Coding raw WebAssembly Text - Dive into Wat

0:00 - Intro & Demos from Ben
1:06 - Hello in Wat
1:49 - Mini Wasm runner
2:36 - Fibonacci numbers in Zig
3:30 - Fibonacci numbers in Wat & Wasi
3:49 - Wasi
4:33 - Main loop, signedness
4:57 - Manual stack
5:28 - Calculating Fibonacci using Wasm stack
6:05 - Program run, more operand stack, binary size
7:04 - Print text and numbers using manual stack
8:04 - String constants
8:18 - Binary Wasm bytes
8:41 - Roland demo & Outro

[bensmith]

Thanks for the shout out!

WebAssembly is a funny format because it looks like a stack machine, but doesn’t have traditional dup/swap/rot operators, and the text format uses s-expressions but otherwise is not at all like a lisp!

In response to some other comments, WebAssembly is higher level than other machine code formats, primarily in the use of local variables instead of registers, and the requirement to use structured control-flow such as if and loop instead of jumps and branches. Neither of these are needed for safety, however, so it would have been possible to define it a different way.

By the way, there is a “folded” format for the if instruction. It is written like (if (condition) (then (expr)) (else (expr))).

Great video as always!

[tuffenduffen]

Having read the wasm spec, this video is very nice because the spec isn't very hands-on to put it lightly. Thank you very much!

[gamerzero]

Lol, didn't knew wasm text representation is lisp. That's kinda curious

[shilangyu]

Very nice showcase. Makes me seriously consider Wat as the target for my toy language. It seems legible enough to do easy debugging on it. It can also compile to standalone executables, which is always desirable.

[MyCodingDiary]

Your attention to detail and dedication to your craft is truly inspiring. Thank you for sharing your expertise with us!🖤❣

[andrewdunbar]

This was nice to see. I had a tiny bit of a play with WAT a year or so ago to see if it would bring back the nostalgia of doing machine code on the Z80 and assembly on the 68000.

I didn't play with AssemblyScript though, are you thinking of having a look at that?

[Rage]

2:40 — I take it you're using 0.10.1 Zig? Current way to iterate through integers is for(0..10) |n| {}

[enirya]

one thing that bugged me about WAT was that the rules for parentheses arent strict like lisp and it made writing it feel weirdly inconsistent

[alirezakarimi]

Please help me : This browser does not support WebAssembly.
This problem has occurred in some clients with Windows 11 and google chrome, whose browser is updated.

[stevenhe]

So, it is much higher-level than machine assembly languages, with strong inspiration from Lisp.