Lambda World 2018 - What FP can learn from Smalltalk by Aditya Siram

If you're tired of hearing about the virtues of Smalltalk (like I was at one point) and ask "if it is so good, why isn't it popular?", then watch @deech's talk (Aditya Siram) - "What FP can learn from SmallTalk" - [this video] I think it is the most accessible explanation of the marvel of Smalltalk, for those who were not lucky to work with it during the late 80-90s. Also I think Ruby is the mainstream language that is closest to Smalltalk today, with the idea that everything is an object and late-binding as much as possible. One thing I can't help point out is that Smalltalk / Alan Kay's vision of interconnected objects forming a recursive computing system is not the only "true" vision of OO out there. From Simula thru C++ and then Java and C# also are object-oriented (or class-oriented for those who care about the distinction), but they are statically typed. It is also OO because OO is a word, not a mathematical definition, and when people talk about OO, there is enough similarity between all these variations that we consider all of them to be in the same camp. Plus with the growing move towards strict static typing even in interpreted languages, which I think is driven by actual industry needs and programmer preferences than external marketing, it is becoming a disservice to think of statically typed OO languages as being somehow inferior to the true ideal of object-oriented programming.

Signed up just to say that I've also really, really wanted such a tool since forever. While for example the Jetbrains IntelliJ family of editors has the automatic "inline function" refactoring, they do it by permanently modifying the source code, which is not quite what we want. Like you say, it should be transient! So I recently made a quick&dirty interactive mock-up of how such an editor feature could look. The mockup is just a web page with javascript and html canvas, so it's easy to try here: [link] (Not mobile friendly, best seen on desktop) There are 2 different ways to show the inlining. You can choose between them if you click the cogwheel icon. Then I learned that the Smalltalk editor Pharo already has a similar feature, demonstrated at [this video] I wish other editors would steal this idea. Microsoft, are you listening? My mock-up also shows an idea to improve code folding. When folding / collapsing a large block of code, the editor could show a quick summary of the block. The summary could be similar to a function signature, with arguments and return values.

Not so much .NET/Java but Structured Programming (1972 Edsger W. Dijkstra, Ole-Johan Dahl, and Tony Hoare) has prompted the gradual backlash against switches. ( [link] , re: Duff's Device). Senior developers should watch the whole thing to understand how block scope and functions and classes relate. Modern development has drifted toward lots of small functions (which causes a mess because modern IDEs dont have supporting features like this: [this video] , re: gtoolkit). A switch requires you to look inside and reason about the internals of a function to understand how it will behave before exiting, as the compiler. This doesn't matter so much if you dont care about early exits (no branch prediction, etc). Either way, it's extra cognitive overhead and error prone for a small improvement in readbaility. It's the line where programming becomes tricky programming. As a thought experiment, imagine there is ANOTHER keyword that acts like an if/else (or switch with mandatory breaks). If A. it's terse, B. it's structured, C. it's readable, would that be better? We primarily use switch because it's easy to read (versus a ton of if {}/else {}), as it gives us almost-block scoping without having to define another indirection/function. Python has this switch equivalent in match/case, but you have to use Python to get it. Switch use is a syntax problem. Lots of software is colored by bad syntax and language design^. ^ I think most people realize that type hierarchies are a brittle/limited form