├── .github
    └── workflows
    │   └── build.yml
├── LICENSE
├── README.md
└── frontend
    ├── index.html
    └── index.js


/.github/workflows/build.yml:
--------------------------------------------------------------------------------
 1 | name: build
 2 | 
 3 | on:
 4 |   merge_group:
 5 |   pull_request:
 6 |   push:
 7 |     branches:
 8 |       - master
 9 |   workflow_dispatch:
10 | 
11 | jobs:
12 |   build:
13 |     name: build
14 |     runs-on: ubuntu-latest
15 |     permissions:
16 |       pages: write
17 |       id-token: write
18 |     steps:
19 | 
20 |       - name: setup-alex-happy
21 |         run: |
22 |           pushd "$(mktemp -d)"
23 |           cabal path --installdir >> "$GITHUB_PATH"
24 |           cabal update
25 |           cabal install \
26 |             alex \
27 |             happy
28 |           popd
29 | 
30 |       - name: setup-ghc-wasm
31 |         run: |
32 |           pushd "$(mktemp -d)"
33 |           curl -f -L --retry 5 https://gitlab.haskell.org/haskell-wasm/ghc-wasm-meta/-/archive/master/ghc-wasm-meta-master.tar.gz | tar xz --strip-components=1
34 |           FLAVOUR=9.12 ./setup.sh
35 |           ~/.ghc-wasm/add_to_github_path.sh
36 |           popd
37 | 
38 |       - name: checkout
39 |         uses: actions/checkout@v4
40 | 
41 |       - name: checkout
42 |         uses: actions/checkout@v4
43 |         with:
44 |           repository: haskell-wasm/pandoc
45 |           ref: wasm
46 |           path: pandoc
47 | 
48 |       - name: gen-plan-json
49 |         run: |
50 |           pushd pandoc
51 |           wasm32-wasi-cabal build pandoc-cli --dry-run
52 |           popd
53 | 
54 |       - name: wasm-cabal-cache
55 |         uses: actions/cache@v4
56 |         with:
57 |           key: wasm-cabal-cache-${{ hashFiles('pandoc/dist-newstyle/cache/plan.json') }}
58 |           restore-keys: wasm-cabal-cache-
59 |           path: |
60 |             ~/.ghc-wasm/.cabal/store
61 |             pandoc/dist-newstyle
62 | 
63 |       - name: build
64 |         run: |
65 |           pushd pandoc
66 |           wasm32-wasi-cabal build pandoc-cli
67 |           popd
68 | 
69 |       - name: dist
70 |         run: |
71 |           mkdir dist
72 |           wasm-opt --low-memory-unused --converge --gufa --flatten --rereloop -Oz $(find pandoc -type f -name pandoc.wasm) -o dist/pandoc.wasm
73 |           cp frontend/*.html frontend/*.js dist
74 | 
75 |       - name: test
76 |         run: |
77 |           wasmtime run --dir $PWD::/ -- dist/pandoc.wasm pandoc/README.md -o pandoc/README.rst
78 |           head --lines=20 pandoc/README.rst
79 | 
80 |       - name: upload-pages-artifact
81 |         uses: actions/upload-pages-artifact@v3
82 |         with:
83 |           path: dist
84 |           retention-days: 90
85 | 
86 |       - name: deploy-pages
87 |         uses: actions/deploy-pages@v4
88 | 


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
 1 | MIT License
 2 | 
 3 | Copyright (c) Tweag I/O Limited.
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # `pandoc-wasm`
 2 | 
 3 | [![Chat on Matrix](https://matrix.to/img/matrix-badge.svg)](https://matrix.to/#/#haskell-wasm:matrix.terrorjack.com)
 4 | 
 5 | The latest version of `pandoc` CLI compiled as a standalone
 6 | `wasm32-wasi` module that can be run by engines like `wasmtime` as
 7 | well as browsers.
 8 | 
 9 | ## [Live demo](https://tweag.github.io/pandoc-wasm)
10 | 
11 | Stdin on the left, stdout on the right, command line arguments at the
12 | bottom. No convert button, output is produced dynamically as input
13 | changes.
14 | 
15 | You're also more than welcome to fetch the
16 | [`pandoc.wasm`](https://tweag.github.io/pandoc-wasm/pandoc.wasm)
17 | module and make your own customized app. `pandoc.wasm` is fully
18 | `wasm32-wasi` compliant and doesn't make use of any JSFFI feature in
19 | the ghc wasm backend.
20 | 
21 | ## Building
22 | 
23 | `pandoc.wasm` is built with 9.12 flavour of ghc wasm backend in CI,
24 | which can be installed via
25 | [`ghc-wasm-meta`](https://gitlab.haskell.org/haskell-wasm/ghc-wasm-meta). You
26 | need at least 9.10 since it's the earliest major version with (my
27 | non-official) backports for ghc wasm backend's Template Haskell & ghci
28 | support.
29 | 
30 | It's built using my
31 | [fork](https://github.com/haskell-wasm/pandoc/tree/wasm) which is
32 | based on latest `pandoc` release and patches dependencies, cabal
33 | config as well as some module code to make things compilable to wasm:
34 | 
35 | - No http client/server functionality. `wasip1` doesn't have proper
36 |   sockets support anyway, and support for future versions of wasi is
37 |   not on my radar for now.
38 | - No lua support. lua requires `setjmp`/`longjmp` which already work
39 |   in `wasi-libc` to some extent, but that requires wasm exception
40 |   handling feature which is not supported by `wasmtime` yet.
41 | 
42 | Other functionalities should just work, if not feel free to file a bug
43 | report :)
44 | 
45 | ## Acknowledgements
46 | 
47 | Thanks to John MacFarlane and all the contributors who made `pandoc`
48 | possible: a fantastic tool that has benefited many developers and is a
49 | source of pride for the Haskell community!
50 | 
51 | Thanks to all past efforts of using `asterius` to compile `pandoc` to
52 | wasm, including but not limited to:
53 | 
54 | - George Stagg's [`pandoc-wasm`](https://github.com/georgestagg/pandoc-wasm)
55 | - Yuto Takahashi's [`wasm-pandoc`](https://github.com/y-taka-23/wasm-pandoc)
56 | - My legacy asterius pandoc [demo](https://asterius.netlify.app/demo/pandoc/pandoc.html)
57 | 


--------------------------------------------------------------------------------
/frontend/index.html:
--------------------------------------------------------------------------------
 1 | <!DOCTYPE html>
 2 | <html lang="en">
 3 |   <head>
 4 |     <meta charset="UTF-8" />
 5 |     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
 6 |     <title>pandoc-wasm playground</title>
 7 |     <style>
 8 |       body {
 9 |         display: flex;
10 |         flex-direction: column;
11 |         height: 100vh;
12 |         margin: 0;
13 |         font-family: monospace;
14 |       }
15 | 
16 |       #container {
17 |         display: flex;
18 |         flex: 1;
19 |         overflow: hidden;
20 |       }
21 | 
22 |       textarea {
23 |         width: 50%;
24 |         height: 100%;
25 |         border: none;
26 |         padding: 1rem;
27 |         resize: none;
28 |         box-sizing: border-box;
29 |         font-size: 1rem;
30 |         font-family: monospace;
31 |       }
32 | 
33 |       #input {
34 |         border-right: 1px solid #ccc;
35 |       }
36 | 
37 |       #output {
38 |         background-color: #f5f5f5;
39 |         color: #333;
40 |       }
41 | 
42 |       #arguments-container {
43 |         padding: 0.5rem;
44 |         border-top: 1px solid #ccc;
45 |         background-color: #f9f9f9;
46 |       }
47 | 
48 |       #arguments {
49 |         width: calc(100% - 1rem);
50 |         padding: 0.5rem;
51 |         font-size: 1rem;
52 |         box-sizing: border-box;
53 |         font-family: monospace;
54 |       }
55 |     </style>
56 |   </head>
57 |   <body>
58 |     <div id="container">
59 |       <textarea
60 |         id="input"
61 |         readonly
62 |         placeholder="Loading wasm module..."
63 |       ></textarea>
64 |       <textarea
65 |         id="output"
66 |         readonly
67 |         placeholder="Output will be displayed here..."
68 |       ></textarea>
69 |     </div>
70 |     <div id="arguments-container">
71 |       <input type="text" id="arguments" value="-f markdown -t rst" />
72 |     </div>
73 |     <script type="module">
74 |       import { pandoc } from "./index.js";
75 | 
76 |       document.getElementById("input").readOnly = false;
77 |       document.getElementById("input").placeholder = "Enter your input here...";
78 | 
79 |       async function updateOutput() {
80 |         const inputText = document.getElementById("input").value;
81 |         const argumentsText = document.getElementById("arguments").value;
82 |         try {
83 |           const output = pandoc(argumentsText, inputText);
84 |           document.getElementById("output").value = output;
85 |         } catch (err) {
86 |           document.getElementById("output").value = `Error: ${err.message}`;
87 |         }
88 |       }
89 | 
90 |       document.getElementById("input").addEventListener("input", updateOutput);
91 |       document
92 |         .getElementById("arguments")
93 |         .addEventListener("input", updateOutput);
94 |     </script>
95 |   </body>
96 | </html>
97 | 


--------------------------------------------------------------------------------
/frontend/index.js:
--------------------------------------------------------------------------------
 1 | import {
 2 |   WASI,
 3 |   OpenFile,
 4 |   File,
 5 |   ConsoleStdout,
 6 |   PreopenDirectory,
 7 | } from "https://cdn.jsdelivr.net/npm/@bjorn3/browser_wasi_shim@0.3.0/dist/index.js";
 8 | 
 9 | const args = ["pandoc.wasm", "+RTS", "-H64m", "-RTS"];
10 | const env = [];
11 | const in_file = new File(new Uint8Array(), { readonly: true });
12 | const out_file = new File(new Uint8Array(), { readonly: false });
13 | const fds = [
14 |   new OpenFile(new File(new Uint8Array(), { readonly: true })),
15 |   ConsoleStdout.lineBuffered((msg) => console.log(`[WASI stdout] ${msg}`)),
16 |   ConsoleStdout.lineBuffered((msg) => console.warn(`[WASI stderr] ${msg}`)),
17 |   new PreopenDirectory("/", [
18 |     ["in", in_file],
19 |     ["out", out_file],
20 |   ]),
21 | ];
22 | const options = { debug: false };
23 | const wasi = new WASI(args, env, fds, options);
24 | const { instance } = await WebAssembly.instantiateStreaming(
25 |   fetch("./pandoc.wasm"),
26 |   {
27 |     wasi_snapshot_preview1: wasi.wasiImport,
28 |   }
29 | );
30 | 
31 | wasi.initialize(instance);
32 | instance.exports.__wasm_call_ctors();
33 | 
34 | function memory_data_view() {
35 |   return new DataView(instance.exports.memory.buffer);
36 | }
37 | 
38 | const argc_ptr = instance.exports.malloc(4);
39 | memory_data_view().setUint32(argc_ptr, args.length, true);
40 | const argv = instance.exports.malloc(4 * (args.length + 1));
41 | for (let i = 0; i < args.length; ++i) {
42 |   const arg = instance.exports.malloc(args[i].length + 1);
43 |   new TextEncoder().encodeInto(
44 |     args[i],
45 |     new Uint8Array(instance.exports.memory.buffer, arg, args[i].length)
46 |   );
47 |   memory_data_view().setUint8(arg + args[i].length, 0);
48 |   memory_data_view().setUint32(argv + 4 * i, arg, true);
49 | }
50 | memory_data_view().setUint32(argv + 4 * args.length, 0, true);
51 | const argv_ptr = instance.exports.malloc(4);
52 | memory_data_view().setUint32(argv_ptr, argv, true);
53 | 
54 | instance.exports.hs_init_with_rtsopts(argc_ptr, argv_ptr);
55 | 
56 | export function pandoc(args_str, in_str) {
57 |   const args_ptr = instance.exports.malloc(args_str.length);
58 |   new TextEncoder().encodeInto(
59 |     args_str,
60 |     new Uint8Array(instance.exports.memory.buffer, args_ptr, args_str.length)
61 |   );
62 |   in_file.data = new TextEncoder().encode(in_str);
63 |   instance.exports.wasm_main(args_ptr, args_str.length);
64 |   return new TextDecoder("utf-8", { fatal: true }).decode(out_file.data);
65 | }
66 | 


--------------------------------------------------------------------------------