Let's Play with Golang 1.18

Slides of the Turin Golang Meetup

Transcript

1. Let's play with Go 1.18!
   Claudio Beatrice - April 27th, 2022
   Having fun fun fun 🕺 with
   
   
   Generics, Fuzzing and Workspace Mode
   

   View Slide

2. Introducing Go 1.18
   This is the best iPhone we’ve ever made
   • It was released on Mar 15th, 2022 , seven months after Go 1.17 📆
   
   
   • It’s one of the major changes in the language ever done 🚛
   
   
   • It packs a TON of new features, plus library and tooling improvements
   
   
   • Generics 㿂
   
   
   • Fuzzing 🎛
   
   
   • Workspace mode 🗃
   
   
   • Sane packages for sorting stuff! 🥇
   
   
   • It keeps the Compatibility Promise, as usual 😎
   

   View Slide

3. Generics
   One does not simply write speci
   f
   ic code
   • Write functions or types that are written work with any of a set of types
   provided by the calling code
   
   
   • Generic code is independent of the speci
   f
   ic types being used
   
   
   • Generics adds three new big things to the language:
   
   
   • Type parameters
   
   
   • Type inference
   
   
   • Interface types as sets of types
   

   View Slide

4. Generics
   Type Parameters
   func Min[T constraints.Ordered](x, y T) T {
   func Min(x, y int) int {
   As opposed to the an equivalent (for ints) monomorphic version
   

   View Slide

5. Generics
   Type Inference
   x := Min[int](2, 3)
   x := Min(2, 3)
   Could be simpli
   f
   ied to
   

   View Slide

6. Generics
   Type Sets
   package constraints
   type Ordered interface {
   Integer|Float|~string
   }
   Interfaces may now be used as type constraints,
   
   
   and they support union of different types.
   

   View Slide

7. Generics
   Bracket beats chevron
   package main
   import "fmt"
   import "golang.org/x/exp/constraints"
   func Min[T constraints.Ordered](x, y T) T {
   if x < y {
   return x
   }
   return y
   }
   func main() {
   fmt.Println(Min[int](2, 3))
   fmt.Println(Min[float32](2.5, 2.6))
   }
   

   View Slide

8. Generics
   Chevron cuts paper
   package main
   import "fmt"
   func Min(x, y int) int {
   if x < y {
   return x
   }
   return y
   }
   func main() {
   fmt.Println(Min(2, 3))
   fmt.Println(Min(2.5, 2.6)) // Error!
   }
   

   View Slide

9. Fuzzing
   Get cover!
   Fuzzing is a type of automated testing which continuously manipulates
   inputs to a program to
   f
   ind bugs.
   
   
   Good for
   f
   inding edge cases: it’s an extremely valuable feat whenever
   security is concerned, and still very valuable to hunt down hard-to-
   f
   ind
   bugs.
   

   View Slide

10. Fuzzing
    Fuzz Anatomy 101
    

    View Slide

11. Workspace mode
    It ain’t much, but it’s honest go work
    • A new, optional go.work
    f
    ile has been introduced: if present, it will set Go
    in Worskpace Mode.
    
    
    • When in Worskpace Mode, go will use the go.work
    f
    ile to determine all
    the modules to use as roots for module resolution, as opposed to having a
    single one as imposed by go.mod
    
    
    • Such Mode allows for work on multiple, independent modules at the same
    time more conveniently than it was in the past
    

    View Slide

12. Workspace mode
    It ain’t much, but it’s honest go work
    go 1.18
    use ../foo/bar
    use ./baz
    replace example.com/foo v1.2.3 => example.com/bar v1.4.5
    

    View Slide

13. New experimental packages
    Sort like it’s 2022
    • https://pkg.go.dev/golang.org/x/exp/constraints
    
    
    • https://pkg.go.dev/golang.org/x/exp/slices
    
    
    • https://pkg.go.dev/golang.org/x/exp/maps
    

    View Slide

14. New networking package
    It’s a net improvement
    • New net/netip package, featuring Addr and AddrPort types
    
    
    • Compared to net.IP, netip.Addr is more memory ef
    f
    icient, immutable,
    comparable and can be used as a map key
    
    
    • Besides an IP and a port, AddrPort can also represent a CIDR pre
    f
    ix
    
    
    • Tons of new functions to work on the newly de
    f
    ined types
    
    
    • Loads of helpers for bridging with the old net.IP package
    

    View Slide

15. And moar!
    Faster and furiouser, sometimes
    • More ef
    f
    icient way to pass function argument on arm64 and some amd64,
    getting up to 10% performance improvements
    
    
    • Due to generics, compile speed can get about 15% slower than go 1.17
    
    
    • Nice strings functions improvements, hello Cut()!
    
    
    • Ditto for bytes
    
    
    • Introduces the new any identi
    f
    ier as an alias for interface{}
    
    
    • Loads of other little minor changes
    

    View Slide

16. Bibliography
    Slides are important, but study is importanter
    • Go 1.18 Release Notes
    
    
    • Article: An Introduction to Generics
    
    
    • Article: Are Go Generics ready for Prime Time?
    
    
    • Documentation: Fuzzing
    
    
    • Reference: Go Workspaces
    

    View Slide

17. Big Pizza Thanks
    There’s food in the Cloud
    

    View Slide

18. Enough talk!
    Pick your poison
    https://go.dev/doc/tutorial/generics 㿂
    
    
    https://go.dev/doc/tutorial/fuzz 🎛
    
    
    https://go.dev/doc/tutorial/workspaces 🗃
    

    View Slide