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by evercast 1703 days ago
When looking at the GoF design patterns, I believe one should also note that they were created not only to solve a bunch of design problems, but also to deal with the limitations of the programming languages back in the day. For example, if you learn about them in the Java context, they make perfect sense as they are well aligned with the language features required to implement them. Try however putting them in Python context and they often result in unnecessary complexity.

You can actually see this in the article. The Python examples are awful (not very idiomatic). This is just Java written in Python, even with non-Pythonic camelCase naming.
1 comments
thedracle 1702 days ago
Python is four years older than Java, and both have been extended a great deal since their inception.

The original Design Patterns book was written with Smalltalk in mind, which was dynamically duck typed, and had functional features (code blocks), among other things that didn't come to Java or Python for almost a decade.

Perhaps some language features are comparable to and negate the need for some design patterns, like Visitor with multiple dispatch which is provided by Julia --- but most creational, and behavioral design patterns are more just techniques that are independent of most languages and language features.

I definitely dislike the flavor of these articles that paint design patterns as a toolkit to piece together to build programs, rather than recognized components of a sound architecture which can help you build and design software that can be more easily reasoned about and extended.

It does lend to people making rube-goldbergesque monstrosities without really thinking about the why behind the way they are doing things.

I do think there are patterns I have recognized while programming in Rust, Ocaml, and a number of other languages, which never have had a description lent to them; and it's nice to see design patterns being talked about again, beyond the hype of the 1990's.

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igouy 1702 days ago
> … written with Smalltalk in mind…

"Since we must eventually implement our designs, a design pattern also provides sample C++ and (sometimes) Smalltalk code to illustrate an implementation."

Chapter 1. Introduction. "Design Patterns: Elements of Reusable Object-Oriented Software"

https://www.google.com/books/edition/_/6oHuKQe3TjQC

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thedracle 1701 days ago
What's your point exactly? Did they have smalltalk in mind or not?
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igouy 1701 days ago
I wouldn't say so:

Two of the authors - Erich Gamma, John Vlissides - clearly had a background in C++.

Ralph Johnson - clearly had a background in Smalltalk.

Richard Helm - not enough information.

They said -- "We chose Smalltalk and C++ for pragmatic reasons: Our day-to-day experience has been in these languages and they are increasingly popular."

They said -- "Our patterns assume Smalltalk/C++-level language features…"

So when the original Design Patterns book was written, which features did C++ have "that didn't come to Java or Python for almost a decade" ?

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thedracle 1692 days ago
Okay... They knew of Smalltalk, and many of the design patterns were around smalltalk features.

And as you pointed out one of the authors had a strong background in smalltalk, and they chose Smalltalk for examples presented in the book.

In other words, they had smalltalk in mind.

It wasn't like smalltalk was some alien language none of the authors had ever heard of, or wasn't the subject of the book in any way.

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igouy 1691 days ago
In their words, they had "Smalltalk and C++" in mind.
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