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8.8 KiB
8.8 KiB
[Using](using.html) -
[Building](building.html) -
[🦋](perl6.html) -
Notes -
[Legal](legal.html) -
[Wiki](https://github.com/haukex/webperl/wiki) \]
Misc. Notes on WebPerl
======================
Links
-----
Other places I've written about WebPerl:
- [Run Perl 5 in the Browser!](https://www.perlmonks.org/?node_id=1220426)
- [WebPerl Regex Tester (beta)](https://www.perlmonks.org/?node_id=1221705)
- [Embedding WebPerl Code Demos into Other Pages](https://www.perlmonks.org/?node_id=1223812)
- [WebPerl now has Experimental Perl 6 Support!](https://www.perlmonks.org/?node_id=1225647)
Talks:
- YAPC::EU 2018 in Glasgow - [lightning talk](http://act.perlconference.org/tpc-2018-glasgow/talk/7475), [Video Link](https://youtu.be/KrGSg7uVZj0?t=29520)
- *(planned)* German Perl Workshop 2019 - [talk](http://act.yapc.eu/gpw2019/talk/7616) (in German 🇩🇪)
- *(hopefully)* YAPC::EU 2019 ([PerlCon](https://perlcon.eu/)) in Rīga
[](https://doi.org/10.5281/zenodo.1400490)
### "In the Press"
- WebPerl gets a mention in Will Braswell's talk ["Perl 11 - The Future of Saint Larry's Language"](https://fosdem.org/2019/schedule/event/perl11/)
- [Perl Advent Calendar 2018, Day 2](http://www.perladvent.org/2018/2018-12-02.html) (by Mark Fowler)
- [Reddit: Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should (2018-10-22)](https://www.reddit.com/r/programmingcirclejerk/comments/9qerw5/your_scientists_were_so_preoccupied_with_whether/) 😉
- [Hacker News (2018-10-21)](https://news.ycombinator.com/item?id=18269071)
- [Reddit /r/programming (2018-10-21)](https://www.reddit.com/r/programming/comments/9q65tf/run_perl_in_the_browser_with_webperl/)
- [Facebook Group "Perl Programmers" (2018-10-20)](https://www.facebook.com/groups/perlprogrammers/permalink/2141844605848316/)
- [Reddit /r/perl: WebPerl Regex Tester (2018-09-05)](https://www.reddit.com/r/perl/comments/9d5n77/webperl_regex_tester/)
TODOs
-----
1. Testing
- How to best disable individual tests that we know won't work? (qx etc.)
- How to handle the many tests that call an external Perl?
- patching t/test.pl's runperl() seems easiest at the moment, and we can use the iframe method from the IDE
- Continue work on `WebPerl.t`
- More tests for Unicode support (Perl/JS interface, Perl.eval(), plus Emscripten's virtual FS)
- Focus on getting the tests running in the browser instead of node.js
- How to best package tests?
- If possible, a separate bundle, so that it can be loaded optionally and we don't need to rebuild
- How does `make test` find and handle all the various modules' `t`s?
2. Misc
- Write up a full RPC example
- Add `Future` to the WebPerl build for a little more async niceness?
- Would `Future::AsyncAwait` work in WebPerl? (Or maybe with a JS backend?)
- `Future::HTTP` (probably just as a frontend to XHR?)
- Improve Perl 6 integration
- Build a packaged Rakudo.js ourselves instead of borrowing from <https://perl6.github.io/6pad/>
- Perhaps get an API change or two into Rakudo.js: `STDOUT` currently gets output with HTML escapes
- See also notes in [Perl 6 Support 🦋](perl6.html)
- Investigate Emscripten's main loop concept for handling nonblocking sockets?
- Turn some patches from emperl5 into patches for P5P
- Submit some patches to Emscripten
- <https://github.com/kripken/emscripten/pull/7005>
- <https://github.com/kripken/emscripten/issues/7029>
- Would we need to patch Perl's signal functions if Emscripten's stubs weren't noisy?
- Add `Perl.Util` functions for making file uploads and downloads easier
- Plus an example showing how to use it to run a "legacy" Perl script with inputs and output
- There is some potential for restructuring:
- `Perl.glue()` and `Perl.dispatch()` could go into `WebPerl.xs` (?)
- Parts of `webperl.js` could go into `common_preamble.js` or `WebPerl.xs`,
so that `emperl.js` is runnable on its own in a Web Worker (?)
(see notes in `perlrunner.html` / `e12f1aa25a000`)
- `nodeperl_dev_prerun.js` could probably be merged into that as well
- Could put a `WebPerl` stub on CPAN
- In theory could write a `WebPerl::Local` that contains the `WebPerl` API, and
have various drivers such as `WebPerl::WebDriver` or `WebPerl::JSAny` that
runs the code given to WebPerl's `js()`...
- Regarding the funky syntax highlighting on GitHub: <https://github.com/atom/language-html/issues/88#issuecomment-431361414>
3. See Also
- <https://github.com/haukex/webperl/issues>
- <https://github.com/haukex/webperl/pulls>
- See also `TODO`s in the source tree by grepping for `TODO`
or using the included `findtodo.sh`.
SSL
---
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout selfsigned.key -out selfsigned.crt
...
Common Name (e.g. server FQDN or YOUR name) []: localhost
...
$ plackup --enable-ssl --ssl-key-file=selfsigned.key --ssl-cert-file=selfsigned.crt web/webperl.psgi
# then go to https://localhost:5000 and accept the certificate warning
Possible Improvements
---------------------
- More efficient JS/C/Perl glue
- Test/Support sockets/WebSockets
- for example, can we compile a DBD:: module to connect to a DB on the server?
- A RPC module for communicating between client and server Perls
- I think it's probably best to not have WebPerl prescribe a specific RPC mechanism,
since there's a big variety and many are pretty simple to implement using e.g. jQuery
- Support some of the Emscripten C API (like wget?)
- Try to shrink the download size more (exclude more modules, ...?)
Limitations
-----------
- Only works in browsers with WebAssembly support
(asm.js requires aligned memory access, and Perl apparently has quite a few places with unaligned access)
- 32-bit ints
- No `system`, `qx`, `fork`, `kill`, `wait`, `waitpid`, threads, etc.
- Theoretically, we could link in BusyBox to get a shell and utilities (??)
- (`system` and `qx` support could theoretically be added by patching `pp_system`/`pp_backtick` in `pp_sys.c`)
- No signals (except `SIGALRM`)
- In the current configuration, `exit` is not supported, and therefore `atexit` handlers aren't supported
(see discussion in [Using WebPerl](using.html), and `NO_EXIT_RUNTIME` in the Emscripten documentation -
currently it seems to make the most sense to build with `NO_EXIT_RUNTIME=1`)
- Static linking, requires rebuild to add modules
(Emscripten apparently only supports asm.js dynamic linking when dynamic memory growth is disabled, which is not very useful)
Release Checklist
-----------------
- Update `Changes.md` with all changes since last release
As an example, to list changes since a specific version, excluding the regex tester:
$ git log --stat v0.05-beta.. -- . ':!web/regex_tester.html' ':!.gitignore'
- Also make sure that the documentation in `using.md` etc. mentions when features were added/deprecated
- Update version numbers everywhere; use `grep` to find them, for example:
$ grep -Er --exclude-dir=work --exclude-dir=.git --exclude-dir=emperl5 --exclude=emperl.* '0\.0[0-9]' .
$ ( cd emperl5; grep -Er '0\.0[0-9]' `git diff --numstat --diff-filter=A v5.28.0 HEAD | cut -f3` )
At a minimum there is:
- `web/webperl.js` - `Perl.WebPerlVersion`
- `emperl5/ext/WebPerl/lib/WebPerl.pm` - `$VERSION`
- `pages/index.md` and `pages/using.md` - download links
- Update [Subresource Integrity](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) values as needed, e.g.:
$ perl -wMstrict -MDigest::SRI=sri -le 'print sri "SHA-256","web/webperl.js"'
- Build and create dist, e.g. `build/build.pl --reconfig --dist=webperl_prebuilt_v0.07-beta`
- Test all build results, both from `file://...` and `http://localhost`
- Add tags, the `webperl` repo gets an annotated tag such as `v0.07-beta`,
and the `emperl5` repo gets an unannotated tag such as `webperl_v0.07-beta`,
then `git push --tags`
- Create a release on GitHub and upload the `webperl_prebuilt_*.zip` as an asset
- Uploading to AWS S3:
1. Run `gzip -9` on `emperl.*` and `webperl.js`
2. Rename them to remove the `.gz` ending
3. Upload them with the appropriate `Content-Type` (see e.g. `web/webperl.psgi`) and a `Content-Encoding` of `gzip`
- If there was a `pages_for_vX.XX` branch of `gh-pages`, don't forget to merge that
Prior Art
---------
Several people have built microperl with Emscripten:
- Harsha <https://github.com/moodyharsh/plu>
- Shlomi Fish <https://github.com/shlomif/perl5-for-JavaScript--take2>
- FUJI Goro <https://github.com/gfx/perl.js>
***
Copyright (c) 2018 Hauke Daempfling (haukex@zero-g.net)
at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB),
Berlin, Germany, <http://www.igb-berlin.de>
Please see the ["Legal" page](legal.html) for details.
***
You can find the source for this page at
<https://github.com/haukex/webperl/blob/gh-pages/notes.md>