- Passing parameters to ECL and getting results from ECL
- ECL Objects
- SEE ALSO
- COPYRIGHT AND LICENSE
ecl - Perl extension for ECL lisp
use ecl; my $cl = new ecl; my $r = $cl->eval("(format nil \"[~S]\" 'qwerty)"); my $lam = $cl->eval("(lambda (x y) (+ x y))"); $lam->funcall(5,9); # results 14
ecl is a bit easier to use than Language::Lisp because of embeddable nature of ECL lisp. Language::Lisp uses different approach because they are other way down: Lisp calls Perl and not vice versa.
new method used to create
ecl object which is used to talk with underlying lisp. This object looks like an interpreter instance, although there is actually no interpreter instance created. Instead, this object is used to create a handy way of invoking API: given that you have
$cl object you can execute:
my $res = $cl->eval("(format nil \"~A\" (expt 2 1000))");
which is equivalent to
my $res = ecl::eval(undef, "....");
but is much better to use.
Required Perl objects converted to Lisp objects and vice versa. Compatible types are converted as-is (e.g. ECL type t_integer becomes SvIV), all other types are blessed into some package, for example into
This is done behind the scenes and user should not bother about this.
This makes following code to work:
my $lam = $cl->eval("(lambda (x y) (+ x y))"); print $lam->funcall(40,2); # prints 42 print $cl->funcall($lam,40,2); # ... another way to say the same
runs string within ECL interpreter and returns whatever lisp returns to us. Internally this transforms to the call
same as eval but takes lisp object instead of string as argument.
returns LISP keyword as a symbol (from Perl side this means it is blessed to
ecl::Symbol package). In Lisp this symbol belongs to the 'keyword' package. These keywords correspond to lisp's
given lisp object blessed to package ecl::Code calls the procedure.
(prin1 (perl-ev "join (',','a'..'z'). qq/hello!/" ) )
$cl->someFunctionName(args) get transformed into function call to "some-function-name"
This is done by finding lisp object for evaluating arguments, and blessing it into ecl::Code package
LISP symbols are blessed to this package
Object to represent character type within Lisp. Here are 3 equivalent ways to get it:
$ch = $cl->char("c"); $ch = $cl->char(ord("c")); $ch = ecl::_char("c");
Another way is:
$ch = $cl->eval('#\c');
If you have a list object in Lisp, it will be automatically blessed into the
my $list = $cl->eval("'(a b c d qwerty)");
List object have
item(n) method to return n-th value from the list.
List object have TIEARRAY, FETCH, FETCHSIZE methods and so ready for tie-ing as array with a
tie perl funciton:
tie my @arr, "ecl::List", $list;
Even simplier, $list have
_tie method to return tied array reference:
my $arr = $list->_tie;
Fetching items from this array works, storing them currently do not work.
None. No namespace pollution, the greens are happy.
ECL uses Boehm GC, and at the moment of writing it did not had reliable interface on returning memory to GC, so the leaks of memory are unavoidable.
funcallcan not take more than 10 args - this should be fixed.
See ecls.sf.net to read about ECL lisp project. See github.com/vadrer/perl-ecl
Vadim Konovalov, <firstname.lastname@example.org>
Copyright (C) 2008 by VKON
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.004 or, at your option, any later version of Perl 5 you may have available.