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I always remember SPJ’s chart in a short jokey video “Haskell is useless” https://youtu.be/iSmkqocn0oQ https://youtu.be/iSmkqocn0oQ Really made me see things c

I always remember SPJ’s chart in a short jokey video “Haskell is useless” https://youtu.be/iSmkqocn0oQ https://youtu.be/iSmkqocn0oQ Really made me see things clearer.

eklavya 5y ago
It’s funny in my mind that I laughed at his joke about “the computer would just produce heat” and somehow the whole of cryptocurrency is literally doing just that.
Mikeb85 5y ago
Good video, never seen it before. Thanks! Also love the fact he doesn't take himself or programming things too seriously (Haskell in useless category is great).
ksec 5y ago
I really like his chart about usefulness and Unsafe programming. And that was in 2011! We have seen in the past 10 years how programming moving in the direction he was pointing at.
graffitici 5y ago
I guess Rust is a language that went the move to Safe and Useful, following the top arrow?
- amelius 5y ago
  It lacks a GC however, which Haskell has for a reason.
- WJW 5y ago
  Rust prevents a few types of unsafety, mostly relating to memory and concurrency. There are many more on which Rust does not do particularly well though. Specifically, Rust allows arbitrary side effects from basically any part of the code. You can always write to stdout or a logfile, or open up new sockets, or delete files from the filesystem and there will be nothing in the type signature to even warn you about this.
  - discreteevent 5y ago
    >write to stdout or a logfile, or open up new sockets, or delete files from the filesystem Do those things come under the category of unsafe? Why would we be programming if it weren't to do those kinds of things? If I buy a shovel, at some point I'll probably want to dig a hole with it.
    - colonwqbang 5y ago
      The point is not that you shouldn't do these things. The point is that Rust does not provide any tools to help you do it safely. Mutation is also a necessary thing in programming, which can be unsafe if done incorrectly. Rust has many built in rules for keeping mutation safe and requires labelling functions that mutate. For side effects, there is not much of a safety net in rust.
    - TheDong 5y ago
      Absolutely. If you watch the youtube video linked in this thread, SPJ makes that very comment, that a program with zero effects is useless. However, the goal of haskell (and indeed any language trying to be safe in the way SPJ means) is to be able to have most code be safe/effect-free, and then to have effects be very carefully controlled and limited in their use. Things like the IO monad mean many parts of haskell code can't do IO in fact. We obviously do want some sort of effect in the end, but the idea is it's safer to contain those effects in very limited places, and not allow effects to happen literally anywhere at any time. Note, unsafe in the SPJ video was specifically about effects, while "unsafe" in rust terminology is mostly about memory safety, so those two terms really aren't the same word, and to be honest that can make communication less clear. I don't know what "category of unsafe" meant in your comment really.
    - pyrale 5y ago
      The basic idea isn't that you want to avoid such activities, but that you want to know which functions do it, so that it is easier to reason about your program.
    - WJW 5y ago
      If you'd watched the video from the grandparent comment, you'd have seen that those kind of uncontrolled side effects are exactly what Simon Peyton Jones was talking about in the video when talking about "safe" versus "unsafe" languages. But in any case, yes those things I mentioned can fall under the category of "unsafe". In the category of memory safety, you want to be sure (with compiler guarantees!) that no thread will secretly free some allocated memory while you are still using it. This is something the borrow checker can give you in rust. There are no builtin guarantees in Rust that this fancy new library you imported won't do `DROP TABLE users`, or open a socket to https://haxorz.com https://haxorz.com and pass on all the environment variables. There are other languages in which you can be sure that a function cannot open any sockets unless it specifically has "can open sockets" encoded in its type.
- kzrdude 5y ago
  I think SPJ is using a slightly different definition of safe than Rust does! But Rust should definitely be a bit up his safeness scale, but not all the way, doesn't fully control all effects.

I always remember SPJ’s chart in a short jokey video “Haskell is useless” https://youtu.be/iSmkqocn0oQ https://youtu.be/iSmkqocn0oQ Really made me see things clearer.

eklavya 5y ago

It’s funny in my mind that I laughed at his joke about “the computer would just produce heat” and somehow the whole of cryptocurrency is literally doing just that.

Mikeb85 5y ago

Good video, never seen it before. Thanks! Also love the fact he doesn't take himself or programming things too seriously (Haskell in useless category is great).

ksec 5y ago

I really like his chart about usefulness and Unsafe programming. And that was in 2011! We have seen in the past 10 years how programming moving in the direction he was pointing at.

graffitici 5y ago

I guess Rust is a language that went the move to Safe and Useful, following the top arrow?

amelius 5y ago
It lacks a GC however, which Haskell has for a reason.
WJW 5y ago
Rust prevents a few types of unsafety, mostly relating to memory and concurrency. There are many more on which Rust does not do particularly well though. Specifically, Rust allows arbitrary side effects from basically any part of the code. You can always write to stdout or a logfile, or open up new sockets, or delete files from the filesystem and there will be nothing in the type signature to even warn you about this.
- discreteevent 5y ago
  >write to stdout or a logfile, or open up new sockets, or delete files from the filesystem Do those things come under the category of unsafe? Why would we be programming if it weren't to do those kinds of things? If I buy a shovel, at some point I'll probably want to dig a hole with it.
  - colonwqbang 5y ago
    The point is not that you shouldn't do these things. The point is that Rust does not provide any tools to help you do it safely. Mutation is also a necessary thing in programming, which can be unsafe if done incorrectly. Rust has many built in rules for keeping mutation safe and requires labelling functions that mutate. For side effects, there is not much of a safety net in rust.
  - TheDong 5y ago
    Absolutely. If you watch the youtube video linked in this thread, SPJ makes that very comment, that a program with zero effects is useless. However, the goal of haskell (and indeed any language trying to be safe in the way SPJ means) is to be able to have most code be safe/effect-free, and then to have effects be very carefully controlled and limited in their use. Things like the IO monad mean many parts of haskell code can't do IO in fact. We obviously do want some sort of effect in the end, but the idea is it's safer to contain those effects in very limited places, and not allow effects to happen literally anywhere at any time. Note, unsafe in the SPJ video was specifically about effects, while "unsafe" in rust terminology is mostly about memory safety, so those two terms really aren't the same word, and to be honest that can make communication less clear. I don't know what "category of unsafe" meant in your comment really.
  - pyrale 5y ago
    The basic idea isn't that you want to avoid such activities, but that you want to know which functions do it, so that it is easier to reason about your program.
  - WJW 5y ago
    If you'd watched the video from the grandparent comment, you'd have seen that those kind of uncontrolled side effects are exactly what Simon Peyton Jones was talking about in the video when talking about "safe" versus "unsafe" languages. But in any case, yes those things I mentioned can fall under the category of "unsafe". In the category of memory safety, you want to be sure (with compiler guarantees!) that no thread will secretly free some allocated memory while you are still using it. This is something the borrow checker can give you in rust. There are no builtin guarantees in Rust that this fancy new library you imported won't do `DROP TABLE users`, or open a socket to https://haxorz.com https://haxorz.com and pass on all the environment variables. There are other languages in which you can be sure that a function cannot open any sockets unless it specifically has "can open sockets" encoded in its type.
kzrdude 5y ago
I think SPJ is using a slightly different definition of safe than Rust does! But Rust should definitely be a bit up his safeness scale, but not all the way, doesn't fully control all effects.