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>I never understood this obsession with lambda calculus or ycombinator. It's a very foundational thing--at the foundation of theoretical computer science and a

>I never understood this obsession with lambda calculus or ycombinator. It's a very foundational thing--at the foundation of theoretical computer science and a lot of programming languages. Understanding it pays a lot of dividends over your life--even if you don't use it directly. By now it's a mandatory course at many CS universities anyway--so that tells you how foundational it is. >If most of the computers have an instruction set that is rich and has support for loops and types and other things, what use is it to waste your time to understand this? Because lambda calculus is much simpler than that and still can do everything. As an engineer you strive for simplicity, right? Lambda calculus is so simple, you can learn it (all of it!) in a week. You will be able to compute everything that can be computed--WITHOUT having jumps, loops, types, instruction sets, numbers, booleans, lists and so on at the foundation. The foundation is function definition and function calls. The argument is a function, and so is the result. It's functions all the way down. You might think it's functions and numbers? Nope. Booleans? Nope. Lists? Nope. Loops? Nope. It's JUST functions at the foundation. This makes it much easier to build programming languages and/or analyze programs because you have only very few primitives that the end user (programmer) can still use to build whatever they want! Get this, you can remove almost everything and still it works perfectly. The end result will look mostly like any other source code you are used to. The most interesting thing about the Y combinator is that it's NOT A PRIMITIVE. That is so weird. You have a language that has recursion nowhere in the primitives, and it's able to recurse.

hnfong 4y ago
> Because lambda calculus is much simpler than that and still can do everything. As an engineer you strive for simplicity, right? Brainf_ck is just as simple and it's also Turing Complete. You can't really say one way of expressing computation is more foundational than the other since they're all computationally equivalent. BF might not be as elegant as lambda calculus, but if your claim is true I don't see why it's not included as an alternative of the CS curriculum. The real reason, IMHO, is that computer science historically evolved from disciplines that studied logic systems, and was a system that was proposed by Alonzo Church. There's a lot of worship for formal systems within the CS community, and in a self-referential way that makes it important because everyone else worth their salt would know this stuff.

hnfong 4y ago

> Because lambda calculus is much simpler than that and still can do everything. As an engineer you strive for simplicity, right? Brainf_ck is just as simple and it's also Turing Complete. You can't really say one way of expressing computation is more foundational than the other since they're all computationally equivalent. BF might not be as elegant as lambda calculus, but if your claim is true I don't see why it's not included as an alternative of the CS curriculum. The real reason, IMHO, is that computer science historically evolved from disciplines that studied logic systems, and was a system that was proposed by Alonzo Church. There's a lot of worship for formal systems within the CS community, and in a self-referential way that makes it important because everyone else worth their salt would know this stuff.