lisp | Toy Lisp 15 interpreter | Interpreter library

There isn't a Genera topic on stackoverflow, but I thought I'd take the chance that one of the (probably) 5 people in the world using it might be here; no harm in trying.

I've run into the situation where a few of the systems I'm working with use pretty printing, which is not implemented on Genera. I've managed to work around the problem in my own system by using the predecessor of pretty printing, XP. Looking at the code in xp-code.lisp and comparing it to that in CCL, it's clear where CCL got its pretty printing functions from.

One solution, now proving inadequate, is to have a top-level eval that does an (xp::install :package my-package) and resume from the redefinition warnings. The problem is that when one of the third-party systems is compiled, they too complain about pretty printing features that are not implemented, so I'd have to install XP in each of these other packages that want pretty printing.

What really needs to happen is for XP to be installed in the common-lisp package, because all of these other systems are going to :use :cl and expect to have a fully functional pretty printing system.

That's not so easy though; the CL package is locked and each XP symbol requires multiple confirms, and a type 'yes', to get it into the CL package. The documentation for External-only Packages and Locking suggests that:

To set up an external-only package, it can be temporarily unlocked and then the desired set of symbols interned in it

but no where does it say how to unlock a package, and the Document Examiner isn't turning up much.

I also have to stop and wonder if I'm barking up the wrong tree. XP was written with Genera in mind, and there are conditionalisations in the code for the platform. It shouldn't be so hard to install using the install function; and I wonder if I'm missing something obvious.

Does anyone out there know how to unlock the CL package, or the proper way install XP in Genera? The included instructions for XP appear to be out of date.

I am trying to encode a small lambda calculus with algebraic datatypes in Scheme. I want it to use lazy evaluation, for which I tried to use the primitives delay and force. However, this has a large negative impact on the performance of evaluation: the execution time on a small test case goes up by a factor of 20x.

While I did not expect laziness to speed up this particular test case, I did not expect a huge slowdown either. My question is thus: What is causing this huge overhead with lazy evaluation, and how can I avoid this problem while still getting lazy evaluation? I would already be happy to get within 2x the execution time of the strict version, but faster is of course always better.

Below are the strict and lazy versions of the test case I used. The test deals with natural numbers in unary notation: it constructs a sequence of 2^24 sucs followed by a zero and then destructs the result again. The lazy version was constructed from the strict version by adding delay and force in appropriate places, and adding let-bindings to avoid forcing an argument more than once. (I also tried a version where zero and suc were strict but other functions were lazy, but this was even slower than the fully lazy version so I omitted it here.)

I compiled both programs using compile-file in Chez Scheme 9.5 and executed the resulting .so files with petite --program. Execution time (user only) for the strict version was 0.578s, while the lazy version takes 11,891s, which is almost exactly 20x slower.

could you guys please help me creating a next and previous buttons ? I've been struggling because of my bad javascript . I saw some people use Jquery and almost all Javascript. I'm practicing Javascript so there are a lot of things I don't know. Thank you very much.

Wants: Next / Previous button to go to next page and go back page if users want to read again that page.

Link of my demo: https://jsfiddle. net/hioihia123/zgjswtay/3/

I do not understand this:

In Scheme, the function f below is not visible outside its enclosing let:

Say that I am connected to a remote Lisp using swank/slime. I have a data file on my local machine on disk or, perhaps, in an emacs buffer. I want to process this file using the remote Lisp.

I can obviously drop out to a shell and scp the file to the server, load the file, process it, close, delete the file so that I don't make a mess on the server.

I can also paste the file into the repl:

I was playing around with Haskell's parsec library. I was trying to parse a hexadecimal string of the form "#x[0-9A-Fa-f]*" into an integer. This the code I thought would work:

In the source code of SBCL's y-or-n-p, I see (declare (explicit-check)):

As an attempt to learn more about call/cc in general I saw How does the yin-yang puzzle work? question and this explaination about the yin-yang puzzle: