Examples

Simple stopwatch

An example of a proxy that measures and prints time taken for every method invocation:

Go

package main

import (
    "fmt"
    "reflect"
    "time"

    "github.com/ovechkin-dm/go-dyno/pkg/dyno"
)

type Greeter interface {
    Greet() string
    SayHello(name string) string
}

type SimpleGreeter struct {

}

func (g *SimpleGreeter) Greet() string {
    return "Hello!"
}

func (g *SimpleGreeter) SayHello(name string) string {
    return fmt.Sprintf("Hello, %s!", name)
}

type StopWatch[T any] struct {
    Impl T
}

func (p *StopWatch[T]) Handle(m reflect.Method, values []reflect.Value) []reflect.Value {
    before := time.Now()
    result := reflect.ValueOf(p.Impl).MethodByName(m.Name).Call(values) 
    after := time.Now()
    fmt.Printf("Method %s took %v\n", m.Name, after.Sub(before))
    return result
}



func main() {   
    greeter := &SimpleGreeter{}
    stopWatch := &StopWatch[Greeter]{Impl: greeter}
    dynamicGreeter, err := dyno.Dynamic[Greeter](stopWatch.Handle)
    if err != nil {
        fmt.Println("Error creating dynamic greeter:", err)
        return
    }

    fmt.Println(dynamicGreeter.Greet())
    fmt.Println(dynamicGreeter.SayHello("World"))
}