Idiomatic Go (2016)(dmitri.shuralyov.com)
dmitri.shuralyov.com
Idiomatic Go (2016)
https://dmitri.shuralyov.com/idiomatic-go
71 comments
> > Avoid unused method receiver names
> That's just "don't create a non-static method if you don't use 'this'" in other languages with classes.
I don't think that's what's meant. It means to write `func (Receiver) Method()` rather than `func (r Receiver) Method()` when you don't use `r`. Sometimes you need this to implement an interface like `error` or `Stringer` and you just don't need instance data.
(I'm no Go apologist but I think "receiver" is a great term. It's clear, it's applies to other languages and paradigms, and it doesn't really have an alternative that I'm aware of.)
> That's just "don't create a non-static method if you don't use 'this'" in other languages with classes.
I don't think that's what's meant. It means to write `func (Receiver) Method()` rather than `func (r Receiver) Method()` when you don't use `r`. Sometimes you need this to implement an interface like `error` or `Stringer` and you just don't need instance data.
(I'm no Go apologist but I think "receiver" is a great term. It's clear, it's applies to other languages and paradigms, and it doesn't really have an alternative that I'm aware of.)
The term “receiver” comes from Smalltalk: http://www.bitsavers.org/pdf/xerox/parc/techReports/SSL-76-6...
That makes sense. I just about figured it would. :-)
> P.S. I never understood why Go uses words like "receiver" and "marshaling" that are rarely used elsewhere
What else are you familiar with? Those are extremely common terms in the object oriented community.
What else are you familiar with? Those are extremely common terms in the object oriented community.
Method? Serialize?
A receiver isn't a method. It's the "self" instance the method is invoked on. It's standard OOP terminology.
I'm with you regarding marshaling, but not because it's not an industry-standard term, it's just that Go misapplies it. Marshaling historically has referred to describing a remote procedure call and its return value; for example, you call "CreateFoo()" with a "CreateRequest", the latter must be marshaled into a payload that the remote call can read. For a network call this requires serializing the data to bytes using some kind of format, but for a local call it could just be a pointer to a data structure. However, historically people have often mixed the two terms. Python's standard library also misuses "marshal" to refer to serialization.
I'm with you regarding marshaling, but not because it's not an industry-standard term, it's just that Go misapplies it. Marshaling historically has referred to describing a remote procedure call and its return value; for example, you call "CreateFoo()" with a "CreateRequest", the latter must be marshaled into a payload that the remote call can read. For a network call this requires serializing the data to bytes using some kind of format, but for a local call it could just be a pointer to a data structure. However, historically people have often mixed the two terms. Python's standard library also misuses "marshal" to refer to serialization.
The history on marshaling goes back further than that. Smalltalk used the word more or less how it’s used in Go. There is definitely an RPC connotation these days though, probably because small talk was based on message passing.
> (P.S. I never understood why Go uses words like "receiver" and "marshaling" that are rarely used elsewhere)
Not sure about receiver, but marshaling has been part of Python's lingo for ages.
Not sure about receiver, but marshaling has been part of Python's lingo for ages.
The term 'receiver' has a long and distinguished history.
Alan Kay used it, Smalltalk used the word almost exclusively.
If Zoomers don't know their computer science history that's on them.
> Alan Kay used it, Smalltalk used
So Alan and the language he helped create. That’s double counting the sample of 1
So Alan and the language he helped create. That’s double counting the sample of 1
“Marshaling” became pretty ubiquitous as a term in the 1990s with CORBA and Microsoft OLE/COM.
> That's just "don't create a non-static method if you don't use 'this'" in other languages with classes
Go doesn't have static methods. Regardless if you name the receiver, you have to provide an instance of the type to all methods. Maybe you should check your own knowledge before criticizing others
Go doesn't have static methods. Regardless if you name the receiver, you have to provide an instance of the type to all methods. Maybe you should check your own knowledge before criticizing others
They said “in other languages with classes”. They are comparing to a common code review but/gripe in other languages besides Go.
I’ve worked with people who raised comments like these in PRs and they were a nightmare: always arguing, never listening to anyone but themselves, and generally full of ego. Good developers but often slow to deliver too.
If you’re focused on what character of “GitHub” or “oauth” should capitalised in a variable name, then you really are focusing on the wrong problems of software development.
If you’re focused on what character of “GitHub” or “oauth” should capitalised in a variable name, then you really are focusing on the wrong problems of software development.
There is value in having local consistency, which is usually achieved through having rules.
The more uniform a code base, the easier it is to breeze around and get stuff done. Naming things is already hard, so having rules around the annoying bits is nice.
The more uniform a code base, the easier it is to breeze around and get stuff done. Naming things is already hard, so having rules around the annoying bits is nice.
Rules are best handled by automated tools with as few configuration options as possible - like gofmt or black.
This way people won't start bikeshedding about the placement of curly braces, they either accept the style or move on.
It also prevents things from getting political or personified. It's the tool that's making the decisions, not a specific person.
This way people won't start bikeshedding about the placement of curly braces, they either accept the style or move on.
It also prevents things from getting political or personified. It's the tool that's making the decisions, not a specific person.
This is why I push for gofumpt over gofmt
These rules aren’t really about naming things, which I agree is hard. It’s pedantry around terms that really don’t matter which way you choose and thus are categorically not “best practices” let alone “idioms” one must abide by.
If the author really cares this much then they should be linter rules instead of a blog post.
If the author really cares this much then they should be linter rules instead of a blog post.
I don't know, code that isn't at least internally consistent with itself in capitalization is a pet peeve. There should be one way to do a thing.
When is agree when talking about all caps terms like HTTP or even just camel case verses snake case. But it’s really scraping the barrel of usefulness when you’re debating whether the H in Github or A in OAuth is capitalised.
Just write a linter rule and be done already.
Just write a linter rule and be done already.
Github has a neat extension to its' markdown syntax where if you comment with a block for a specific line or lines, it will render to have a "commit suggestion" button.
```suggestion
my_change
```
if there's someone on your team prone to style nitpicks like this, this can often sate them, and it's convenient for you to merge into your branch
```suggestion
my_change
```
if there's someone on your team prone to style nitpicks like this, this can often sate them, and it's convenient for you to merge into your branch
A project should have an .editorconfig setup that automatically hints or enforces the correct code style in the IDE.
> When reviewing Go code
This article reads as a parody of the worst sort of code review. This seems to be a person who sees themselves as little more than a regex engine.
Were I writing a go codebase in the UK, all spellings would be UK -- because of how absurd it would be to retrain the staff to split their brain on a trivial issue of this kind.
Likewise plurals do not matter, -- double spacing in comment sentences? I cannot imagine comment whitespacing being on the radar of any person one would wish to have as a team mate.
This article reads as a parody of the worst sort of code review. This seems to be a person who sees themselves as little more than a regex engine.
Were I writing a go codebase in the UK, all spellings would be UK -- because of how absurd it would be to retrain the staff to split their brain on a trivial issue of this kind.
Likewise plurals do not matter, -- double spacing in comment sentences? I cannot imagine comment whitespacing being on the radar of any person one would wish to have as a team mate.
Being consistent is the key. When you open up a codebase worked on by 50 people, it's nice when you can't tell who wrote it because of the spelling or whatever. Everyone on the team can see it, think "this looks like I wrote it", and work on it accordingly. That's a good thing.
> Were I writing a go codebase in the UK, all spellings would be UK.
What about if you were in Australia? Germany? Poland? Bulgaria? China?
> how absurd it would be to retrain the staff to split their brain on a trivial issue of this kind.
I've seen this argument used to argue that all the spellings in source code should be US English, always and everywhere. In my opinion, this (being able to use the same argument to argue both for and against the same issue) invalidates the argument entirely.
What about if you were in Australia? Germany? Poland? Bulgaria? China?
> how absurd it would be to retrain the staff to split their brain on a trivial issue of this kind.
I've seen this argument used to argue that all the spellings in source code should be US English, always and everywhere. In my opinion, this (being able to use the same argument to argue both for and against the same issue) invalidates the argument entirely.
So, just to be clear, you think the right level of abstraction that codebase rules should operate at is, "the codebase should be accessible to programmers in every country across the world without modification" even when no such programmers operate on the codebase or are likely to ?
Do you apply this rule uniformly, or just to spellings?
The level of time-wasting here is off the charts. Write code to solve problems. If you have an international team, have international standards, if you do not -- it does not matter.
If any of this changes, literally, apply a regex. OP is a blog article about rules for a code review -- as if the relevant part of the review is spelling ? Are we mad?
Code review isnt to enforce these superficial standards -- these are regexes/flags in a build process. Code review is to ensure the code solves the problem under functional/non-functional constraints, in a manner which is easy to understand, communicates intention, etc.
Anyone talking about whether something is pluralised in a code review is a person who should be no where near any such process. They are clearly pathologically incapable of prioritisation or completely uninterested in review.
Do you apply this rule uniformly, or just to spellings?
The level of time-wasting here is off the charts. Write code to solve problems. If you have an international team, have international standards, if you do not -- it does not matter.
If any of this changes, literally, apply a regex. OP is a blog article about rules for a code review -- as if the relevant part of the review is spelling ? Are we mad?
Code review isnt to enforce these superficial standards -- these are regexes/flags in a build process. Code review is to ensure the code solves the problem under functional/non-functional constraints, in a manner which is easy to understand, communicates intention, etc.
Anyone talking about whether something is pluralised in a code review is a person who should be no where near any such process. They are clearly pathologically incapable of prioritisation or completely uninterested in review.
The link in the "Error variable naming" section seems to directly contradict what the section says.
The link (https://go.dev/talks/2014/names.slide#14) says:
The link (https://go.dev/talks/2014/names.slide#14) says:
Error values should be of the form ErrFoo:
var ErrFormat = errors.New("image: unknown format")
// But if you want to give it a longer name, use "somethingError".
var specificError error
result, specificError = doSpecificThing()
Don't do this:
[...]
var errSpecific error
result, errSpecific = doSpecificThing()
The advice in the 2014 talk applies to exporting specific types of errors as part of a package’s public API surface.
The article, on the other hand, advocates for local variables storing errors not to have distinct names.
The article, on the other hand, advocates for local variables storing errors not to have distinct names.
So a public variable error should follow different naming conventions then a local variable? That doesn't seem right, the go wiki says you should use the 'err' prefix for both (capitalized for public variables though, obviously)
And I'm only asking about when you are giving an error a distinct name, not just naming it 'err'.
And I'm only asking about when you are giving an error a distinct name, not just naming it 'err'.
Idiomatic Go is using shortened variable names, not what's in this article. I thought that was common knowledge and part of the Go ethos? I also wouldn't consider grammar in comments part of the language idioms? This is an unusual and very light take on Golang language idioms.
My understanding is that shortened variable names are recommended for small, tight contexts (loops, short functions) but not generally.
That and conventionally standard names, like r for request/reader, w for writer, etc.
Agreed. Functions shouldn’t be full of short non-descriptly named variables.
The longer the lifetime/scope of a variable, and the more variables there are, the more descriptive the names should be.
Agreed. Functions shouldn’t be full of short non-descriptly named variables.
The longer the lifetime/scope of a variable, and the more variables there are, the more descriptive the names should be.
These are dang short compared to Java's FooBarBazBeanFactoryFuncClassImpl. The point you may be responding to is that "Short variable names" are themselves contextual. If you're doing a simple loop:
for i := range personlist {
person := personlist[i]
...
}
for personNum := range personlist {
person := personlist[personNum]
...
}
I used Golang in a medium and large project. To anyone learning or thinking about learning Go, try it and ignore the online opinions.
I say this as someone who is simultaneously impressed by some parts of it, and gobsmacked at other parts.
Just ignore the dogmatic Gopher priests.
I say this as someone who is simultaneously impressed by some parts of it, and gobsmacked at other parts.
Just ignore the dogmatic Gopher priests.
I'm not angry about it but the fact that Go uses capitalization for access control is just so silly to me. Like something a child might design when figuring out how to hide secrets in a note.
Strong disagree. Using capitalization for access control is ridiculously obvious and simple and clear. Sure, things like "Printf" look odd for a little while.
What is it that you strongly disagree with? That it's silly? I never said it was wrong or harmful, once you know what the rule is I agree that it makes access control obvious - it's just a bit atypical for the capitalization of symbol names to be syntactically significant, no?
I'm not aware of any other language that does this. It's common for other languages to use underscores to indicate that something should be private, but I can't think of another example that uses either capitalization for access control or that embeds syntactic meaning in variable names. To me that makes Go unusual, and for a language that cares greatly about being accessible, unusual choices like this seem silly - not bad or foolish, necessarily - just silly.
I think most people have to be told about the capitalization rule (by the compiler, docs, etc.) because the rule itself isn't that obvious to someone coming from another language, that was my experience at least, and in that sense it feels a bit like a secret handshake to me.
I'm not aware of any other language that does this. It's common for other languages to use underscores to indicate that something should be private, but I can't think of another example that uses either capitalization for access control or that embeds syntactic meaning in variable names. To me that makes Go unusual, and for a language that cares greatly about being accessible, unusual choices like this seem silly - not bad or foolish, necessarily - just silly.
I think most people have to be told about the capitalization rule (by the compiler, docs, etc.) because the rule itself isn't that obvious to someone coming from another language, that was my experience at least, and in that sense it feels a bit like a secret handshake to me.
> To me that makes Go unusual, and for a language that cares greatly about being accessible, unusual choices like this seem silly
I might agree with you if the UC/LC innovation were burdensome to "implement" (i.e. to remember). But, well, it's about as burdensome as understanding that on Unix, a filename that starts with a dot is normally hidden. In other words: instantly grokable and memorable.
I might agree with you if the UC/LC innovation were burdensome to "implement" (i.e. to remember). But, well, it's about as burdensome as understanding that on Unix, a filename that starts with a dot is normally hidden. In other words: instantly grokable and memorable.
I don't mean to nitpick but I'm not arguing that it's burdensome or difficult to remember. I meant it when I said:
> once you know what the rule is I agree that it makes access control obvious
The rule is memorable and grokable, I agree with you! I don't use "silly" to characterize it as the wrong choice, I strictly mean it's a quizzical choice.
Using your hidden file analogy in Unix: if I were to invent a new file system and I decided to use lower case letters to represent hidden files instead of borrowing the "." convention, wouldn't that strike you as a silly choice given the ubiquity of Unix-like filesystems?
> once you know what the rule is I agree that it makes access control obvious
The rule is memorable and grokable, I agree with you! I don't use "silly" to characterize it as the wrong choice, I strictly mean it's a quizzical choice.
Using your hidden file analogy in Unix: if I were to invent a new file system and I decided to use lower case letters to represent hidden files instead of borrowing the "." convention, wouldn't that strike you as a silly choice given the ubiquity of Unix-like filesystems?
Unix has a hegemony that Go doesn't. Go can be a playground for the New Jersey Way.
But sure, I'll sign on to "quizzical". Mainly I'm glad that in Go there's only two levels of visibility, not 3+. Much easier to reason about. Altho I'll admit to being confused when you mix the two levels in the names of a struct and its fields.
But sure, I'll sign on to "quizzical". Mainly I'm glad that in Go there's only two levels of visibility, not 3+. Much easier to reason about. Altho I'll admit to being confused when you mix the two levels in the names of a struct and its fields.
I am obsessively pedantic about grammar and spelling, in code and in English. I have a firm personal preference about how to spell "cancelled"--I like two Ls.
The only reason I'd ever consider telling someone that "canceled" is wrong is if the other spelling was firmly established in the actual codebase. Not in comments. And absolutely not with the ridiculous claim that the language you're coding in has opinions about how to spell your comments.
The only reason I'd ever consider telling someone that "canceled" is wrong is if the other spelling was firmly established in the actual codebase. Not in comments. And absolutely not with the ridiculous claim that the language you're coding in has opinions about how to spell your comments.
In case no one has mentioned it, Learning Go, an Idiomatic approach to real world programming, by Jon Bodner is my favorite Go related book and one of my favorite programming books in general.
https://books.google.com/books/about/Learning_Go.html?id=vjA...
https://books.google.com/books/about/Learning_Go.html?id=vjA...
I love go and everything but this reads more like pedantic go, not idiomatic go.
(2016) Based on the comment/voting entries, first submitted here in 2018.. I wonder if the author feels the same 9 years later.
Here's the idiomatic Go style guide: accept whatever go format outputs. The fact that go formats code by default is one of the best things about the language. The whole point is that spending time either correcting whitespace (or even worse, arguing about how much whitespace to put) is an absolute waste of time and a comradery killer.
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It's the same language that "marshals" and "unmarshals" JSON and "dials" sockets.
Dial is a Plan9-ism and it's hard to argue that it isn't a lot better than the BSD sockets interface.
_jab(4)
For a programming language that makes unused variables a compiler error, I'm surprised there is no clippy/rubocop/black/cargo fmt/clang fmt built-in.
As far as I can tell every single one of those tools was inspired by Go's `gofmt` & `go vet` in the first place.
You mean like “go fmt”?
https://go.dev/blog/gofmt
https://go.dev/blog/gofmt
there is, gofmt :)
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> Avoid unused method receiver names
That's just "don't create a non-static method if you don't use 'this'" in other languages with classes. Which is not a bad idea, but hardly matters. If someone realizes that it's difficult to add a unit test for the function, they'll fix it themselves. Maybe the real question is: did the code author create a unit test for the function?
(P.S. I never understood why Go uses words like "receiver" and "marshaling" that are rarely used elsewhere)
> Empty string check
Sure, but that's just ordinary code smell, likely due to someone not thinking carefully over the code, which could be easily identified in a code review. If it's never found, it barely matters anyway. Is it really worth bringing this up?
Everything else seems unnecessarily boring, like the number of spaces between sentences. Most people I know write comments like how they write regular English sentences, like in emails. Other than a professor who is near retirement age, I don't know anyone who uses double spaces. It's so rare I don't see any point in mentioning it. And if someone did do this in the code, whether it's their style or by accident, I wouldn't even flag it in the code review. For what? Does anyone benefit from it? It's important to have consistency over fundamental things like tab vs space, but that quickly becomes meaningless bikeshedding.
My advice would be: write code using your common sense. Don't be obsessed with trivial things that don't matter. Use your time elsewhere -- push a new feature, fix a bug, add a unit test, or just relax.