pharo VS Smalltalk

Smalltalk (https://pharo.org/)

Smalltalk also did this. These days my impression is the most active tendril is https://pharo.org/.

What I find especially interesting about that relative to this Python distro is that the Pharo executable runs in a host OS (e.g. whatever your daily driver is) and can maintain different image files for different Pharo system states. So not only do you have the integrated language/OS (which is very cool on its own), but you also have something that feels like Docker containers.

And it even goes beyond containers because those image files really are the state of the system at the time they're saved, which means you can ask for that file in a bug report and get guaranteed bug reproduction, which is pretty incredible.

It is the initial alpha release end-user can test. It is a complete port from Pharo to Cuis-Smalltalk. Likely bugs will be find.

I've recently started learning Pharo^1 and I think there is a lot to like about it. It hurts to say as a Lisp and Emacs fan, but using the Pharo IDE feels like using Emacs/extending Emacs with Emacs Lisp, but somehow with a more tightly integrated language and environment. Being able to easily inspect the code related to the UI widgets, modify it and make changes on the fly are unlike anything I've experienced in other languages. I think a whole OS built on top of Smalltalk would be so cool and really play into the strengths of Smalltalk. I'm also amazed that SmallTalk had a lot of these IDE like features since before the 80s^2. I know there are a lot of issues with image based languages, and I admit I haven't been using one long enough to have experienced all the Gotcha, so what does HN think of Smalltalks and it's derivatives, and what are you all doing with them?

1. https://pharo.org/

2. https://youtu.be/uknEhXyZgsg?t=2366

Cool! I program for around 7 months in Pharo now at Yesplan [0]. We're hiring a devops engineer and a software engineer. While the Pharo website [1] avoids mentioning it, it's a Smalltalk descendant.

What I like about Pharo:

1. Programming in the debugger makes things feel much quicker

2. Evaluating expressions inside your code editor makes programming feel much quicker

3. The ability to quickly browse classes and methods makes programming feel much quicker (e.g. I type Date somewhere, select it, press CMD+B and now I browse the Date class).

Don't get me wrong, Pharo has downsides, especially when it comes to using it in production (IMO). With that said, the language feels fun to use! I definitely like it now as my first language for side projects as it is more graphical, more playful, and feels quicker for iterative development (e.g. when consuming APIs). It's why I wanted to learn it in the first place, it has shown me a different philosophy on how programmers interact with a programming language and IDE.

[0] https://yesplan.be/en/vacancies

[1] https://pharo.org

Of course, Alan Kay's Smalltalk 80 is for many the quintessential lost paradise of personal computing. Some modern descendants are Squeak, Pharo and Cuis. Then there's Lisp machines, or for something more Unix-like, there's Plan 9.. so many cool systems deprived of mass adoption for no good reason.

> You know, that "assembling things live in the sky" Lisp feeling (Yegge's phrase, not mine). The only other computation environment that is right there en par in flexibility and conveyance of the same trippy feeling is, of course, Emacs.

Do you know Pharo? The experience you describe is also typical in the Smalltalk family. See https://pharo.org/

Smalltalk could be used as the "ideal" tool (balance between Code & No-Code). It starts out with a simple graphical interface for doing everything, but it also encourages you to customize everything by modifying the underlying code. Of course, the disadvantage is that it's quite niche - very few people actually use it nowadays.

In Smalltalk there is no such thing as source files. Your program is an image which can be freely modified and dumped. Look at Pharo[1] which is a modern Smalltalk environment. You start it up and create classes in the IDE, but never do you create "source files".

[1] https://pharo.org/

> * I'm assuming the "by the Bluebook" implementation they're referring to is this: *

Or this: https://github.com/rochus-keller/Smalltalk/

> message passing and late binding combined. "Duck typing" is seriously diminishing it

Actually even ST-72 made synchronous calls, but at least with a token stream interpreted by the receiving object (thus at least a bit of "message passing"). In ST-76 and later versions "message passing" is just nomenclature used by the ST folks for something that is just ordinary method dispatch and call (if you have doubts, you can analyze the innards of the ST-80 VM yourself e.g. with these tools: https://github.com/rochus-keller/Smalltalk ). The major difference is the dispatch based on signature hash (similar to e.g. Java interface method calls) instead of static positions, which enables late binding (at the expense of performance); and since everything including ordinary integers derive from Object, all values and objects are subject to dynamic method dispatch; it's no coincidence that Smalltalk was the first language to allow real duck typing. The unification of scalar values and references, dynamic typing, and likewise the minimal syntax where control structures are implemented by means of runtime constructs were already known from Lisp; also closures (i.e. ST blocks) were already known before they were added to ST.

Here is one even in Lua: https://github.com/rochus-keller/Smalltalk/

> 10kSLOC for the entire universe

It is the nature of idealists that they see the world idealized. Smalltalk-80 itself has nearly 30 kSLOC; it's just more difficult to count, but I wrote tools which can do it (https://github.com/rochus-keller/Smalltalk/).

Why should "perform" be a message? It's just a method of the Object class, which is the superclass of Integer. You can use my St80ClassBrowser and St80ImageViewer (see https://github.com/rochus-keller/Smalltalk/) to check the ST-80 source code and image if you want; there is a list of all selectors and the classes which implement them. Going up the class hierarchy when doing virtual method dispatch is a fundamental concept of all object-oriented implementations; in contrast to e.g. C++ this can be done dynamically at runtime in Smalltalk or Java (which is also called late binding). In contrast to Smalltalk in Java the class loader verifies that a method for the referenced signature actually exists; in Smalltalk you can try to dispatch any signature which can result in a call to the doesNotUnderstand method of the Object class.

> a large lua game code base, over 4000 files, 1.5 million lines of code

Interesting; how do you manage to keep consistency? Do you have special tools to e.g. detect inadvertent global variables? I once wrote a Smalltalk VM in Lua (https://github.com/rochus-keller/Smalltalk/blob/master/Inter...) which is a much smaller code base but even with this size I quickly would have lost track of e.g. scopes and names without tools I had to write myself (https://github.com/rochus-keller/LJTools).

It is true, that there is uncollected garbage in the original Xerox ST80 image. I've built some tools to analyze the image and also a VM which can be interrupted at any time to analyze the current state of the image (see https://github.com/rochus-keller/Smalltalk).

There are two zombie processes (OID 6662 and 19ba). There are also a couple of BlockContext and MethodContext which have a nil sender and a reference to an unknown method, but which are still referenced from somewhere (i.e. the collection is prevented even if it is not implemented by reference counting. E.g. OID 79a2 of class BinaryChoice. I have a full list if anybody is interested.

Integers are actually directly stored, i.e. without boxing/indirection by a pointer. The Smalltalk object memory doesn't have pointers in the C sense, but rather indices into the object table. If you're interested I've implemented a couple of tools to study the original Smalltalk-80 VM, see https://github.com/rochus-keller/Smalltalk/.

- https://github.com/rochus-keller/Smalltalk/ Parser, code model, interpreter and navigable browser for the original Xerox Smalltalk-80 v2 sources and virtual image file

- https://github.com/rochus-keller/Som/ Parser, code model, navigable browser and VM for the SOM Smalltalk dialect

- https://github.com/rochus-keller/Simula A Simula 67 parser written in C++ and Qt

> do you regret those endeavours?

No, not in any way; the projects were very entertaining and gave me interesting insights.