Use Zig in CoCalc

Same content on GitHub: https://github.com/williamstein/zig-cocalc-primes

CoCalc now supports the programming language zig. (Use the Experimental software environment as of Aug 12, 2021, but this will be default in a few days.)

• You can edit files that end in .zig and get syntax highlighting (from C) and formatting (by ctrl+shift+f) using zig fmt.
• The zig command line program is pre-installed.
• You can also click +New --> VS Code server, and run Visual Studio Code Server in another tab.
  • Install the zig extension from the extension marketplace (which takes about 5 seconds), then
  • Referesh your VS Code browser tab.

Example: counting primes with a sieve

I created two examples of zig programs for counting primes, starting from this.

1. zig-static - uses static memory on the stack to compute $\pi(n)$ for some values of $n$. Native only works in debug mode (the default); crashes when built with -O ReleaseFast . WASM works in ReleaseFast mode.
2. zig-dynamic - uses dynamically allocated memory to compute $\pi(n)$ for some values of $n$.

In each case we include comments about how to compile and run these natively locally, and also using web assembly.

Timings are roughly:

• sieve: native in debug mode: 0.16s; wasm in debug mode: 0.17s; wasm in ReleaseFast mode: 0.09s;
• sieve2 in ReleaseFast mode: 0.05s; wasm 0.06s.

For comparison, I've also included the dynamically allocated computation in C, Javascript and Python, where timings are as follows. You can find those in the corresponding subdirectories.

• C - 0.05s.
• Javascript - 0.13s
• Python - 2s