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throwaway34241 | 4 years ago

I think C# might be the closest mainstream language, but I’d say explicit pointers, interior pointers, and slices as the default list type might be things that make Go programming a little lower level.

There are also other differences that would prevent using C#’s system as is - Go doesn’t have the reference/value type dichotomy or inheritance. I think they also wanted to be able to abstract across float/doubles etc (unless C# added that recently).

Anyway I like both languages and I’m not trying claim one is better than the other, just trying to explain the design space Go seems to occupy.

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staticassertion|4 years ago

I'm not sure what the difference is with regards to pointers. They're both garbage collected languages with value types.

There are definitely differences in the languages, but I'm not sure that Go really had anything to figure out or invent. I don't buy that argument.

throwaway34241|4 years ago

> I'm not sure what the difference is with regards to pointers.

In C# most objects are 'class' objects, which are implicitly passed by pointer, although some are 'struct' objects passed by value. In Go rather than making the decision once at the type level, the decision to pass by value or pointer is made explicitly every time an object is used.

> I'm not sure that Go really had anything to figure out or invent

If you look at the discussions for Go (which started as early as 2009 [1]) [2] [3] [4] [5] generics seems as big or a bigger project as the other improvements made to the language over the last decade. My impression is there being a broad spectrum of potential trade-offs across compile speed, execution speed, convenience, etc.

The totality of the prior art here is above my pay grade, but I can quote the Haskell people they roped in [4]:

> We believe we are the first to formalise computation of instance sets and determination of whether they are finite. The bookkeeping required to formalise monomorphisation of instances and methods is not trivial ... While the method for monomorphisation described here is specialised to Go, we expect it to be of wider interest, since similar issues arise for other languages and compilers such as C++, .Net, MLton, or Rust

I think C# occupies a fairly nice design spot also (and takes advantage of its class/struct system to get fast compiles but also performance when needed). But it's not like the C# design couldn't be improved on. As far as I know you still can't write math code that works across 32 and 64 bit floats. And array covariance is implemented in a way that isn't type-safe and relies on run-time checks and exceptions. [6]

[1] https://research.swtch.com/generic

[2] https://docs.google.com/document/d/1vrAy9gMpMoS3uaVphB32uVXX...

[3] https://go.googlesource.com/proposal/+/master/design/go2draf...

[4] https://arxiv.org/pdf/2005.11710.pdf

[5] https://go.googlesource.com/proposal/+/refs/heads/master/des...

[6] https://codeblog.jonskeet.uk/2013/06/22/array-covariance-not...

pjmlp|4 years ago

Never used unsafe and raw pointers in C#? They exist since version 1.0.

Never used ArraySegments in C#? They exist since version 2.0

Abtracting over float/doubles is called generics.

socialdemocrat|4 years ago

It is not the same thing at all if you care to compare the details. C# pointers come with a long list of caveats which does not apply in Go. They feel like a bolted on escape hatch rather than a real part of the language.