Hints for using Embperl 2.x
---------------------------

Embperl 2 contains nearly 7000 lines new (mostly C-) code. Also I
have done a lot of testing, don't expect it to work without errors!

Please report any weired behaviour to the embperl mailing list, but
be sure to read this whole README to understand what can't work so far.

The Embperl core now works in a totaly different way. It is devided into
smaller steps:

    1 reading the source
    2 parseing 
    3 compiling 
    4 executing
    5 outputing

Further version will allow to replace every single step of this pipeline
with custom modules. Also it will be possible to cascade multiple
processors. This allows for example to have Embperl and SSI in one file
and to parse the file only once, feeding it first to the SSI processor and
afterwards to the Embperl processor. Also the parser will be exchangeable
in future version to allow for example to use an XML parser and an
XSLT stylesheet processor.

These new execution scheme is also faster, because html tags and metacommands
are parsed only once (Perl code was also (and is still) cached in 1.x)
My first benchmarks show 25%-50% faster execution under mod_perl for pages
longer then 20K (For short pages ( < 5K ouput) you won't see a great difference)

Another new feature is that the syntax of the Embperl parser is defined
with in the module HTML::Embperl::Syntax and can be modified as nessecary.
See the file Embperl/Syntax.pm how it looks like and 

perldoc HTML::Embperl::Syntax

for a short description. A further verion will add an API to this syntax module,
so custom syntaxes can be easily added, without modifiy Syntax.pm itself.

Also left for one of the next release is the caching of (parts of) the output.


The following difference to Embperl 1.x apply:
------------------------------------------------------

- The following options can currently only set from the httpd.conf:
     optRawInput, optKeepSpaces

- The following options are currently not supported:
     optDisableHtmlScan, optDisableTableScan,
     optDisableInputScan, optDisableMetaScan

- Nesting must be properly. I.e. you cannot put a <table> tag (for an
  dynamic table) inside an if and the </table> inside another if.
  (That still works for static tables)

- optUndefToEmptyValue is always set and cannot be disabled.

- [$ foreach $x (@x) $] requires now the bracket around the
  array (like Perl)


The following things are not fully tested/working yet:
------------------------------------------------------

- [$ sub $] ... [$ endsub $]

- [- exit -]

- [- print OUT "foo" -]

- safe namespaces


Embperl 1.x compatibility flag
------------------------------

If you don't have a separate computer to make the test setup, you can
include

PerlSetEnv EMBPERL_EP1COMPAT 1

at the top level of your httpd.conf, then Embperl will behave just the same
like Embperl 1.3b3. In the directories where you make your tests, you
inlcude a

PerlSetEnv EMBPERL_EP1COMPAT 0

to enable the new engine.

but _DON'T_ use this one a production machine. While this compatibility mode
is tested and shows no problems for me, it's not so hard tested as 1.3b3
itself!