pack_func_handle_arg.go

/*!
 *  Copyright (c) 2018 by Contributors
 * \brief Sample golang application to demonstrate converted packed
 * function handle passed to another packed function.
 * \file pack_func_handle_arg.go
 */

package main

import (
    "fmt"
    "./gotvm"
)

// sampleCb is a simple golang callback function like C = A + B.
func sampleCb(args ...*gotvm.Value) (retVal interface{}, err error) {
    for _, v := range args {
        fmt.Printf("ARGS:%T : %v\n", v.AsInt64(), v.AsInt64())
    }
    val1 := args[0].AsInt64()
    val2 := args[1].AsInt64()
    retVal = int64(val1+val2)
    return
}

// sampleFunctionArg receives a Packed Function handle and calls it.
func sampleFunctionArg(args ...*gotvm.Value) (retVal interface{}, err error) {
    // Reveive Packed Function Handle
    pfunc := args[0].AsFunction()

    // Call Packed Function
    retVal, err = pfunc.Invoke(args[1], args[2])
    return
}

// main
func main() {
    // Simple convert to a packed function
    fhandle, err := gotvm.ConvertFunction(sampleCb)
    if err != nil {
        fmt.Print(err)
        return
    }

    gotvm.RegisterFunction(sampleFunctionArg);
    fmt.Printf("Registered: sampleFunctionArg\n")

    funp, err := gotvm.GetGlobalFunction("main.sampleFunctionArg")
    if err != nil {
        fmt.Print(err)
        return
    }

    retVal, err := funp.Invoke(fhandle, 10, 20)
    if err != nil {
        fmt.Print(err)
        return
    }
    fmt.Printf("Result:%v\n", retVal.AsInt64())
}