Esto compila sin error pero debería arrojar uno.

Here is a hint that individuals, as the minimal embodiement of potential action, can be collaborating objects too

Proposal

Its internal collaborators are the main protagonists of the game.

Suggest removal

entrypoint

I'd rather stop using “states” and start talking about ”internal collaborators“. For example:

After discerning the classes that our game needs, we can now assign them responsibilities and internal collaborators:

Plural

Select the odd numbers between -20 and 45.

ProtoObject new enters an infinite loop in Cuis University 5981. Fixed in Cuis.

The goal is not computing efficiency but flexibility, scalability, simplicity, readability; that is, the goal is human efficiency.

Vector Graphics is actually what got the Cuis project started. In 2003, ten years before the Retina display, I (Juan Vuletich) decided that making Morphic zoomeable and independent of pixel resolution would require completely abandoning back compatibility with the existing Morphic in Squeak. I took Squeak 3.7 and started working on what would later be named Cuis Smalltalk.

—Juan Vuletich, Vector Graphics and Morphic 3

Why use “rect” as an abbreviation for rectangle? Is confusing since it has another meaning.

I think I came up with this slogan at Parc during discussions wrt children, end-users, user-interfaces, and programming languages. Chuck Thacker (the genius behind the Parc hardware) also liked it and adopted it as a principle for many of his projects.

Alan Kay's answer at Quora.

Link to or mention the Cuis Smalltalk terse guide

For some reason, before reading this, I misunderstood the “cascade” as a metaphor for composition, were the water fallen from a first cascade might flow as input to a second cascade; but now I see this is clearly wrong and the cascade means exactly the contrary, since the punctuation :: and ; breaks that continuity. It means a jump in the regular flow of evaluation, as a cascade means a jump.

The double colon syntax is specific to Cuis; at least it is not valid syntax in Squeak.

Include a note about specific Cuis idioms, explain why they exist, and link to discussion and documentation: * backticks for compound literals * double colon as an alternative to parentheses * #[aFloat] for Float64Array * #[anInteger] for ByteArray

See the thread Language Constructs initiated by Erik Stel in the Cuis-dev mailing list in 2020-05; especially the answers by Juan Vuletich.

Backtick compound literals

... In some cases it can improve performance or reduce memory usage. But the deeper reason is to put all classes in equal footing with those privileged ones that are known by the Compiler.

More here

Maybe include a link to its usage in https://cuis-smalltalk.github.io/TheCuisBook/Back-to-Spacewar_0021-Morphs.html#index-backtick

A source of confusion for beginners is why binary messages exist in the first place when they could be implemented instead as keyword messages taking one argument as #lcm: and #gcd:; you could in fact, imagine an alternative syntax with only unary and keyword messages, but it would be cumbersome to read and write. Binary messages improve legibility without introducing too much complexity for the implementors.

At this point, where classes have not yet been discussed, maybe it is best to rewrite:

the object Transcript

Given that there is no way we could pay back the creators of Smalltalk for their immense gift, Cuis is our attempt to pay it forward. Yes, it is a work of love. — Juan Vuletich, Cuis-dev mailling list 2020-04

the tradeoffs

This should go in the previous section Daily Workflow.

I submitted a PR

Sometimes I see the cuis looking righ, but sometimes a panda looking towards my left and upwards.

Oral History of Adele Goldberg, Computer History Museum, 10 May 2010 and its video recording at YouTube; and its artifact page at The CHM web site.

Maybe link to the search? https://github.com/search?q=Cuis-Smalltalk+-org%3ACuis-Smalltalk&type=repositories

Do we really need to read a discussion on the origin of this sentence?

If this is a rethorical device, I'd prefer to replace it.

Moved up to CharacterSequence. The categories are: fileman-converting, fileman-testing, and fileman-accessing.

“synch” is an alternative spelling sanctioned by dictionaries. I wouldn't mind using this expression colloquially but in the context of a book perhaps I can find a better way to rewrite this. Not very important.

This is an excellent opportunity to link to an official video showing how to use the debugger.

The mention of Morphs is pertinent as an example because they were discussed recently and moreover, because they are blatantly visible and reactive. The mention of “‘data objects’” between double quotes, on the other hand, doesn't bring much to the table and is potentially confusing.

Proposed alternative

As Morphs and objects in general, are able to present themselves to be inspected, so is Smalltalk’s runtime state also presentable.

Design Principles Behind Smalltalk. Byte Magazine Volume 06 Number 08, 1981-08

The fragment follows:

This criterion is well supported by the model of communicating objects. By definition, each object provides an appropriate message protocol for interaction. This protocol is essentially a microlanguage particular to just that kind of object. At the level of the user interface, the appropriate language for each object on the screen is presented visually (as text, menus, pictures) and sensed through keyboard activity and the use of a pointing device.

An earlier version of the reactive principle is:

The salient feature of Smalltalk is that all objects are active, ready to perform in full capacity at any time. Nothing of this liveness should be lost at the interface to the human user of the system. In other words. all components of the system must be able to present themselves to the user in an effective way, and must moreover present a set of simple tools for their neaningful alteration.

—1976, The Smalltalk-76 Programming System Design and Implementation

Again, explain why do we have to send #doOneCycleNow once more.

As we changed several visual parts, we request one update cycle of the environment

Is not enough.

This is necessary for the changes to actually show. I'd add a footnote explaining why it is necessary.

This should go in the previous section The Package.

I submitted a PR.

Alternative implementation:

Smalltalk userInterface := UISupervisor ui. taskbar := userInterface taskbar. userInterface submorphs do: [:morph | morph delete] without: taskbar.

This is the recommended pratice to achieve reproducible and shareable artifacts, unless you want to ship your image like in the Docker meme:

In a discussion in the Cuis mailing list, many people share their different approaches when working alone and in collaboration with others. See the whole thread spanning from July to August, not just the linked mail.

Why not UTF-8?

Change

Alternative 1

Observe how each category —regardless of wether it applies to a class or to a method— of an extension is prefixed with a *.

Alternative 2:

Observe how class categories and method categories of an extension are prefixed with a *.

I prefer the alternative 2.

Proposed change along these lines:

Now we are facing a problem: we extended the Integer class with #printStringToc, however, because we didn't categorize it properly, this method addition is by default part of the Cuis-Smalltalk core system and its associated default change set instead of being part of TheBook

This is an example of adding a requirement to a package but it is difficult to understand

proposed change to “version number”

Then the problem is not keeping backups, and not the fact that we are working with an image.

The underlying file system? If so, why is this pertinent? Unless for example the image file gets corrupted, but if that is the case, say that instead.

What does this mean?

Look for the source. I'm pretty sure I've heard it on more than one video recording with a slight difference:

Change is easy, except for the “change” part.

substituted

The method category

Again, why basically?

Why basically?

Confusing paragraph. How does the first sentence relate to the second? How does the second relate to the third?

Alice's Adventures in Wonderland

All these could be a single footnote.

https://rmod-files.lille.inria.fr/FreeBooks/CollectiveNBlueBook/morphic.final.pdf

https://handbook.selflanguage.org/2017.1/morphic.html

I don't see a need for two examples of #ifTrue:ifFalse.

Smalltalk divisors := [:m | (1 to: m) select: [:n | m isDivisibleBy: n]].

Yet, there ought to be better algorithms to compute divisors.

In many cases it is possible to read the vertical bar “|” the same way it is used in standard mathematic notation, I.e. you can read [ :n | n isEven ] as “n such as n is even”.

just sends the #allClasses message

Insert comment about full closures and what they enable compared to non-full closures.

This is the reason why we have an idiom consisting of semicolon separated messages, usually ending in #yourself.

TODO: Build the html from the texinfo sources locally in order to find out why there is an extra empty bullet point at the begining of this itemized list, and verify if this still happens.

Until now there is no obvious design need to use a two-sized Array. There could just be a needle and a wedge. However it might prove useful to keep them in a collection if we need to perform computations on both bodies.

Two-player game, singular!

SpaceWar! is a two-player game,

with #associationsDo we can dispense with the variable colors and moreover, we don't look the dictionary up for each key: Smalltalk {#red -> Color red. #blue -> Color blue. #green -> Color green} asDictionary associationsDo: [:association | association value: association key asString capitalized]

there are also #add:afterIndex and #add:beforeIndex

Smalltalk 'buenos días' union: 'bonjour'

Smalltalk (1 to: 100 by: 2) reject: #isPrime

Smalltalk (7 to: 100 by: 7) asArray

Smalltalk ((101 to: 200) select: #isPrime) size

Smalltalk ' ' join: ('Hello My Friend' substrings allButFirst)

has the problem that it doesn't stop at the first substring, so if you don't know the argumento to #allButFirst beforehand, you have to find it:

Smalltalk | sentence wordToRemove | sentence := 'Hello My Friend'. wordToRemove := sentence indexOf: Character space. sentence allButFirst: wordToRemove

And additively: Smalltalk (1 to: 24), (76 to: 100). You don't need to add #asString because #, relies on methods that use #species and an Interval species is Array.

I don't think that -> was introduced before as a shorthand for associationts, tuples, cons pairs. For example: Smalltalk Association key: #red value: Color red can be rewritten as: ```Smalltalk

red -> Color red

```

Observe how pi which was added last, is shown first, because of how Set >> #add: is implemented.

How to add ’Orange’ after ’Apple’ and before 2@1 in coll1?

or alternatively:

How to insert ’Orange’ between ’Apple’ and 2@1 in coll1?

The Abstract Class Pattern

Intent

Define the interface for a hierarchy of classes while deferring the implementation to subclasses. Abstract Class lets subclasses redefine the implementation of an interface while preserving the polymorphism of those classes.

—Bobby Woolf, 1996

Even more consice: Smalltalk (1 to: 10) collect: #reciprocal

Romans often wrote scriptio continua, that is, without word separators like spaces or dots.

Consider removal or rephrasing. Maybe rewiting ”For example, when searching...”, etc.

In this case we may also write in pont-free style Smalltalk (1 to: 100) select: #isPrime

Missing article

and a block of code

This looks more like a comment by the author.

Why start with “Therefore”?

See Unicode Support in Cuis Smalltalk and its presentation at Smalltalks 2022. See also the 2023-04-05 Cuis Smalltalk Meeting

Unclear choice of words. Maybe: “to two different or to a single object”.

“depending computational history” is also unclear.

Smalltalk 0 to: Float twoPi by: 1/10 do: [ :alpha | alpha cos print ].

Autocompletion is vastly improved by LiveTyping readly available in Cuis University.

Smalltalk String allMethodsInCategory: #arithmetic

My math background made me realize that each object could have several algebras associated with it, and there could be families of these, and that these would be very very useful. The term "polymorphism" was imposed much later (I think by Peter Wegner) and it isn't quite valid, since it really comes from the nomenclature of functions, and I wanted quite a bit more than functions. I made up a term "genericity" for dealing with generic behaviors in a quasi-algebraic form.

—Alan Kay Clarification of "object-oriented", email reply to Stefan Ram

Reductionistic vs other definitions

Is the annotated paragraph describing what is an object or how is an object? This same criticism is also present in Dave West's Object Thinking.

Other perspectives:

Smalltalk's design—and existence—is due to the insight that everything we can describe can be represented by the recursive composition of a single kind of behavioral building block that hides its combination of state and process inside itself and can be dealt with only through the exchange of messages. Philosophically, Smalltalk's objects have much in common with the monads of Leibniz and the notions of 20th century physics and biology. Its way of making objects is quite Platonic in that some of them act as idealizations of concepts—Ideas—from which manifestations can be created. That the Ideas are themselves manifestations (of the Idea-Idea) and that the Idea-Idea is a-kind-of Manifestation-Idea—which is a-kind-of itself, so that the system is completely self-describing— would have been appreciated by Plato as an extremely practical joke.

—Alan Kay Early History of Smalltalk (1972)

So objects have something resembling agency, see the actor model.

OOP to me means only messaging, local retention and protection and hiding of state-process, and extreme late-binding of all things. It can be done in Smalltalk and in LISP. There are possibly other systems in which this is possible, but I'm not aware of them.

—Alan Kay Clarification of "object-oriented", email reply to Stefan Ram

I also like the complementary view that Gerald Sussman teaches on his video lecture 5A that informs chapter 2 and 3 of SICP; objects are a cheap way of modelling the world.

Cuis and Squeak share this same design but other dialects make LargePositiveInteger and LargeNegativeInteger suclassify `LargeInteger.

Ask Juan?

These are the messages an object knows how to respond to.

Epigram 31

Alan J. Perlis. 1982. Special Feature: Epigrams on programming. SIGPLAN Not. 17, 9 (September 1982), 7–13. https://doi.org/10.1145/947955.1083808

Also transcribed at https://cpsc.yale.edu/epigrams-programming

Epigram 19

Alan J. Perlis. 1982. Special Feature: Epigrams on programming. SIGPLAN Not. 17, 9 (September 1982), 7–13. https://doi.org/10.1145/947955.1083808

Also transcribed at https://cpsc.yale.edu/epigrams-programming

Alternatives

Using “that”

Tip. In the workspace Ctrl-b (Browse) on the class name will open a Browser on that class:

using “named”

Tip. In the workspace Ctrl-b (Browse) on the class name will open a Browser on the class named so:

Alternatives:

1

Tip. In the workspace Ctrl-b (Browse) on the class name will open a Browser on that class:

Tip. In the workspace Ctrl-b (Browse) on the class name will open a Browser on the class named so:

Number selectors size vs Number allSelectors size

Programmatically you can send #browseClassHierarchy to any object

There are no messages categorized as arithmetic in String but in CharacterSequence, which String subclassifies. Squeak Strings on the other hand, implement arithmetic messages, exactly those mentioned in the solution to the exercise; Note however that String allMethodsInCategory: #arithmetic in both Cuis and Squeak include a seventh method #raisedTo: because #allMethodsInCategory also looks up for inherited methods from superclasses. Yes! you can raise the empty string to the power of n for n ∈ Number and the result is another empty string! WAT :) The fact that we can evaluate '' raisedTo: n without error seems like an unforeseen consequence of #adaptToCollection:andSend: relying on #collect and how the latter works on empty collections.

See this thread in the Squeak-dev mailing list

Gilad Bracha's criticism:

Semi-tangent: source code seems the most obvious thing in the world; but traditional Smalltalk’s have no real syntax above the method level! Classes are defined via the evaluation of reflective expressions, which rely on the reflective API. This is very problematic: the API often varies from one implementation to another. By the way, this is one of the ways Newspeak differs from almost every Smalltalk (the late, great Resilient being the only exception I can recall). Newspeak has a true syntax. Furthermore, because Newspeak module declarations are fully parametric in all their external dependencies, they can be compiled at any time in any order - unlike code in most languages (say Java packages) where there are numerous constraints on compilation order (e.g., imports must be defined).

See the full blog post An Image Problem.

The original reads kind of funny. Besides that, #shuffled is a message, not a collection. This paragraph could be rewritten as follows:

Similarly as with #shuffled, all collections know how to answer #sorted with a sorted copy of themselves.

smalltalk (1 to: 4) inject: 0 into: [:sum :n | 1/n squared + sum]

smalltalk 'Hello' at: 1 put: $B; at: 5 put: $e; yourself

Use a Cascade to send several messages to the same receiver. Separate the messages with a semicolon. Put each message on its own line and indent one tab. Only use Cascades for messages with zero or one argument.

—Kent Beck, Smalltalk Best Practice Patterns

In the Spacewar! code snippet below, the parentheses aren't necessary but clarify that the addition happens first:

Proposed change:

When you are not using the base image...

680 classes and 135025 instances on plain Cuis image version 6090. 1356 classes and 518158 instances on my current Cuis Univesity custom image 2023-11-27

TODO inquire about ProtoObject. See post by Christoph Tiede entitled [Bug & design issue] Messages understood or not understood by ProtoObject on squeak-dev

However, the crucial question is: What special messages should an instance of ProtoObject understand? On the one hand, the idea of ProtoObjects is to work as total proxies with a maximum amount of forwarding potential, which implies a minimum number of methods. On the other hand, certain aspects such as accessing instvars or executing messages are really identity-related. Looking forward to your comments :-)

http://lists.squeakfoundation.org/pipermail/squeak-dev/1998-October/017019.html

Also the whole thread named prototypes vs classes ex Sun's HotSpot is worth a read.

Lyle Bickley explains the PDP-1 (and we play the original Spacewar! at Curious Mark YouTube channel

From the description:

Lyle Bickley, of the PDP-1 restoration team, gives us a tour of this amazing, early scientific interactive computer at the Computer History Museum. The first machine built by DEC in 1959, it features a superb graphics screen. DEC gave one to MIT, and some very bright students went wild. Gems such as Spacewar!, Snowflake, 4-voice music programs were all developed by moonlighting MIT students, unencumbered by its measly 12kW memory and pokey 100,000 instructions per second. Along with much more serious debugging and programming languages of course. You can come and see the real machine for yourself at the Computer History Museum in Mountain View, California: http://www.computerhistory.org/

Also, Norbert Landsteiner made this incredible simulation of the PDP-1 that can run the original Spacewar! and Minkytron code in your browser: https://www.masswerk.at/spacewar/ https://www.masswerk.at/minskytron/ He also made a gate exact replica with Verilog code on github: https://www.youtube.com/watch?v=iymD9eysqXo

<details> <summary>Spoiler warning</summary> ```javascript (1 to: 4) inject: 0 into: [:sum :n| sum + 1/n] ``` </details>

The downloads are hosted at GitHub releases page for Cuis University https://github.com/Cuis-University/Cuis-University/releases

Alan J. Perlis. 1982. Special Feature: Epigrams on programming. SIGPLAN Not. 17, 9 (September 1982), 7–13. https://doi.org/10.1145/947955.1083808

Also transcribed at https://cpsc.yale.edu/epigrams-programming

Aplique (formal) o Aplica (imperativo) Misma idea que “mantén”.

See https://github.com/Cuis-Smalltalk/Learning-Cuis#learning-cuis for a chart comparing Cuis to other current Smalltalk distributions.

Unless there is a need to save space, write full names and maybe inlcude hyperlinks.

Why not include hyperlinks?

Ask. This doesn't need to be a footnote in HTML; maybe it is this way because of a texinfo limitation regarding conditional compiling, I. e. HTML (which doesn't need this as a footnote) vs PDF (which needs it but only when a producing a document to be printed).

Cesare Pavese, Il mestiere di vivere. Diario 1935-1950 quoted in, A Personal Computer for Children of All Ages, Kay 1972

Interview by Lars Kongshem but also says this in many recorded talks

It is fair to say that the original Xerox team developed Smalltalk continuosly from 1971 to 1980.

There were also Smalltalk-74 and Smalltalk-78 also known as the NoteTaker Smalltalk, see https://smalltalkzoo.thechm.org/HOPL-St78.html

Cuis University differs from Cuis in that it disables the original left arrow assignment ← and return ↑ glyphs by default, preferring the ANSI Smalltalk syntax, namely := and ^. In order to revert and display the arrow glyphs evaluate Smalltalk Preferences name: #showAssignmentAsLeftArrow category: #programming value: true The two keystrokes := will be shown as ←. Note that typing the underscore character will still show a ← regardless of the setting.

This refers to the new blank wiki, not to the downloaded version of Grok TiddlyWiki.

Gilad

Note the typo. Warnier/Orr diagrams

Program Design Language

Precursor to UML

First crewed landing on the moon.

The draft for the first edition is also publicly available.