directfunc

Direct funcs

Register a signature by embedding DirectFuncVal and binding a method. This example makes interpreted func(int) int values ordinary Go functions:

package myint

import "github.com/goplus/ixgo"

type fn struct{ ixgo.DirectFuncVal }

func (c fn) Int(n int) int {
	return c.Call(n).(int)
}

func init() {
	ixgo.RegisterDirectFuncFor(func(c ixgo.DirectFuncVal) func(int) int {
		return fn{c}.Int
	})
}

src := `package main
func main() {
	add := func(x int) int { return x + 1 }
	println(add(41))
}
`
ixgo.RunFile("main.go", src, nil, 0)

func() is built into ixgo. Import this package for common func() T results.

import _ "github.com/goplus/ixgo/directfunc"

Registered signatures:

• func() bool
• func() int / int8 / int16 / int32 / int64
• func() uint / uint8 / uint16 / uint32 / uint64 / uintptr
• func() float32 / float64
• func() string
• func() error

Named types (for example type Action func()) stay on reflect.MakeFunc unless the host registers them.

A later registration for the same signature replaces an earlier one. Passing a nil maker to RegisterDirectFunc, or a nil bind to RegisterDirectFuncFor, removes the registration. Do not unregister or replace a signature while function values of that type are still in use.