power assert and perl.js

Power AssertYAPC::ASIA 2013, 9/20, Kanagawa

Fuji Goro (gfx) <[email protected]>

13年9月20日金曜日

mailto:[email protected]

mailto:[email protected]

perl.js Fuji Goro (gfx) YAPC::Asia 2013

myself

Working at COOKPAD, Inc.

Rubyist / Androider / JSXer

CPAN:

Xslate

Mouse

Plack::Middleware::DevFavicon



Power Assert

http://dontmindthelanguage.wordpress.com/2009/12/11/groovy-1-7-power-assert/

Invented in Groovy

Ported to JavaScript by @t_wata, 2013

Ported to Perl by @tokurhiom, 2013







Test::Power

expect { $x->is_foo }

expect { $x->foo eq ‘bar’ }



FAILURE MESSAGES

not ok 1 - L7 : expect { $h->foo->bar == 42 };

# $h->foo

# => undef

# $h

# => bless( {}, 'main' )



END

Part 1. End.



Part 2.

perl.js - Perl 5.18.1 running on browsers

build with emscripten



Demo

http://gfx.github.io/perl.js/





Emscripten

LLVM to JavaScript compiler

Compile LLVM bitcode into JavaScript



Emscripten

Use JavaScript as a machine code

Like a kernel & CPU, not an emulator nor translator

All the syscalls are implemented in the emscripten runtime libraries



For example: fork(2)

// src/library.jsfork: function() { // pid_t fork(void); // We don't support multiple processes. ___setErrNo(ERRNO_CODES.EAGAIN); return -1;},

Most POSIX syscalls are just dummies :(



utime(2)

// src/library_fs.jsutime: function(path, atime, mtime) { var lookup = FS.lookupPath(path, { follow: true }); var node = lookup.node; node.node_ops.setattr(node, { timestamp: Math.max(atime, mtime) });},

Emscripten has a virtual file system



BuilD PERL

Write own Makefile based on Makefile.micro

cf. pl! - Perl 5.16.3 based emscripten-ed perl



Problems

Does not support call main() more than twice

exit() closes stdin, stdout, stderr but there’s no way to open them again

Fatal errors which cause abort() breaks the internal state, which then needs to reload the page (the JavaScript interpreter)



Conclusion

Use emscripten for C/C++ applications

Write once, run everywhere



END

http://github.com/gfx/perl.js




power assert and perl.js

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