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Why the heck would I run such a long expose and troll you and be mistaken at the same time.
>How does this Haskell program write to stdout if it doesn't mutate memory?
Let's not be stupid here. Every program on the face of the earth must mutate memory because that's how computers work. Assembly instructions mutate things. We're not even talking about that. We're talking about application level programming where we only deal with primitives that the application programmer is aware about. I am saying that at the application level within the category of Hask nothing is mutated.
In your example tell me what haskell primitive.... What variable or data was mutated within haskell? That is what I'm referring to.
Try to implement IO or ST in another lang using only purely functional primitives. Use your algebra to make it work. You'll find it's impossible. What this means is that imperative primitives must exist for any programming to work.
>Then it doesn't work. Every Haskell program does nothing, because mutation of program state does not occur.
Obviously I'm operating on a certain layer of abstraction here. In X = 6, X is obviously immutable in haskell. A runtime is obviously executing your haskell program and mutating the console but your haskell code itself is pure. But you know this. It's quite obvious you're the one that's trolling.
The stdout buffer.
Just because mutation isn't explicit doesn't mean it isn't there. Programming languages are not syntax devoid of meaning: they have semantics. What happens at runtime is part of what a programming language does. (Arguably, that is the most important part of what they do.)
>What this means is that imperative primitives must exist for any programming to work.
That's completely untrue. Imperative languages can be implemented as a subset of functional ones[1] and vice versa. Again, they're just different models. No language can do anything if it isn't implemented in a machine. A machine isn't "imperative"[2], it's a pile of atoms that do what atoms do, without paradigm or instruction. You absolutely could implement a pure functional assembly language. The reason nobody has, is because it doesn't matter: any Turing complete language can be used to implement any other language[3].
Try to implement `volatile` in C without using another language. Does that mean C fails to model real hardware? No, because it has `volatile` to get volatile semantics! Just like Haskell has IO to get I/O side-effects. Or ST to get mutation semantics.
> Use your algebra to make it work. You'll find it's impossible.
Don't assert it, Prove it. Show me one computable function that cannot be computed using boolean algebra.
[1] https://www.microsoft.com/en-us/research/wp-content/uploads/... [3] https://en.wikipedia.org/wiki/Lisp_machine [2] https://en.wikipedia.org/wiki/Turing_completeness
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"Biden is not Trump's opponent." (Didn't need to be questioned, but apparently it's also up for debate?)
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Beliefs must have consequences, and as a consequence of their beliefs, they won't be seeing me alive again. It's really the least I can do. I'm not interested in playing a stooge for them to gleefully fling their ignorance at.
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This is just your bias. I never said this. I feel some people worship a paradigm so much that they see everything as an attack. FP is great however it is not a one size fits all solution. There are limitations. This is literally what I said.
>Mathematicians have no trouble modeling change. There are many ways to do so. Some are algebraic, some are not. There is nothing wrong with modelling mutability using immutable structures: that is how you probably think about history, after all.
You can model change with purity but the program in the end actually has to conduct the change without the modelling. The application has to eventually perform real world actions and the purity of your program cannot protect you from potentials pitfalls of imperative style errors/mistakes.
You have a database. The purity of haskell does not remove the necessity of mutating data in that database.
What you can do is segregate dealing with mutation/IO to a framework or external service. This is what haskell does, but you see this is just shifting the problem to somewhere else. Someone somewhere still had to deal with the issue of mutation. Modelling mutation with purity does not eliminate the problem it only moves the problem to another location.
Segregation of mutation/IO into a framework is a good thing. It makes it so that the problem can be solved one time, rather then a problem solved many times. However the main point of my post is to say that "math" or "algebra" is not a one size fits all solution. You cannot model everything this way, moving the problem into a framework does not make the problem disappear. Someone still had to use imperative primitives to deal with the issue. Think about the complexity of a SQL database.
I have no bias for FP. I just don't understand what you're getting at.
>the purity of haskell does not remove the necessity of mutating data in that database.
That's great, because the purity of Haskell does not inhibit mutability. It just constrains it to lie within some mutable context.
>Modelling mutation with purity does not eliminate the problem it only moves the problem to another location.
Location? What is a location? It's like you're saying you can't truly add 3 + 3, because someone still has to add 1s under the hood. It's just a different model of the same problem.
Honestly, it sounds to me like you've never used the language, and your criticisms come off a bit like standing on an aircraft carrier shouting about how iron boats will never float.
I'm speaking in less technical terms. For example in general mathematical equations or axioms represent immutable concepts. In programming, variables mutate and change... very different from what math traditionally represents. Haskell is an attempt to segregate the immutability (the math part) away from the less "mathy" part (the mutations/IO).
Maybe math is too broad of a term. I probably meant to say "algebra" can't model all of programming, or whatever more suitable word that may or may not exist.
Either way, it is unclear what you're actually trying to say. Haskell has methods for modelling change of state through pure objects, but you're talking about that as though it were an inherently flawed or invalid approach, rather than one of many equally valid approaches to modelling state transformations.
Mutations and IO are very critical parts of programming and the two areas where FP breaks down. Even the IO Monad leaks the imperative nature of the program over to the programmer.
The only way pure FP can sort of work is if there are heavy frameworks abstracting IO and mutation away from the programmer. If you're not doing IO or mutating something then your caching framework, database or Haskell runtime is doing it for you. Additionally like I said earlier, Even if your database is handling mutation for you, you still end up embedding mutation commands into the strings of your pure FP function. Updating a database in haskell still necitates the haskell user to place the mutation command in a SQL string.
My point is, that math is not the complete solution to the programming problem. What FP allows the programmer to do is to use the framework to segregate combinatorial logic away from mutation and IO. Your combinators will always be more composeable and modular but your IO and mutation functions will be less modular but they still have to exist.
This is completely untrue. You may not be familiar with the math, but that doesn't mean it doesn't exist. If you can model something well enough to understand it, then you can model it mathematically. There really isn't any domain of knowledge that math is unsuitable for, excepting if you don't know any relevant math to do.
I won't be responding, and they seem to think they're quite the expert in this sort of thing.