Re: Naive DEFSYSTEM replacement

On 26 Jul 2025, at 19:55, Adam Weaver (as adam at cleversure dot com dot 
au) wrote:

> Anyway, thanks Tim. I'm going to go back to ASDF, because I do like 
> its
> configuration file format. And although MK:DEFSYSTEM looks interesting
> too, ASDF2 is the one bundled with LW. And I'm wedded to LW.

One big advantage of ASDF over `MK-DEFSYSTEM` is the key Dan Barlow idea 
of using `*load-truename*` to find the source files for a system.  
`MK-DEFSYSTEM` still leaves you without any way to load libraries 
without laboriously setting up logical pathnames or something.  I 
remember the bad old days when if you wanted to install a new system, 
you had to edit a bunch of files to tell CL where to find the source.

Honestly, in the bad old days before ASDF there really were not commonly 
used libraries in the CL world!  I can remember when almost the only 
libraries were code libraries shared among members of a single lab.  Or, 
as in the case of *Paradigms of AI Programming*, one set of source files 
for a single textbook.

Not 100% true, but mostly true.  It's hard to overstate how important 
Barlow's development of ASDF was to the CL community.

For example, here's a piece of the Garnet graphical UI system:

```
;;; This file basically moves all of the moving parts of garnet-loader
;;;into one place, it also establishes a few other options which may
;;;be useful when working in Garnet.   As the corresponding constants
;;;are defined in garnet-loader with a defvar statement, you can
;;;modify this and then load garnet-loader.
;;;
;;;

;;; This next variable should be set to the location of all
;;; garent sources, libs, binaries.  If for some reason this load form
;;; does not work for you, set this variable appropriately.  This form
;;; is also loaded (as a defvar) in garnet-loader so you can comment
;;; this line out if your config-garnet is in a different directory
;;; than your garnet-loader.
(setq Your-Garnet-Pathame
   (namestring (make-pathname :directory
			     (pathname-directory *load-truename*))))
```

This is for a system that has *no external dependencies*. Now imagine 
trying to assemble a set of libraries as in modern programming, where 
there might be dependencies you don't even know!  No ASDF: no quicklisp. 
  It would be like Python without PyPi.