On 5/4/17 May 4 -4:23 PM, Faré wrote:
On Thu, May 4, 2017 at 4:52 PM, Robert Goldman rpgoldman@sift.net wrote:
On 5/4/17 May 4 -2:34 PM, Faré wrote:
In any case, friends don't let novices use the central-registry.
The counter-argument to this is that *central-registry* is much more conceptually simple and easier to debug than the new configuration framework.
The problem with central-registry is a bootstrap problem. It requires everyone to be a system administrator and edit configuration files.
I don't follow this claim. All central registry requires is that you run some lisp code, generally in your lisp-init file.
If I write code that populates my *central-registry*, I can trace that code and I can look at the *central-registry*. It's as easy as (PPRINT asdf:*central-registry*)
But to write that code, you must be an expert who can intercept CL configuration and be productive in that bootstrap environment.
Again, I don't get this. We have one piece of lisp code that does a simple depth-first search and jams things into ASDF:*CENTRAL-REGISTRY*. People stuff that into their lisp-init files and that's it.
You are right, of course, that we can do that with INITIALIZE-SOURCE-REGISTRY, too, but I don't understand your claims about needing root privilege or needing to understand the bootstrap environment any more than just understanding how to write a lisp-init file.
But then you can just as well call (asdf:initialize-source-registry) and inspect the contents of asdf::*source-registry* or what is returned by (asdf/source-registry:flatten-source-registry), or trace functions in the source-registry. But mostly you don't need to, because it just works out of the box without configuration.
At least in the past, if you added a new asd file to a directory in the *central-registry*, then ASDF would find it. If you add it to somewhere covered by the new configuration framework, it won't, will it? because the new configuration framework eagerly searches for asd files.
(Admittedly, *central-registry* scales poorly for very large programs).
You may indeed need to re-run (asdf:initialize-source-registry) after you install or remove .asd files. That is documented, and a small price to pay for scaling the registry much beyond what the *central-registry* will crumble with.
It's a small price to pay IF YOU NEED TO SCALE THE REGISTRY BEYOND WHAT *CENTRAL-REGISTRY* WILL CRUMBLE WITH. Otherwise, it's an annoyance created by an optimization you don't need.
The largest project I'm working on now has 212 entries in ASDF:*CENTRAL-REGISTRY*. Could be zippier, but that certainly doesn't cause the list representation to crumble.
I get it that the new structure scales better, but it is a tradeoff, and some users will find that it's not a tradeoff that works for them.
For the new configuration arrangements, things are much more difficult for a novice to understand. The actual configuration is held in tables that are opaque (yes, they can be dumped, but it's non-trivial and not discussed in the manual).
A novice does not need to understand it. If you follow the instructions, such as "install your software under ~/common-lisp/", then it Just Works™.
That doesn't work if you work on multiple different systems that have different source repositories. I typically work on at least three different CL projects at once, which means a single configuration is a non-starter for me.
Experts can dump tables. I hesitated about replicating alexandria:hash-table-alist in uiop, to make it easy to dump some tables. Decided against it in the end, but if you believe novices should be able to dump those tables, that's something to consider.
Yes, I do believe that novices should be able to dump those tables, because I have seen novices make mistakes (e.g., having both lisp code configuration and a .conf file configuration -- the former being added after the latter was forgotten), and just be completely confused and lost.
But in addition to dumping the tables, everyone must be able to figure out where the table entries came from. That's why something like tracing is so important. Again, if anyone, including a novice, gets their configuration messed up -- and, indeed, novices are very likely to, because they often just cargo-cult configs from others -- they need to be able to see where that configuration comes from and how to fix it.
The current "there's more than one way to do it" configuration process means that this is especially important, because we can no longer simply look in our lisp initialization to figure out why things have gone up the spout. Instead, we have to check hidden configuration directories, environment variables, lisp code, etc.
Much of the configuration code cannot be traced because key operations take place in side-effecting anonymous lambdas.
That code is not the most readable, but what it does it well documented, well debugged, and it's easy to look at the result, change something and look at the result again.
Only if you know where the configuration was that needs to be changed. I have definitely seen people who have configurations slopped all over the place, some forgotten, and had to try to help them debug.
Finally, if you configure with configuration files in your XDG config directories, there's not even a chance to trace, because by the time you could set up a trace, the configuration's been loaded.
It doesn't actually make tracing harder than usual. Tracing asdf configuration is a normally hard bootstrap issue.
Not if the configuration is in your lisp code it isn't. Only when we added the configuration files.
In short, while the new configuration structure is better in many ways, that's only if it works. If something odd happens, it leaves you pretty flat. If you have a small set of libraries in use, *central-registry* can be a lot easier to deal with.
On the other hand, the source-registry often "just works" out of the box, or requires a one-liner to configure. The *central-registry* is cognitively much heavier, especially so on novices.
My philosophy is to assume that code will always break and then consider how people can recover from that. So yes, I agree, ASDF now typically just works, but we haven't left users with much support when it doesn't.
I've been meaning to provide more debugging to the configuration process, but just keeping up with everyone else's mods to ASDF has eaten all the ASDF time I have for now.
That would be a good thing.
When you have time, a post hoc review of the changes from 3.2.0 to 3.2.1 would be nice. Also a review of the plan branch, and some opinions on what to do about syntax-control and when.
Will do. I'm just nudging up from half time, though, so I'm moving slowly. And maybe I need to prioritize something I want to do (the debugging utils) over chores, or I'm just going to end up hating to work on ASDF....
Please note that I don't think what you did was bad, I just think that it can on occasion leave people flat, and I would like to work to help them when that happens.
best, r