5 ms·

Every time I see rust news, I feel the urge to learn this language. But, thankfully, someone posts some random snippet. :-) Java is a beautiful language compare

by tychuz 10y ago

Every time I see rust news, I feel the urge to learn this language. But, thankfully, someone posts some random snippet. :-) Java is a beautiful language compared to this.

Sacho 10y ago
My only complaint is the mix between snake_case and PascalCase. I tried removing it(in favor of snake_case, but you could probably get a similar result if going full PascalCase), and it looks much better(no guarantee it has the same semantics, I've never worked with rust): fn handle_message(&mut self, find_node_query: messages::find_node_query) { let origin = node::udp_node::deserialize(find_node_query.get_origin()); let target = address::from_str(find_node_query.get_target()); { // Borrow self.routing_table first time let nodes: vec<&box<node::node>> = self.routing_table.nearest_to(&target); let response = message::response( self.transaction_ids.generate(), response::find_node(&self.self_node, nodes) ); origin.send(response.serialize()); } // Done borrowing self.routing_table here // Borrow self.routing_table again self.routing_table.insert(origin); }
- pcwalton 10y ago
  Rust used to work that way, but it was changed primarily to visually distinguish between enumerated variant names and variable bindings in patterns. e.g. match foo { none => ... } and match foo { non => ... } having completely different interpretations was confusing.
- kibwen 10y ago
  It sure does look more like C that way (if that's something you're into), but that also makes it harder to scan for types at a glance.
dschiptsov 10y ago
Exactly. There are few fundamental principles which have been neglected in order to provide way too many features (a kitchen sinc syndrome). For example, "do not create unecessary entities" maxim, which, it seems, is central for good language design (ML, Scheme, Haskell, Smalltalk, Erlang, Golang are small languages, the first three are even standardized). As long as we violate this genetal rule we end up in a mess like CL, C++, and of course Java as a peak of absurdity). The meme that "implementation languages must be feature rich" does not hold beyond certain limits, and even Rust designers have realized that there must be certain restrictions. In fact, C - the oldest and most common implementation language is still alive and well (despite all the mess other people made of it since it left Bell Labs). The best illustration I know is refusal of the Golang designers to complicate (to ruin the balance of simplicity and elegance with expressiveness, which is the most difficult to attain - every poet or artist will tell you that - to create an unbalanced pile of features is way easier) the language by adding generics in the language and runtime. For them interfaces (duck-typing) is good-enough). "Explicit is better than implicit" is also a naively wrong maxim. Verbosity is bad. Period. Every good writer I know is non-verbose. Meaning behind words is what makes a good literature, not long words or elaborate passages half page long (ironically, common men think exactly opposite is true). Convention over configuration (evolved defaults instead of explicitly spelling every single rule over and over again) is the same notion from a different perspective. Here comes Scheme - the greatest mostly-functional small language with balanced defaults, cohetent semantics (almost like in math), and unmatched expressiveness with almost no syntax at all (expressive power comes from coherent defaults that everything is an expression, everything (including lambdas) is a first-class value referenced by symbol, lexical scooping, very few standard special forms and the ability to create new ones.) as an good example. Smalltalk and Erlang are another ones for the emphasis on message passing and, in case of Erlang - pure functionality and isolation - the way vastly complex biological systems has been implemented by evolution. So, those who have seen highly refined languages like Haskell or Scheme or Smalltalk would never be fooled by "features". The meme that "each project must first agree on which subset of C++ it would restrict itself to" is another good illustration. Rust, like Java, is already suffering from this kitchen sink syndrome, so the comment above is legitimate. BTW, it seems that many of features should go from the language to sanitizers and checkers, like it is with clang tooling.
- pcwalton 10y ago
  Do you have specific examples of Rust features you claim are unnecessary? Rust would not work at all with the borrow check as a separate tool, by the way. It would be comically easy to write broken code.
- kibwen 10y ago
  Rust is emphatically not a kitchen sink language. If you believe otherwise, please explain what features you would remove without compromising safety or the notion of zero-cost abstractions.
  - dschiptsov 10y ago
    I don't believe in safety and zero costs. These are mere catchy memes. I could only repeat my question: How Common Lisp or even more pragmatic Golang are less safe? I am not asking about Haskell or Erlang.) Compile time error for trying to use an old binding/reference? Is this memory safety?
    - pcwalton 10y ago
      Go is less safe due to the "Off to the Races" problem, but there's a legitimate debate as to whether that safety loss matters in practice. Common Lisp and Golang use GC, which exacts a performance cost in some scenarios. Go also has highly dynamic semantics (e.g. with defer) which have unavoidable performance overhead, especially in an AOT compilation setting.
    - nercury 10y ago
      The engineering decisions are not based on beliefs. They are usually trade-offs. Safety in Rust has a very specific meaning clearly outlined in the official book. There are users who prefer it for certain tasks. The answer to your last question is also in the book.
      - dschiptsov 10y ago
        Why not state it here in a few simple sentences, like for a 5 year old? Clarity is usually an evidence for deep understanding. I hope I will be able to get it.
baq 10y ago
Java is also a completely different language. Each tool has a different purpose.
jeffdavis 10y ago
Can you please post an equivalent Java program for comparison?

by tychuz 10y ago

Every time I see rust news, I feel the urge to learn this language. But, thankfully, someone posts some random snippet. :-) Java is a beautiful language compared to this.

Sacho 10y ago

My only complaint is the mix between snake_case and PascalCase. I tried removing it(in favor of snake_case, but you could probably get a similar result if going full PascalCase), and it looks much better(no guarantee it has the same semantics, I've never worked with rust): fn handle_message(&mut self, find_node_query: messages::find_node_query) { let origin = node::udp_node::deserialize(find_node_query.get_origin()); let target = address::from_str(find_node_query.get_target()); { // Borrow self.routing_table first time let nodes: vec<&box<node::node>> = self.routing_table.nearest_to(&target); let response = message::response( self.transaction_ids.generate(), response::find_node(&self.self_node, nodes) ); origin.send(response.serialize()); } // Done borrowing self.routing_table here // Borrow self.routing_table again self.routing_table.insert(origin); }

pcwalton 10y ago
Rust used to work that way, but it was changed primarily to visually distinguish between enumerated variant names and variable bindings in patterns. e.g. match foo { none => ... } and match foo { non => ... } having completely different interpretations was confusing.
kibwen 10y ago
It sure does look more like C that way (if that's something you're into), but that also makes it harder to scan for types at a glance.

dschiptsov 10y ago

Exactly. There are few fundamental principles which have been neglected in order to provide way too many features (a kitchen sinc syndrome). For example, "do not create unecessary entities" maxim, which, it seems, is central for good language design (ML, Scheme, Haskell, Smalltalk, Erlang, Golang are small languages, the first three are even standardized). As long as we violate this genetal rule we end up in a mess like CL, C++, and of course Java as a peak of absurdity). The meme that "implementation languages must be feature rich" does not hold beyond certain limits, and even Rust designers have realized that there must be certain restrictions. In fact, C - the oldest and most common implementation language is still alive and well (despite all the mess other people made of it since it left Bell Labs). The best illustration I know is refusal of the Golang designers to complicate (to ruin the balance of simplicity and elegance with expressiveness, which is the most difficult to attain - every poet or artist will tell you that - to create an unbalanced pile of features is way easier) the language by adding generics in the language and runtime. For them interfaces (duck-typing) is good-enough). "Explicit is better than implicit" is also a naively wrong maxim. Verbosity is bad. Period. Every good writer I know is non-verbose. Meaning behind words is what makes a good literature, not long words or elaborate passages half page long (ironically, common men think exactly opposite is true). Convention over configuration (evolved defaults instead of explicitly spelling every single rule over and over again) is the same notion from a different perspective. Here comes Scheme - the greatest mostly-functional small language with balanced defaults, cohetent semantics (almost like in math), and unmatched expressiveness with almost no syntax at all (expressive power comes from coherent defaults that everything is an expression, everything (including lambdas) is a first-class value referenced by symbol, lexical scooping, very few standard special forms and the ability to create new ones.) as an good example. Smalltalk and Erlang are another ones for the emphasis on message passing and, in case of Erlang - pure functionality and isolation - the way vastly complex biological systems has been implemented by evolution. So, those who have seen highly refined languages like Haskell or Scheme or Smalltalk would never be fooled by "features". The meme that "each project must first agree on which subset of C++ it would restrict itself to" is another good illustration. Rust, like Java, is already suffering from this kitchen sink syndrome, so the comment above is legitimate. BTW, it seems that many of features should go from the language to sanitizers and checkers, like it is with clang tooling.

pcwalton 10y ago
Do you have specific examples of Rust features you claim are unnecessary? Rust would not work at all with the borrow check as a separate tool, by the way. It would be comically easy to write broken code.
kibwen 10y ago
Rust is emphatically not a kitchen sink language. If you believe otherwise, please explain what features you would remove without compromising safety or the notion of zero-cost abstractions.
- dschiptsov 10y ago
  I don't believe in safety and zero costs. These are mere catchy memes. I could only repeat my question: How Common Lisp or even more pragmatic Golang are less safe? I am not asking about Haskell or Erlang.) Compile time error for trying to use an old binding/reference? Is this memory safety?
  - pcwalton 10y ago
    Go is less safe due to the "Off to the Races" problem, but there's a legitimate debate as to whether that safety loss matters in practice. Common Lisp and Golang use GC, which exacts a performance cost in some scenarios. Go also has highly dynamic semantics (e.g. with defer) which have unavoidable performance overhead, especially in an AOT compilation setting.
  - nercury 10y ago
    The engineering decisions are not based on beliefs. They are usually trade-offs. Safety in Rust has a very specific meaning clearly outlined in the official book. There are users who prefer it for certain tasks. The answer to your last question is also in the book.
    - dschiptsov 10y ago
      Why not state it here in a few simple sentences, like for a 5 year old? Clarity is usually an evidence for deep understanding. I hope I will be able to get it.

baq 10y ago

Java is also a completely different language. Each tool has a different purpose.

jeffdavis 10y ago

Can you please post an equivalent Java program for comparison?