lists
• Cleanup:
  • Figure out whether need to add Apache license to each source file? (+ remove NOTICE?)
  • Update boilerplate with latest from app.js
  • Scan code for TODOs and comments
  • Fix themes being gross in some browsers
  • Finish light theme
• Get 'new' working again (as in =new Object)
• When creating name, check for valid symbols and existing names
• Make sure edit without replacement works on strings, dates etc
• Add back array and object literal support? If so, stop extra brackets being added when add new key to object literal?

• Undo/redo
• RO table support
• IO and sharing (use Monotreme?):
  • Share sheets via url hash
  • Override cells via url querystring
  • WebDAV and remote servers
• Add highlighting behind occupied cells to show they're taken (eg if empty string or renders to eqivalent)
• Style regex differently
• Make a Mesh electron package
• Click on cells to reference in formula (or move cursor with arrow keys)
• Aggregations - SUM, AVERAGE, etc. Predefine these functions? Have the UI insert them automatically?
• Make it easier to manage dates
• Why lookup tables are awesome (incl use of 'find')
• Copy and paste data in/out
• Guide on setting up a WebDAV server
• Move around cell locations via dragging mouse
• Split reducer table so that each 'state component' has its own column (separate fns?), eg formula bar, cells, etc
• Edit table header to rename

Miscellaneous

• Empty string entry
• Change add row/col labels so take up less height/width?
• Figure out how to manage row/col widths
• Add row/column indices (useful for counting / IDing). Similarly, way to see the coords of the selected cell?
• Excel -> JS function equivalent table
• APL/K support
• Version that supports TypeScript or all the latest JS features (bigints, realms, etc)
• Figure out how to manage Recast being pasted into the spreadsheet app (how to speed up parsing on change?)
• What to display for cells that have an invisible string? What about objects that have no string rep (eg Array.prototype)?
• Center function symbol in cell?
• Overflow - make expand to literal size?
• Boolean cells - hardcode vs softcode (take into account colour vs background)
• Should there be a function that lets you specify which cells you want the values of? IE don't get it all, all the time (feels wasteful)
• APLers don't use libraries