Exercise to focus on constructors

[bencoman]

Saw this comment from a newcomer on Discord...

Delphi did have constructors more similar to Smalltalk than Java. Didn't have a silly special "new" keyword.. it was a method on the class itself.

I see a few people respond with "just use a class-side method", but I think newcomers often miss the distinction and such comments fly by without sticking. It might be good to have an exercise focused specifically on analogies to "constructors" as people understand them in other languages.

Could it be said that the "instance creation" class-side protocol is equivalent to "constructors" ?

Possible reference cases:

Rectangle
Delay
Month
Color

[bencoman]

Other interesting constructors...

constructors := Object allSubclasses flatCollect: [ :c | c class allMethods select: [ :m | m protocol = 'instance creation' ] ].
distribution := (constructors collect: [ :m | m selector ]) asBag.
unique := distribution valuesAndCounts keysAndValuesRemove: [ :k :v | v > 1 or: [ k implementors size > 1 ] ].
uniqueConstructors := (unique keys flatCollect: [ :symbol | symbol implementors ] ) sorted.

[samWson]

Could it be said that the "instance creation" class-side protocol is equivalent to "constructors" ?

Short answer I'd say yes. I treat methods in this protocol as a way of getting a fully initialized object in a convenient way. In my own projects I use class side initializing methods as a public interface and the proper way to get an instance of that class instead of using #new and setting up all the instance variables yourself.