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Turing machines have mutable state. The lambda calculus does not. Yet any algorithm which can be expressed by one can also be expressed by the other. We have pr

Turing machines have mutable state. The lambda calculus does not. Yet any algorithm which can be expressed by one can also be expressed by the other. We have proof that state is merely an implementation detail, which happens to be widespread in today's hardware because we figured out how to implement it at scale. Programmers need to understand the difference between the abstract algorithm they're trying to express and the representation they've chosen (and the ones they didn't) inside the computers they're using, just as astronomers need to distinguish between the stars they study and the measurements coming out of the various telescopes they can choose.

guard-of-terra 14y ago
State is an implementation detail to today's hardware And yesterday's hadware And the day before that And pretty long time, frankly - do you see a pattern here? And it does have its deep reasons. Programming is not about algorithms. It's about making inanimate matter behave. CS might be about algorithms, but CS is not programming.
- spacemanaki 14y ago
  Your hard-line stance is a little bit too far IMHO. That inanimate matter programming is all about manipulating also has no notion of objects or object orientation... or (for the most part) methods, fields, functions, procedures, arrays, modules, encapsulation, interfaces, garbage collection, databases ... and so on and so on. All that abstraction exists to make programming easier for humans to grok, and for teams to deliver some "useful work". To borrow from Robin Milner, who worked on ML: "Types are the leaven of computer programming; they make it digestible." All that abstraction makes programming more digestible, or more palatable. Functional programming is just some more abstraction to make it more digestible. To say that it's a redefinition of programming is just a distraction, since programming has already been redefined. Also, you're right that CS isn't programming, and viewed in a certain light one could argue CS is basically just a branch of math. But on the other hand, programming without CS really wouldn't be that useful. It's just not a helpful distinction to make in this way.
  - guard-of-terra 14y ago
    I would argue that objects, methods, fields, modules, encapsulation, interfaces, garbage collection, databases are not the basics of programming either. Good things to have, but are not basics of programming. So, teach/learn them later in the cycle. Basics of programming are variables, branches, arrays, loops and simple I/O. You can go a long way with these. And you can explain those to 6 yr old child.
    - kamaal 14y ago
      They go a long way for kids. The inventors of C++, Java, Perl, Python, Erlang are trying to solve problems basic to many other domains. So it depends on what you define as basic. What you seem to define are pre requisite to start learning basics.
    - spacemanaki 14y ago
      If we were talking about teaching programming to kids, I actually agree with you. It wasn't clear from the top-level comment that started this thread if that's what we were talking about though. I thought that we were talking about intro to CS for freshmen in college. That's where I think it might be valuable to start with functional programming. Note: might -- I really don't know.
      - guard-of-terra 14y ago
        "People should be required to learn the basics of programming first. They should start with immutable data objects" We weren't talking about freshmen in college. And talking about freshmen in college is not so interesting because they agreed to listen to bullshit (information of questionable utility) by joining college. It's much more interesting to talk about kids or adults because they have the choice.
    - nessus42 14y ago
      > And you can explain those to 6 yr old child. The most popular programming language for teaching children is Logo, a FUNCTIONAL programming language!

guard-of-terra 14y ago

State is an implementation detail to today's hardware And yesterday's hadware And the day before that And pretty long time, frankly - do you see a pattern here? And it does have its deep reasons. Programming is not about algorithms. It's about making inanimate matter behave. CS might be about algorithms, but CS is not programming.

spacemanaki 14y ago
Your hard-line stance is a little bit too far IMHO. That inanimate matter programming is all about manipulating also has no notion of objects or object orientation... or (for the most part) methods, fields, functions, procedures, arrays, modules, encapsulation, interfaces, garbage collection, databases ... and so on and so on. All that abstraction exists to make programming easier for humans to grok, and for teams to deliver some "useful work". To borrow from Robin Milner, who worked on ML: "Types are the leaven of computer programming; they make it digestible." All that abstraction makes programming more digestible, or more palatable. Functional programming is just some more abstraction to make it more digestible. To say that it's a redefinition of programming is just a distraction, since programming has already been redefined. Also, you're right that CS isn't programming, and viewed in a certain light one could argue CS is basically just a branch of math. But on the other hand, programming without CS really wouldn't be that useful. It's just not a helpful distinction to make in this way.
- guard-of-terra 14y ago
  I would argue that objects, methods, fields, modules, encapsulation, interfaces, garbage collection, databases are not the basics of programming either. Good things to have, but are not basics of programming. So, teach/learn them later in the cycle. Basics of programming are variables, branches, arrays, loops and simple I/O. You can go a long way with these. And you can explain those to 6 yr old child.
  - kamaal 14y ago
    They go a long way for kids. The inventors of C++, Java, Perl, Python, Erlang are trying to solve problems basic to many other domains. So it depends on what you define as basic. What you seem to define are pre requisite to start learning basics.
  - spacemanaki 14y ago
    If we were talking about teaching programming to kids, I actually agree with you. It wasn't clear from the top-level comment that started this thread if that's what we were talking about though. I thought that we were talking about intro to CS for freshmen in college. That's where I think it might be valuable to start with functional programming. Note: might -- I really don't know.
    - guard-of-terra 14y ago
      "People should be required to learn the basics of programming first. They should start with immutable data objects" We weren't talking about freshmen in college. And talking about freshmen in college is not so interesting because they agreed to listen to bullshit (information of questionable utility) by joining college. It's much more interesting to talk about kids or adults because they have the choice.
  - nessus42 14y ago
    > And you can explain those to 6 yr old child. The most popular programming language for teaching children is Logo, a FUNCTIONAL programming language!