package main

import (
    . "github.com/go-andiamo/gopt"
)

func main() {
    optFlt := Of[float64](1.23)
    println(optFlt.IsPresent())
    println(optFlt.OrElse(-1))

    opt2 := Empty[float64]()
    println(opt2.IsPresent())
    println(opt2.OrElse(-1))

    opt2.OrElseSet(10)
    println(opt2.IsPresent())
    println(opt2.OrElse(-1))
}

package main

import (
    "encoding/json"
    "fmt"

    . "github.com/go-andiamo/gopt"
)

type NormalStruct struct {
    Foo string
    Bar int
    Baz float64
}

type OptsStruct struct {
    Foo Optional[string]
    Bar Optional[int]
    Baz Optional[float64]
}

func main() {
    jdata := `{"Foo": null, "Bar": 1}`

    normal := &NormalStruct{}
    err := json.Unmarshal([]byte(jdata), normal)
    if err == nil {
        // was property Foo set???
        fmt.Printf("'Foo' was set to \"%s\"???\n", normal.Foo) // was it really?
        // was property Bar actually set to 0???
        fmt.Printf("'Bar' was set to \"%d\"???\n", normal.Bar) // was it really?
        // was property Baz actually set to 0.000???
        fmt.Printf("'Baz' was set to \"%f\"???\n", normal.Baz) // was it really?
    } else {
        println(err.Error())
    }

    println()
    // now try with optionals...
    opts := &OptsStruct{}
    err = json.Unmarshal([]byte(jdata), opts)
    if err == nil {
        opts.Foo.IfSetOtherwise(
            func(v string) {
                fmt.Printf("'Foo' was set to \"%s\"\n", v)
            },
            func() {
                println("'Foo' was set but not to a valid value")
            },
            func() {
                println("'Foo' was not set at all")
            },
        )
        opts.Bar.IfSetOtherwise(
            func(v int) {
                fmt.Printf("'Bar' was set to %d\n", v)
            },
            func() {
                println("'Bar' was set but not to a valid value")
            },
            func() {
                println("'Bar' was not set at all")
            },
        )
        opts.Baz.IfSetOtherwise(
            func(v float64) {
                fmt.Printf("'Baz' was set to %f\n", v)
            },
            func() {
                println("'Baz' was set but not to a valid value")
            },
            func() {
                println("'Baz' was not set at all")
            },
        )
    } else {
        println(err.Error())
    }
}