JE, version 0.042

JE is a pure-Perl ECMAScript (JavaScript) engine. Here are some of its advantages:

• Easy to install (no C compiler necessary)
• Compatible with Data::Dump::Streamer, so the runtime environment can be serialised
• The parser can be extended/customised to support extra (or fewer) language features (not yet complete)
• All JavaScript datatypes can be manipulated directly from Perl (they all have overloaded operators)

Here are its main weakness:

• It's slow (well, what did you expect?).
• It uses lots of memory.
• It leaks memory (to be fixed).

This is still an alpha release. The core objects are not yet complete, but as long as you don't need all the methods of dates (more precisely, those beginning with â€^~setâ€^TM), this module is actually usable.

If you have the time and the interest, please experiment with this module (or maybe even lend a hand :-). If you have any ideas as to how the API could be improved or reworked, please e-mail me.

CHANGES IN THIS RELEASE

New feature: We extend ECMAScript by treating hyphens in regexp character classes that are adjacent to \d, \s or \w always as literal hyphens and no longer as syntax errors (RT #51123). Bug fixes:
• JE::Numberâ€^TMs id method has been fixed such that === and isNan now recognise positive NaN as NaN on Windows (RT #51036). • Parsing long strings no longer causes perl 5.8 to crash on Windows (see http://www.nntp.perl.org/group/perl.cpan.testers/2009/11 /msg5881496.html). I fixed this by reÃ&hibar;ncorporating part of Kevin Cameronâ€^TMs code (RT #49607) that I had simplified to make it faster.

TO DO

• Make the parser extensible/customisable
• Finish the core object classes (Date needs to be finished)
• Add more helpful error messages
• Determine some logical way of dealing with locale settings (for String.prototype.localeCompare, et al.)
• Finish writing tests
• Deal with circular references
• Finish making built-in JS properties load lazily
• Finish optimising JS compiled code by turning it into Perl code
• Other optimisations

INSTALLATION

The easiest way to install this module is to use the CPAN module or the cpan script:

[sudo] perl -MCPAN -e "install JE"

[sudo] cpan
cpan> install JE

Or you can use the following:

perl Makefile.PL
make
make test
[sudo] make install

PREREQUISITES

This module requires perl 5.8.3 or higher and the following modules: • Scalar::Util version 1.14 or later
• The TimeDate distribution (more precisely, Time::Zone, Date::Format and Date::Parse)
• Encode 2.08 or later

For perl versions earlier than 5.9.4 it also requires Tie::RefHash::Weak.

Later it will probably require Unicode::Collate.

There is a slight incompatibility with perl version 5.8.3. If you try to create a regular expression with invalid modifiers, you will get a warning as well as a SyntaxError. This causes one of the test scripts (parse08-regexps.t) to fail.

DOCUMENTATION

After installing, you can find documentation for this module with the perldoc command.

perldoc JE

Or try using man (it's faster, in my experience):

man JE

ACKNOWLEDGEMENTS

Thanks to Kevin Cameron [ kevin cameron com ] for his contributions,

to Max Maischein [ webmaster corion net ] for letting me use his tests,

to Andy Armstrong    [ andy        hexten net       ],
   Yair Lenga        [ yair lenga  gmail com        ],
   Alex Robinson     [ alex        solidgoldpig com ],
   Christian Forster [ boronk      boronk de        ] and
   Imre Rad          [ radimre     freemail hu      ]

for their suggestions,

and to the CPAN Testers for their helpful reports.

COPYRIGHT AND LICENCE

Copyright (C) 2007-9 Father Chrysostomos

This program is free software; you may redistribute it and/or modify it under the same terms as perl.