I have this type implementation:
type A struct{
name string
}
func (a A) getName() string {
return "My name is " + a.name
}
How I can change implementation of method getName() for this type using reflection? For example, I want use next implementation instead of current:
func newGetName() string {
return "test reflection"
}
分享 Go is a compiled language. As such, it's not possible to modify the implementation of things at runtime. What you can do is changing the place function pointers point to:
var getName func(string) = func(name string) {
return "my name is " + name
}
In order to make this work with a structure, you have to resort to a few tricks. First add getName as a member to A:
type A struct {
name string
getName func() string
}
Then we enclose a pointer to the structure as an implicit (i.e. closed over) parameter:
foo := &A{name: "Hans"}
foo.getName = func() string {
return "my name is " + name
}
Now you can call A.getName() and the result is "my name is hans". You can use method expressions and many other features just fine, but getName is a structure member and not a method of A, so keep this in mind. When you want to give a new meaning to getName, assign something different to it:
foo.getName = func() string {
return "test reflection"
}
Another idea that is especially applicable if you know in advance what implementations getName could have is to add a new member to A that says what implementation getName currently has and then switch over this variable.
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