mdn / webassembly-examples

Code examples that accompany the MDN WebAssembly documentation — see https://developer.mozilla.org/en-US/docs/WebAssembly.

webassembly-examples

Code examples that accompany the MDN WebAssembly documentation — see https://developer.mozilla.org/en-US/docs/WebAssembly.

Testing/modifying the examples

The examples can be tested locally by running a local server to serve your directory of choice.

If you modify any .wat files for testing you will need to generate a corresponding .wasm file, replacing the existing version in the folder. This can be done using the wat2wasm tool, which is part of the WABT: The WebAssembly Binary Toolkit (for setup/usage see Converting the text .wat into a binary .wasm file on MDN and the readme in the WABT GitHub repo.

Note that some examples use features that are still considered optional. These are listed in the supported proposals section on the WABT README.md, along with the flags used to invoke them. For example, to build WASM for the multi-memory example you will need to specify the --enable-multi-memory flag as shown:

wat2wasm --enable-multi-memory multi-memory.wat

webassembly-examples's Issues

Memory example doesn't show how to pass memory as an import

https://github.com/mdn/webassembly-examples/blob/master/js-api-examples/memory.html#L13

So you've created a Memory instance. How can I send it as an import for instantiation?

Provide source code that you used for demos

There are cool examples inside understanding-text-format folder.
And compiled wasm files. But what the source for them? Is it C code or C++. How does it look like. Because without it, demos are useless.

online examples feature wanted

online examples feature wanted

https://mdn.github.io/webassembly-examples/js-api-examples

https://mdn.github.io/webassembly-examples/js-api-examples/table.html

CODE_OF_CONDUCT.md file missing

As of January 1 2019, Mozilla requires that all GitHub projects include this CODE_OF_CONDUCT.md file in the project root. The file has two parts:

1. Required Text - All text under the headings Community Participation Guidelines and How to Report, are required, and should not be altered.
2. Optional Text - The Project Specific Etiquette heading provides a space to speak more specifically about ways people can work effectively and inclusively together. Some examples of those can be found on the Firefox Debugger project, and Common Voice. (The optional part is commented out in the raw template file, and will not be visible until you modify and uncomment that part.)

If you have any questions about this file, or Code of Conduct policies and procedures, please see Mozilla-GitHub-Standards or email [email protected].

(Message COC001)

Error when compiling wasm-table.wat

wasm-table.wat:11:20: error: unexpected token $return_i32, expected ).
(call_indirect $return_i32)

ost

chore: repository standard

Following the guidelines defined in mdn/mdn#168

All repositories should have the following settings:

#31 (comment)

#31 (comment)

#31 (comment)

#31 (comment)

#31 (comment)

#31 (comment)

How dose "WebAssembly.Memory" work?

I see that you add the code below in js-api-example/memory.html, but the variable "memory" not been used in anywhere.

var memory = new WebAssembly.Memory({initial:10, maximum:100});

Thanks.

please add c/c++ source code of webassembly-examples/js-api-examples/table2.wat

actually, I don't how to use 'import' before compiled . thanks!

Add C/C++/Rust examples to go with the wat files

I'm not sure if this is the right place for this, but it would definitely help a lot in understanding how these parts fit if we had a C/C++/Rust (at least one) version of the examples.

TypeError: Incorrect response MIME type. Expected 'application/wasm'

Since application/wasm isn't an official MIME type yet, WebAssembly/spec#573, in case you got the type error of an incorrect response MIME type, you can add the following line in file /etc/mime.types and then restart the server.

application/wasm    wasm

FYI:
https://bugs.python.org/issue31670
python/cpython#3861

Nk

#<Module> could not be cloned

When I try to execute scripts at this demo page I see the next errors:

Uncaught (in promise) DOMException: Failed to execute 'postMessage' on 'Worker': #<Module> could not be cloned.
    at fetch.then.then.then.mod (https://mdn.github.io/webassembly-examples/js-api-examples/index-compile.html:19:16)
    at <anonymous>
fetch.then.then.then.mod @ index-compile.html:19
Promise resolved (async)
(anonymous) @ index-compile.html:18

My browser is Chrome 62.0.3202.89

Which format is relevant?

When I check the examples, the simple add function looks like below:

(module
  (func $add (param $lhs i32) (param $rhs i32) (result i32)
    get_local $lhs
    get_local $rhs
    i32.add)
  (export "add" (func $add))
)

But other examples use the format below:

(module
  (func $add (param $lhs i32) (param $rhs i32) (result i32)
    (i32.add
      (get_local $lhs)
      (get_local $rhs))
  (export "add" (func $add))
)

For instance: https://cdn.rawgit.com/WebAssembly/sexpr-wasm-prototype/2bb13aa785be9908b95d0e2e09950b39a26004fa/demo/index.html

use local.get instead of get_local

The MDN documentation uses local.get/local.set instead of get_local/set_local.

I think the sample code should be updated.

https://developer.mozilla.org/en-US/docs/WebAssembly/Understanding_the_text_format

local:

- get_local
+ local.get
- set_local
+ local.set

global:

- get_global
+ global.get
- set_global
+ global.set