Interactive Common Lisp Development(n16f.net) |
Interactive Common Lisp Development(n16f.net) |
- https://www.youtube.com/watch?v=jBBS4FeY7XM (5min) my demo to show how to resume execution of a long running program, from the stack frame right before the bug, after having fixed and recompiled the function, without quitting the debugger hence without stopping the program, thus without restarting everything from zero.
- https://www.youtube.com/watch?v=nsKx40ab9SY (20min)showing what saving and restoring an image does, differences between SBCL and LispWorks.
- https://www.youtube.com/watch?v=1aboMZkNDCY developing a 3D graphics software.
- https://mikelevins.github.io/posts/2020-12-18-repl-driven/
- debugging CL tools: https://lispcookbook.github.io/cl-cookbook/debugging.html
- and no: while we could deploy a ball of mud to production, we can also not and use traditional tools and techniques: build an executable from scratch, restart the app, reload state. But we can do everything in between too (inspect the running app, change it a bit, change it a whole lot (while staying in sync with local source code), use images to speed-up development etc).
Thanks for the links.
For many Common Lisp scenarios, it's actually similar -- start with the raw based image, load in your code and data, snapshot it, and ship the resulting artifact. At least for me, interactive development aside, it's not untoward to restart a CL system from scratch as a routine part of development. We're not running on Lisp Machines anymore where restarting was actually quite expensive (though there were anecdotes about how at some point it was faster to restart a LispM than let it grind through its GC process, I don't know about that).
However, I don't know how common that is with Smalltalk. How often they restart from scratch. Saving the image is routine in Smalltalk. Where in Lisp you CAN save the image, it's not necessarily part and parcel operationally, historically, or culturally to constantly save the image, especially post LispM. In Smalltalk it is.
I think with CL folk moreso build a new base image, load in some routine utilities, etc. to form a baseline. But application code and image are separate.
Smalltalk, they're not. Code is part of the image (it's stored separately, but it's presented as if they're one and the same). So the image is a much more first class citizen in the Smalltalk world, rather than, perhaps, an artifact.
Especially today, I imagine they have build processes that build up the entire thing again from scratch, but it would not surprise me if they bumped into problems where the image and the source code "don't quite match" that they have to suss out in testing before deployment, because something slipped through and tweaked the long saved image that wasn't properly captured.
In any case, while I'm sure it doesn't quite happen like that today, its not unreasonable to have someone ship a "ball of mud" Smalltalk image in contrast to one in CL.
Is anyone aware of SBCL or LispWorks-based tooling that integrates with ServiceNow CHG records to record and perform these kinds of changes to automatically create an audit trail of such changes in a CHG record as the Lisp image is manipulated for emergency changes?
I'm certain that emacs/slime is the true pure way, but for someone who's not wanting to learn emacs, alive is just pretty amazing and magic, and it fits well with what is described in the article. I wish I could do stuff like recompile functions in-place and just retry the call without exiting the process in every language in this way.
https://lispcookbook.github.io/cl-cookbook/vscode-alive.html
Yes there are a lot of content. Just the topic is …
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btw, regarding packages and removing a symbol: uiop:define-package fixes the annoyance.
It's been my hope for well over a decade that the situation would change. Alive is decent, but has a long way to go before being a tool a professional could reasonably use.
Im curious why you think this is the no.1 issue? I think a bigger issue is that so many CL programmers prefer to talk about lisp instead of just getting their hands dirty and making cool original open source things with it that other people would get excited to use. Thats actually a much harder problem. Plenty of people actually use Emacs even if they dont care for elisp and end up learning and writing elisp because they like Emacs. I think CL should market itself to uni or even high school students. Kudos to you though! You are doing great work to promote CL
The tooling is nice, but it’s not what defines CL. The language has ample benefits just on its own.
A paren matching editor is the minimum tooling necessary for CL. Auto indent is a nice to have. vi has had both for pushing 50 years now.
The REPL is a standout feature of the system. Being able to load your code and poke at it is wonderful. Very powerful feature.
Python has a REPL. I never felt it was very good, but that’s me. I never used it much. Perhaps I was missing something. I wrote a bunch of Python without ever using it. And I’d wager many coders have treated Python like they’d have treated Perl, or most any scripting language. Write code, save code, run script, rinse, repeat.
With no interim step, turn around was fast and work got done.
There is nothing stopping folks from doing the same with CL. I’ve developed 1000s of lines of CL with little more than 2 little defuns. (e) and (l). (e) fired off ‘vi code.lisp’ and (l) wrapped ‘(load “code.lisp”)’. My knowledge of the debugger was knowing how to abort it back to the top level. I mostly did “print” debugging. If I was clever, I’d write a ‘dprint’ function that would take variable arguments. If I was lazy, I’d just “(print ‘(“x=“ x “y=“ y))”. No big deal.
Even when working with LispWorks (which has much to recommend it), I operated much like this. Reload all the code, dabble with the REPL, add print calls, reload, test individual functions. I never took the time to learn the higher level tooling and such. I didn’t feel it was necessary, and I’d rather code than fight tooling.
So, as the Lisp cognoscenti stares on in mouth agape horror as I left much of the Lisp experience on the shelf, I got stuff done anyway.
Which goes back to the fundamental point. CL is a language like any other. It’s a very cool language, very powerful, and worth using just for itself. Its environment does not define it as a language. It augments it, it’s cultural and useful to be sure, but you don’t necessarily need it to be capable and productive and to solve problems.
If all the talk of tooling and what not deters you from trying the language, don’t let it. It’s worth trying all on its own. Try it your way, however you’re comfortable.
But do get a parenthesis matching editor.
Edit: just to highlight the point, if you read PGs “On Lisp” and “Common Lisp” books, you’ll notice they’re pretty much all about the language and its power. He does not talk much as I recall about the environment.
NN in general just boil down to doing lots of linear algebra, which is a lot about mutating very large matrices. For this you really just want a wrapper around BLAS/LAPACK, so you can leverage existing optimized libraries.
Working with matrices in Lisp always feels a bit clunky, and doubly so when you want to do a lot of stateful operations on them. The real compitetor in this space to Python is something like Matlab, which has probably the best interface for doing linear algebra (but is worse at everything else).
The one area where Lisp and Python both shine is the ability to perform automatic differentiation. Lisps are great for this task since it's all symbolic manipulation. However, this is only important once you have a solid interface for working with matrices.
If you want to get a feel for the difference I would suggest reading through the surprisingly excellent The Little Learner. I think you'll find that while it really demonstrates the power of Scheme (Racket in this case) in areas where it excels, you wouldn't want to use the framework in that book for anything other than toy examples.
Lisp can be at least as high level and expressive as any other language.
I love Lisp and Smalltalk, but I work as a machine learning researcher as my day job, and I code in Python at work. Admittedly I miss Common Lisp whenever I code in Python, and I think Jupyter notebooks are a poor man’s Smalltalk environment, but when comparing Python to C and C++ (and I used to work primarily in systems programming, so I know my way around C), Python is a major productivity boost.
CERN and Fermilab were adopting Python for Grid Computing (aka Cloud nowadays), already in 2003.
MIT changed SICP from Scheme to Python back in 2006, thus news generations started playing with Python.
Peter Norvig called Python an acceptable Lisp around 2010, in HN. Having written Python for Lisp programmers in 2000.
https://news.ycombinator.com/item?id=1803351
https://norvig.com/python-lisp.html
What bums me out, is the lack of JIT in the box (yes I know there are some alternatives).
last millennium when google started up, no lisp was a good option. clojure didn't exist, schemes were mostly for teaching, cmucl was in disrepair, and though there were proprietary common lisps, they were proprietary and wanted per-cpu license fees, which would have meant disclosing how many cpus google had—a closely guarded secret
moreover, common lisp's approach of putting a uniform but somewhat repulsive veneer over all operating systems was a pure drawback in google's all-linux environment, and s-expression syntax is harder to read than python's (if easier to edit)
also the python community was friendly and welcoming, while the scheme community was tiny and fragmented, and the common lisp community had degenerated into an ego trip for a world-class asshole named erik naggum
this is guessing from the outside; i've never worked at google, which is why i'm allowed to write this
I just learned today that another new GC for SBCL is in the works, with GC pauses under 100 microseconds.
Python doesn't have a standard, but it has a canonical implementation, so maybe a "defacto standard". Not having an official standard didn't matter, though.
Common Lisp has defacto "standard libraries" for things like threading. Other things, such as async, are less clear (to me), but libraries do exist. Just because something isn't in the standard, though, doesn't mean it can't exist. Also, implementation such as SBCL pick up a lot of the slack, filling in some of the missing gaps.
In early Lisp I would guess it was more often to save an image. There is one system which works mostly like Smalltalk: Interlisp-D, now called Medley. https://interlisp.org It also manages the code, in some ways similar to Smalltalk. Interlisp was provided by Xerox PARC, like Smalltalk. It originates from BBN Lisp, from the 60s.
Other than that, most Lisp systems store code in the file system.
> its not unreasonable to have someone ship a "ball of mud"
That's also relatively common (!) in Lisp.
In Smalltalk we often see variants which can ship images and run them on different architectures. In Common Lisp images are mostly tied to a certain architecture & OS.
"Cattle" is what I usually hear. Pets are unique and cannot be interchanged. Cattle are fungible and expendable.
For batch mode you can run script. Using format print :-). But in real life when you encounter problem the great thing of lisp is you can curl-c and inspect what is going on. I just doing my study of cl-6502 and found that this interactive nature and the readable of lisp is invaluable.
For interactive mode you can do rely upon emacs (or ccl which I cannot use for look like a decade now due to sudden issue; finally resolve this using xaddr) or vim (google vim lisp lead you there) where you can load an image and then interactive with it.
Why it stop here in my script? Just inspect around.
Now this is somewhere possibly this article in the interactive mode to see how symbols, … etc might be useful. The problem I have (I just read it the third times trying my best to appreciate) is that it does not lead you to anywhere. If you do not know these the article does not help. If you do, it does not help much as it is not going deep enough.
Perhaps an interactive session or information how interaction and use of this concept in a future article might be useful. By this article alone more is expected when one read that.
Just in case I am definitely no better than him on lisp. I just expect to stand on another “giant” shoulder to learn more about this lisp approach. Sorry if I think it shortfalls a lot.
Best regards and let us move on. Good days.
s-exps are basically coding at the level of the AST, which for many programming tasks is a powerful level of both abstraction and control.
But this interface tends to work much better on tree-like structures (the most simple of which is the list, which in it's simplest case is a cons cell, Lisp's most fundamental particle).
Most programming tasks can boil down to tree manipulation, but large matrices feel a bit out of place with this interface because you are basically to working with arrays (which in it's simplest cases is a pointer to a memory address, which is C's fundamental particle). C like languages (I know, technical ALGO-like), tend to feel more natural for these tasks.
But of course if you can manipulate trees easily, you can manipulate code easily which gives you...
> Lisp can be at least as high level and expressive as any other language.
In practice, for Lisp this is also a weakness. Again, I love Lisps in general, and of course any Lisp and especially Common Lisp (with it's exceptionally excellent macro system) can do anything you want.
However, my (and many others) experience has been that this leads to is it becomes very easy to create code that is amazing for the original developer, but very difficult for new developers to get their head around. Hence the adage "Lisp is optimal for team sizes of one."
You could undoubtable build the worlds most elegant interface to working with matrices in Lisp, but now you essentially have a new language.
[1 2 3; 4 5 6; 7 8 9]
#2A((1 2 3) (3 4 5) (7 8 9))
[[1,2,3],[4,5,6],[7,8,9]]
julia> [1,2,3] # An array of `Int`s
3-element Vector{Int64}:
1
2
3
julia> [1:2, 4:5] # Has a comma, so no concatenation occurs.
2-element Vector{UnitRange{Int64}}:
1:2
4:5
julia> [1:2 4:5 7:8]
2×3 Matrix{Int64}:
1 4 7
2 5 8
julia> [[1,2] [4,5] [7,8]]
2×3 Matrix{Int64}:
1 4 7
2 5 8
julia> [1 2
3 4]
2×2 Matrix{Int64}:
1 2
3 4
julia> a=[1 2 5 8 9; 3 4 2 1 33]
2×5 Array{Int64,2}:
1 2 5 8 9
3 4 2 1 33
> You could undoubtable build the worlds most elegant interface to working with matrices in Lisp, but now you essentially have a new language.
What?
Since we're in lisp, you can imagine some macros that make working with matrices easier!
So much stuff has changed since 2013. Containerization, massive increase in concurrency, mobile platform explosion, etc. Where is the concurrency standard ? Are these 14 CDR's even implemented by CL implementations ? Can't find which CL implementation implements priority queue. Several of those CDR's don't even appear active.