p = new Perl('Sys::Hostname', 'Test::Harness')+In addition to creating an interpreter, this will also include the libraries +you pass to the Perl constructor, which is equivalent to use Sys::Hostname; +use Test::Harness. You can always include libraries explicitly by +using p.eval('use Sys::Hostname; use Test::Harness'). There is +also another way to do this: p.use('Sys::Hostname', 'Test::Harness'). +As you can see, TMTOWTDI. +
Note: If the statements above fail on you saying something about +libraries not found in the search path, you need to make sure the modules +PerlConnect uses, JS.pm and PerlConnect.pm live in some directory accessible +from the search path. Search path can be set by adjusting the value of PERLLIB +and PERL5LIB environment variables. See installation +for more details. +
Note: Despite the illusion p = new Perl(...) syntax might create, +there is actually only one version of the Perl interpreter running. I.e. +if you create two interpreters like this: +
p = new Perl; q = new Perl; ++Now you'll see that q["$a"] will give you $a's value +from p. +
p.eval("$a='ha-'x20");
Naturally, you will want to look at the result of your function calls +and eval statements. Suppose, you do something like this: +
line = p.eval("'-' x 80")+Perl's eval returns the last statement evaluated, unless you explicitly +say return. So now line contains 80 dashes. You can do +similar things with non-scalar data types: +
p.use('Time::gmtime'); ++assigns a Perl array to t. You can print t, use the for/in +syntax to walk through it, compute its length, etc. You can read and assign +to individual elements using the standard syntax. However, PerlValues, +that is, the value we get from Perl, don't support all the standard operations, +for instance, don't expect t.reverse() to work. Hashes can also +be returned from Perl: +
t = p.eval('Time::gmtime::gmtime') // returns +[49,0,4,24,6,98,5,204,0]
info=p.eval("{ver=>$], pid=>$$}")+Now you can look at individual hash keys like this: +
info["ver"] or info.pid+Suppose you want to use Perl to perform pattern-based string replacement. +Here's how you can do it from JavaScript: +
p.eval("\ ++and now +
sub perl_replace(){\ +
my($string, $find, $replace) += @_;\ +
eval(\"\\$string =~ +s/$find/$replace/g;\");\ +
return $string;\ +
}" +
);
p.perl_replace('Quick brown fox jumped over a lazy dog', +'dog', 'rhino')+produces what you'd expect. +
You can use the same syntax to call procedures defined in modules other +than main. The example with gmtime can be rewritten like +this: +
p.use('Time::gmtime'); ++ You can reference variables exported by modules other than main +like this: +
t = p.Time.gmtime.gmtime() // returns [49,0,4,24,6,98,5,204,0]
a=p.Foo.$bar or a=p.Foo["$bar"] or ++Each of the above statements return either an immediate JS value, for +scalar types, or a PerlValue for compound types. a.type contains +the type of the PerlValue in a. This may change because we +may end up separating Perl hashes and arrays into separate classes. +
a=p.Foo["@bar"]or a=p.Foo["%bar"]
use JS; ++and now you can do something like this: +
$js = new JS();
$js->eval(q/ ++Note: Please see test.js and test.pl, test scripts that test and +demonstrate various features of PerlConnect and JS.pm, respectively. They +will help get you started. +Object o = {}; ++/);
o.a = 'p'; +
o.b = 'q'; +
return o;
| Object | + +What it does | +
| Perl | + +Perl Interpreter Object. Its prototype type +is PerlModule, it corresponds to main::. Supports eval, +call, +use. | +
| PerlModule | + +Implements JS-like syntax for Perl modules. Doesn't +export provide any methods. path property shows the name of the +Perl module the object represents. | +
| PerlValue | + +Represents a value returned from eval, +call, +or obtained by using the subscript notation (p.Foo["@bar"]). Its +Perl type is stored in the type property. | +
See comments in the code, jsperl.c and JS.pm for more
+info.
+
Note: PerlConnect heavily relies on PerlConnect.pm, which
+does some background magic for it. PerlConnect.pm should not be
+used. Use JS.pm instead.
+
The following Perl packages (objects) are implemented:
+
+
| Package | + +What it contains | +
| JS | + +Doesn't do anything in particular at this +point except defining a constructor. So one can say $js = new +JS(), which will create a new runtime, add a context to it and return +that Context. JS also defines a bunch of private functions called from +C by PerlConnect. They are not exposed by default, but pushed onto @EXPORT_OK +array instead. | +
| JS::Runtime | + +Corresponds to JSRuntime* struct. Provides +a constructor and destructor. The destructor is invoked automatically, +so you don't have to worry about Runtime deallocation. Constructor syntax +is the following: $rt = new JS::Runtime(10_000), where +the parameter is the same number you pass to JS_NewRuntime. There +are many private functions created in JS.xs that are not exported +by default. | +
| JS::Context | + +Corresponds to JSContext* struct. Provides +a constructor and destructor. The destructor is invoked automatically, +so you don't have to worry about Context deallocation. Constructor syntax +is the following: $rt = new JS::Context($rt, 1_000), where +the parameter is the same number you pass to JS_NewContext. There +are many private functions created in JS.xs that are not exported +by default. | +
| JS::Object | + +Corresponds to JSObject* struct. There is not that much here +yet. This object is intended as a wrapper around the JSObject* struct. +Support for tying hashes and possibly arrays with JS::Objects +is coming. | +
| [JS::Array] | + +I am not quite sure if this is needed. One might probably get away +with just JS::Object defined. If it's implemented, it will be +very much similar to JS::Object above. | +
All the modules above follow the convention of storing the variable +they return in the $this variable of the current class. So $JS::Context::this +will always be the last context created. Currently, this is where JS +API function that require contexts get it. +
JS also builds a DLL, JS.dll which is supposed to reside where +Perl's DynaLoader can find it. On my machine I put it under c:\perl\lib\auto\JS\JS.dll. +You can also put it in c:\perl\lib\. You can probably adjust PERLLIB +to achieve the desired result. See Perl's DynaLoader documentation for +more info on how dynamic libraries are found. +
On UNIX:
+
We are currently working on a UNIX makefile. Please contact
+me for more details.
+