[Cuis-dev] The Cuis-Smalltalk Book Exercise 2.3: Count of methods

Ezequiel Birman ebirman77 at gmail.com
Sun Dec 3 06:16:30 PST 2023

To answer myself, 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 with empty collections.

On Fri, 1 Dec 2023 at 21:56, Ezequiel Birman <ebirman77 at gmail.com> wrote:

> The exercise is:
>> How many methods are there in the arithmetic method category of the
>> String class?
> There are no messages categorized as arithmetic in String but in
> CharacterSequence, which String subclassifies. Maybe it was different
> before; Squeak Strings implement arithmetic messages, exactly those
> mentioned in the solution to the exercise:
>> the count of methods in the last right panel is 6: *, +, -, /, // and \\.
> But `String allMethodsInCategory: 'arithmetic'` in both Cuis and Squeak
> evaluates as:
>>  #(#* #+ #- #/ #// #\\ #raisedTo:)
> Seven methods and yes! you can raise the empty string to the power of n
> for n ∈ Number. WAT! The result is another empty string :) Are we able to
> do this because of historical reasons? Strings in Squeak can be added E.g
> `'3' + '4'` is the string '7'.
> Btw, I'm sharing my annotations
> <https://hyp.is/k4BuJpCLEe6_Z59nfniWQQ/cuis-smalltalk.github.io/TheCuisBook/A-brief-introduction-to-the-system-Browser.html>
> via hypothes.is publicly but you'll need to install the Chrome plugin or
> the unofficial Firefox extension
> <https://github.com/diegodlh/unofficial-hypothesis-extension> to see
> them. I've requested to use their proxy so you don't have to, but it might
> take some time. Once you install any of the plugins you'll be able to read
> and write comments. The UI looks like this:
> [image: imagen.png]
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