ePerl(3pm)						User Contributed Perl Documentation						ePerl(3pm)

NAME

       Parse::ePerl - Perl interface to the ePerl parser

SYNOPSIS

	 use Parse::ePerl;

	 $rc = Parse::ePerl::Preprocess($p);
	 $rc = Parse::ePerl::Translate($p);
	 $rc = Parse::ePerl::Precompile($p);
	 $rc = Parse::ePerl::Evaluate($p);
	 $rc = Parse::ePerl::Expand($p);

DESCRIPTION

       Parse::ePerl is the Perl 5 interface package to the functionality of the ePerl parser (see eperl(1) for more details about the stand-alone
       program). It directly uses the parser code from ePerl to translate a bristled script into a plain Perl script and additionally provides
       functions to precompile such scripts into P-code and evaluate those scripts to a buffer.

       All functions are parameterized via a hash reference $p which provide the necessary parameters. The result is a return code $rc which
       indicates success(1) or failure(0).

   PREPROCESSOR: $rc = Parse::ePerl::Preprocess($p)
       This is the ePerl preprocessor which expands "#include" directives.  See eperl(1) for more details.

       Possible parameters for $p:

       Script
	   Scalar holding the input script in source format.

       Result
	   Reference to scalar receiving the resulting script in bristled Perl format.

       BeginDelimiter
	   Scalar specifying the begin delimiter.  Default is ``"<:"''.

       EndDelimiter
	   Scalar specifying the end delimiter.  Default is ``":>"''.

       INC A reference to a list specifying include directories. Default is "@INC".

   TRANSLATION: $rc = Parse::ePerl::Translate($p)
       This is the actual ePerl parser, i.e. this function converts a bristled ePerl-style script (provided in "$p-"{Script}> as a scalar) to a
       plain Perl script. The resulting script is stored into a buffer provided via a scalar reference in "$p-"{Result}>. The translation is
       directly done by the original C function Bristled2Plain() from ePerl, so the resulting script is exactly the same as with the stand-alone
       program eperl.

       Possible parameters for $p:

       Script
	   Scalar holding the input script in bristled format.

       Result
	   Reference to scalar receiving the resulting script in plain Perl format.

       BeginDelimiter
	   Scalar specifying the begin delimiter.  Default is ``"<:"''.

       EndDelimiter
	   Scalar specifying the end delimiter.  Default is ``":>"''.

       CaseDelimiters
	   Boolean flag indicating if the delimiters are case-sensitive (1=default) or case-insensitive(0).

       Example: The following code

	 $script = <<'EOT';
	 foo
	 <: print "bar"; :>
	 quux
	 EOT

	 Parse::ePerl::Translate({
	     Script => $script,
	     Result => $script,
	 });

       translates the script in $script to the following plain Perl format:

	 print "foo
";
	 print "bar"; print "
";
	 print "quux
";

   COMPILATION: $rc = Parse::ePerl::Precompile($p);
       This is an optional step between translation and evaluation where the plain Perl script is compiled from ASCII representation to P-code
       (the internal Perl bytecode). This step is used in rare cases only, for instance from within Apache::ePerl(3) for caching purposes.

       Possible parameters for $p:

       Script
	   Scalar holding the input script in plain Perl format, usually the result from a previous Parse::ePerl::Translate(3) call.

       Result
	   Reference to scalar receiving the resulting code reference. This code can be later directly used via the &$var construct or given to
	   the Parse::ePerl::Evaluate(3) function.

       Error
	   Reference to scalar receiving possible error messages from the compilation (e.g.  syntax errors).

       Cwd Directory to switch to while precompiling the script.

       Name
	   Name of the script for informal references inside error messages.

       Example: The following code

	 Parse::ePerl::Precompile({
	     Script => $script,
	     Result => $script,
	 });

       translates the plain Perl code (see above) in $script to a code reference and stores the reference again in $script. The code later can be
       either directly used via &$script instead of "eval($script)" or passed to the Parse::ePerl::Evaluate(3) function.

   EVALUATION: $rc = Parse::ePerl::Evaluate($p);
       Beside Parse::ePerl::Translate(3) this is the second main function of this package. It is intended to evaluate the result of
       Parse::ePerl::Translate(3) in a ePerl-like environment, i.e. this function tries to emulate the runtime environment and behavior of the
       program eperl. This actually means that it changes the current working directory and evaluates the script while capturing data generated on
       STDOUT/STDERR.

       Possible parameters for $p:

       Script
	   Scalar (standard case) or reference to scalar (compiled case) holding the input script in plain Perl format or P-code, usually the
	   result from a previous Parse::ePerl::Translate(3) or Parse::ePerl::Precompile(3) call.

       Result
	   Reference to scalar receiving the resulting code reference.

       Error
	   Reference to scalar receiving possible error messages from the evaluation (e.g. runtime errors).

       ENV Hash containing the environment for %ENV which should be used while evaluating the script.

       Cwd Directory to switch to while evaluating the script.

       Name
	   Name of the script for informal references inside error messages.

       Example: The following code

	 $script = <<'EOT';
	 print "foo
";
	 print "bar"; print "
";
	 print "quux
";
	 EOT

	 Parse::ePerl::Evaluate({
	     Script => $script,
	     Result => $script,
	 });

       translates the script in $script to the following plain data:

	 foo
	 bar
	 quux

   ONE-STEP EXPANSION: $rc = Parse::ePerl::Expand($p);
       This function just combines, Parse::ePerl::Translate(3) and Parse::ePerl::Evaluate(3) into one step. The parameters in $p are the union of
       the possible parameters for both functions. This is intended as a high-level interface for Parse::ePerl.

AUTHOR

	Ralf S. Engelschall
	rse@engelschall.com
	www.engelschall.com

SEE ALSO

       eperl(1)

       Web-References:

	 Perl:	perl(1),  http://www.perl.com/
	 ePerl: eperl(1), http://www.engelschall.com/sw/eperl/

perl v5.14.2							    2012-04-07								ePerl(3pm)