Experiments with Ruby and Go
jorin.me
jorin.me
- Go speeds up my workflow since the compiler catches many of my errors. When I write Ruby, I'm about 75% confident it will be right first-time. With Go, that's about 95%.
- I ended up thinking about every possible error. With Ruby, edge-cases would often only crop up after a few weeks of running the code in production.
Exactly. In Go you can't just wrap code in a try/catch block and not deal with the fall out. You can ignore errors with _, but you still have to explicitly write out _, so you visually see what you're ignoring.
I think this is Go's simplicity is actually helpful. It feels like boilerplate at first, but there is something to being _forced_ to handle edge cases sooner rather than later.
No, it can't. If this is something you've seen "many times", would you mind providing an example? Show me a program that Ruby tries to execute without having been able to parse it.
if foo.something
foo.instance_eval "SYNTAX ERROR"
end
But perhaps what he meant was not a syntax error, but things like:
if foo.something
foo.something_misspelled = bar
end
And instead of 'try / catch', you have the frustrating 'if err != nil { return nil, nil }'.
io.Copy(out, in)
With Java exceptions, at least, you must explicitly handle an exception in some way. If you don't try/catch it, you have to add the throws declaration to your method. You have to handle that case.
Furthermore, you know exactly what sort of error it is. In Go, you get the silly "error" interface. So it's something. Have fun figuring out how to handle it. It's not like the language encourages you to just return 'errors.New/fmt.Errorf' so there's actually no way short of complicated regex string matches to figure out what error case you're actually handling. You don't get given all possible types of the error, if you try to switch on err == io.EOF or err == io.UnexpectedEOF or so on, how will you know that you got them all? The compiler sure as hell won't tell you.
With exceptions, you typically do have to get them all, you do have to account for all the types (and if you add a new type further down the stack, you'll have to make sure you handled it correctly further up). You can just catch 'Exception' and be in a similar place to Go, but at least Exceptions give you the option to do things more right.
Your point makes utterly no sense to me. Between Go 'errors' and Java 'Exceptions', only exceptions a) Make you actually think about and handle every one of them b) Can give you information about all possible types it may have and c) allow you to elegantly let a parent function handle it without 3 lines of utterly boilerplate code after every single function call.
Sometimes I think that Gophers just want to feel like they're handling errors. so they love 10% of their code being utterly worthless while not actually having any common way to handle specific error types and while managing to make worse error handling then every single other modern language, and then be proud of it.
Correct, and I agree this isn't explicit. I'd actually like to see you _not_ be able to ignore errors like this. But that's just me maybe.
> Your point makes utterly no sense to me.
My point is Go, by it's simplistic nature, more often than not forces you to at least think about the error case, instead of punting it to another part of the code. This is the point of the parent comment which I'm in agreement with.
If you're writing 'if err != nil { return nil, nil}' you're failing on oh so many levels.
Also, Java doesn't make you think about handling exceptions any more than Go does. If we're talking about code, I've seen lots of Java where the programmer figured "oh, I'll let someone else handle these exceptions..."
The reason why errors are better than exceptions is mainly that it is clear, when reading any function, what lines can fail, and what happens if they do. When reading a java function, you have no idea if half the lines in the function throw an exception. You might know the function as a whole can throw, but you don't know where execution might suddenly stop inside the function. You have to lean on the IDE to look at the definitions of all the functions this function calls, to see if they can throw, which is not something you can do when looking on github, or in a code review, or in an email notification for a commit.
Additionally how many percentage of errors relate to typing and are solved by static typing? Don't get me wrong, I have really used C, C++, Java, C# and Ruby for a lot of projects. In my experience basic "types" are reminiscent of cpu architectures; they are a small subset of categories or classes. Beyond standard library you have a lot of risks in correctly programming the business domain. So atatic types don't help me much.
That said, static types do indeed help with other problems in software development. If nothing else, writing software using a language with static types means there will be fewer tests you should write to catch silly errors, leaving you free to focus on the truly hard parts of your problem domain; in some sense you can consider types as a kind of test the compiler automatically writes for you. Because powerful type systems can encode a lot, I'd say the answer to "how many errors relate to typing" is also "a lot". For example, do you consider a NullPointerException in production an error? I do, and I've seen plenty of them.
Also, consider that Go is probably not the best exponent of static typing out there, so you should be careful not to confuse "flaws with Go" with "flaws with static typing".
Ok the more low-level a language is the more you will have control on everything, but hey, Go is not ASM and you will still risk making mistakes.
Even having just one error you didn't think of, then when it presents itself and you're coming back to the code after months, I'm not sure which language, Ruby or Go, will be more pleasant on you..
It doesn't have Go, but it walks you through Ruby, Io, Prolog, Clojure, Scala, Erlang, and Haskell. It will give you a wide basic understand of why design tradeoffs have been made.
I do think people recognize the fact that these two are different things (e.g. when comparing C to a language with a richer standard library it's one of the points that are often specifically and separately mentioned.), but it's just not very useful to separate them explicitely in a comparison of languages from a user's point of view (as opposed to a language designer's point of view).
You have to remember all these tricks :
https://github.com/golang/go/wiki/SliceTricks
You can't even wrap them into functions or you'd have to write type assertions everywhere.
Now,you could define a custom Array type with methods, but goodbye type safety. It's funny how sometimes Go works better as a "dynamically typed" language than as a statically typed one.
Ruby on the other hand provides loads of methods for every single "core" type.
Ruby's code is more declarative, and seems to use common functional idioms, which make it very easy to understand ("map", "sort", "reverse", "take" mean mostly the same in a wide variety of languages). In this case I do not need to know what the computer is doing "close to the metal", just as I do not need to know the physics of asking someone to fetch me a glass of water.
The Go snippet is also easy to understand, but it has more noise in the form of boilerplate. Here the name of the function is more helpful to understand what it's supposed to do. If the function was named GuessWhatThisDoes I'd figure what it does, but I'd have a harder time than with the Ruby version.
To be honest, both snippets can be understood, but unless I truly needed to understand the step-by-step performance implications, I'd rather read the more declarative Ruby snippet.
If that line would be "optimized for readability", there would be at least one or two intermediate variables.
Intermediate variables in functional languages are largely used for memoization. Occasionally are they used for self-documentation but generally I see "people.map(&:full_name)" over "full_names = people.map{ |p| p.first_name + ' ' + p.last_name }".