Go kit: Go in the modern enterprise

Re:Go kit: Go in the modern enterprise by Zikes on Thursday February 12, 2015 @12:09AM (#9037497)

How about an array of Media?

    package main

    import (
        "encoding/json"
        "fmt"
    )

    type Media struct {
        Title        string
        Price        float64
        PurchaseType string
    }

    func main() {
        jsonData := []byte(`
            [
                {"purchaseType":"Rent","price":0.99,"title":"Inception"},
                {"purchaseType":"Free","price":0.00,"title":"Johnny Mnemonic"},
                {"purchaseType":"Buy","price":17.99,"title":"John Wick"}
            ]
        `)
        var media []Media
        err := json.Unmarshal(jsonData, &media)
        if err != nil {
            fmt.Println("error: ", err)
        }
        fmt.Printf("%+v\n", media)
    }

Output:

    $ go run main.go
    [{Title:Inception Price:0.99 PurchaseType:Rent}
    {Title:Johnny Mnemonic Price:0 PurchaseType:Free}
    {Title:John Wick Price:17.99 PurchaseType:Buy}]

Edit: Regarding the MediaType: http://stackoverflow.com/questions/14426366/what-is-an-idiom...

[ Parent | on HN ]

Re:Go kit: Go in the modern enterprise by sagichmal on Thursday February 12, 2015 @03:32AM (#9037979)

PurchaseType doesn't need to be stringly typed. See https://talks.golang.org/2015/json.slide#1.

    type PurchaseType byte
    
    const (
        Free PurchaseType = iota
        Rent
        Buy
    )
    
    func (t *PurchaseType) UnmarshalJSON(data []byte) error {
        var s string
        if err := json.Unmarshal(data, &s); err != nil {
            return fmt.Errorf("purchase type should be a string, got %s", data)
        }
        have, ok := map[string]PurchaseType{"Free": Free, "Rent": Rent, "Buy": Buy}[s]
        if !ok {
            return fmt.Errorf("invalid purchase type %q", s)
        }
        *t = have
        return nil
    }

That's enough to give this output:

    [{Inception 0.99 Rent} {Johnny Mnemonic 0 Free} {John Wick 17.99 Buy}]

http://play.golang.org/p/dyNVlgmFtu

[ Parent | on HN ]

Re:Go kit: Go in the modern enterprise by codygman on Thursday February 12, 2015 @12:16AM (#9037514)

Check out my update if you haven't seen it already.

tl;dr The problem for me personally is when you start making functions based on the type of media and sacrifice type safety if MediaType is a string.

[ Parent | on HN ]