I was going through an introduction to Smalltalk. In C++, the functions declared inside a class can be called by objects of that class, and similarly in Smalltalk a keyword, termed as message, is w...

Like in other programming language, is there a way of running linux shell command in Pharo smalltalk or a simple script ? I would like to have my Pharo image running a script that should be able to...

I cannot understand this piece of Smalltalk code: [(line := self upTo: Character cr) size = 0] whileTrue. Can anybody help explain it?

There might exist dialect specific ways, or maybe a general one. I have two dictionaries, let's say: a := {'a' -> 1} asDictionary. b := {'b' -> 2} asDictionary. Now I want to get c as the un...

Preamble This is about improving message send efficiency in a JIT compiler. Despite referring to Smalltalk, this question applies to most dynamic JIT-compiled languages. Problem Given a message...

Is there a built-in function in smalltalk that takes as input two timespans, and checks whether they intersect? As an example: the two timespans 2018/01/01-2018/01/05 and 2018/01/03-2018/01/10 do i...

I am trying to extend Pharo with promises/futures. I came across this website http://onsmalltalk.com/smalltalk-concurrency-playing-with-futures. It implements futures in Smalltalk. However, when I ...

Let's suppose that I have an object, x, which can accept any one of the selectors, s1, s2, ..., sn. Let's further suppose that the result of any one of these selectors operating on the object is an...

In Squeak, is it possible for a GUI program to have multiple windows? For example, if I am making a painting application, is it possible for the "paint palette" and the "canvas"...

I am learning a little assembly and for my next project I would like to learn how to make an incremental assembler. By "incremental assembler" I mean an assembler that accepts new code wh...

I stumbled upon Smalltalk and further downloaded Pharo, because it was recommended. My first impression is very positive. I wanted to port some simple programs I have written in C++ (my main langua...

I found a (possibly outdated and incorrect) blog post from 2004 which claimed that it was impossible to run Smalltalk scripts from the command line. Has anything changed since then, and is it possi...

In Smalltalk, is there a way to search for all methods available (of any object), say, that contain the word convert (case insensitive search), and also contain the word string? (the method name, n...

I just started learning Smalltalk at uni. I would like to know the difference between the messages & and and: (just like | and or:)

I have a string an I would like to be able to take a substring from the middle of it. For example for the string 'abcdefg' I want to get 'cde' (but the exact start and stop could be arbitrary). I h...

I am learning Pharo and I want to understand if classes/objects like nil which belongs to UndifnedObject class have only 1 instance and act like a singleton, or is a new instance made every time we...

The implementation of Integer>>#factorial in Pharo is: factorial "Answer the factorial of the receiver." self = 0 ifTrue: [^ 1]. self > 0 ifTrue: [^ self * (self - 1) factorial]. sel...

Suppose you have a class Foo, and that you want to be able to multiply a Foo by a Number to get another Foo, using ‘@@‘ as the multiplication sign. Since multiplication is commutative, it would be ...

How to convert information from one object's format to another? In Smalltalk best practice patterns by Kent Beck, he discouraged "adding all the possible protocol needed to every object they m...

I'm currently puzzling over the response provided by the class method Float>>asFraction and its various forms. Here are a few examples: GNU Smalltalk 0.001 asFraction 1/1000 0.001 asExactFrac...

What is the exact meaning of these characters ←, ≡, ¬, ≠, ⌾, and ∢ and how are used in Smalltalk-80? consider the following expressions: (taken from the smalltalk-80 source code) ^self class ≡ x ≡...

I was just wondering if there is a way to work with multiple screens in Pharo or Squeak. I am just switching from VisualWorks to Pharo and am really missing this feature. I am used to having my wor...

I wanted to mess around with OSSubprocess (written by Mariano Martinez Peck) from my Pharo 6.1 on my CentOS 7.4. I searched within the Pharo Project Catalog and tried to install it. I got an erro...

In smalltalk, everything happens by sending messages to receiver objects. Its syntax usually follows the format receiver message, in which receiver is an object that the message is sent to. Now I c...

What is a Smalltalk "image"? Is it like serializing a Smalltalk run-time?